I'm going to study, watch and listen to all your videos everyday. This is the type of information I've been looking for all along. Thank you so much for uploading these videos. I'm now looking forward to going to flight school and getting my pilots license.
just took the free online course from MIT with these two professors, definitely check out the link in their description. I feel well prepared after these and I’m going to take the actual test in a week
Really like this professor's style. She knows her subject & her personality creates a comfortable & enjoyable atmosphere. Wish I could attend her classes in person.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... For real physics, see this: *rxesywwbdscllwpn.quora.com/* For this video, here are the specifics: . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
an introduction on aerodynamics that explicitely points out equal transit theory as wrong this is freaking awesome it's so widespread and... so clearly wrong on so many sides
@@saltylad2107 or a misapplication of equality in head losses through pipes. I've got an ME bachelor's and my bf has one in AeroE. It's a bad conclusion, but I get exactly why they wanted to make that originally.
21:10 The Wright Brothers did use this exact method to find the best shape for their wing :) They made a bunch of little wings of all different shapes then measured the lift in a small wind tunnel they designed.
What about flat bottom airfoils? I learned higher velocity = lower pressure so the higher pressure air on the bottom pushes up. Demonstrated by blowing over the top of a piece of paper and it lifts up.
A flat airfoil still has to have angle of attack to produce lift so it's still deflecting air downward. They tend not be as efficient as more complex airfoils but can be symmetric so they work equally good inverted (assuming you have correct angle-of-attack). I'm not an expert but that is my understanding.
it only works that way if you blow over it in an airplane wing where there's no active blow above the wings (except for very specific types that use the coanda effect for stol capabilities) it's causally the other way round in an airplane the wing deflects air downwards in order to produce lift, therefore the presure above the wing is lower than below th wing, therefor due to the bernoulli efect the air flows faster above than below the wing, not the other way round - it's the same relation bu th causality is the other way round
Plus, AoA trumps airfoil effects. Once you consider symmetrical airfoils, so many of these rudimentary descriptions of "how an airplane flys" just fall apart.
Good communication skills. Nicely explained. You should consider Coanda effect and vortices-shed theory in the list too. I fly the A320 and hate to admit that I still do not know how lift is generated.
This video is fair and has some things ok and some thing wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expectedThis from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom. Cheers
At 12:20 you say "when we have air moving faster over the top of the wing". First of all why is there an assumption that air is moving faster over the top? Second: since top of the wing path is longer for your airfoil and air is moving faster over it, one would argue that time to travel those molecules you mentioned at 7:39 is indeed the same. So, there is a contradiction in your logic.
No contradiction at all. It's not an assumption, we can directly observe it and measure the speeds all around a wing. The air starting in the same place that goes above a wing reaches the trailing edge *much sooner* than the air going under the wing. .. See for yourself in this well known video: The non equal transit time (only) proof video by Holger Babinsky, Cambridge University ua-cam.com/video/UqBmdZ-BNig/v-deo.html Narrated, no title at start Cambridge Univ. This is a poor explanation in many ways. I just reposted my updated analysis of this video in the as its own comment. Regards
> Second: since top of the wing path is longer for your airfoil and air is moving faster over it, one would argue that time to travel those molecules you mentioned at 7:39 is indeed the same. Weak logic. You're making an (incorrect) inference that the delta is exactly that required to result in equal transit time when in fact at no point was that stated. Her diagram later in the video showed the top flow arriving at the trailing edge *before* the bottom.
Bernoulli 'happens' in some regions around a wing, but the way it is commonly used is false and Bernoulli's Principle does not give the cause and effect at all, so it is a double fallacy. . . . The real reason the air above a wing speeds up toward the trailing edge is the decreasing Pressure Gradient from the leading edge to above the wing. . Speed does not cause a decrease in pressure. Following up on Bernoulli's work in the mid 1700s, Euler determined that a Pressure Gradient in a region provides the force to accelerate fluid toward the lower pressure [because the higher pressure region pushes more than the lower pressure region. . The pressure decrease is because the flow is curved as it is directed over the leading edge. It would continue upward, but atmospheric pressure is still pushing downward. It doesn't go away when the wing starts moving. The tendency to continue upward {Newton's First Law] works against that, thus reducing the pressure a small bit. It is the very same as you feeling lighter at the top of a fast roller coaster hill - your body 'wants' to continue upward, thus working against gravity. . Don't forget Newton's First Law. Inertia applies. . Following up on Bernoulli's work in the mid 1700s, Euler determined that it is a pressure difference between two locations, called a "pressure Gradient" that provides the force that Accelerates air toward the lower pressure - where that moving flow now assumes that lower pressure. .. Bernoulli's Principle itself, refers to a speed INCREASE, which is acceleration, in a region being ACCOMPANIED BY a pressure decrease across the that SAME region. It does not say that one causes the other. It ONLY acknowledges the relationship. Per John D. Anderson's book, there is no indication that Bernoulli understood the cause and effect. . . .
I'm still pretty sure that the air over the top of the wing travels faster because it is displaced more than air under the bottom of the wing. And hence, faster air makes for lower pressure (Bernoulli) thus generating part of the total lift. Several factors contribute to lift. Perhaps the equal transit theory is just a way to illustrate Bernoulli's by comparing 2 air molecules, 1 above and 1 below the wing.
@@jameswalker3463 Same answer as for Nitin Tiwari, above, pretty much. Upside down you can use the ailerons to create a camber on the airflow, or the tail surfaces to give you the angle of attack you want to give you lift. This is Lecture 2, the straight and level part of the overall configuration of forces that you'll learn, assuming you're not just carping about something you already know, that is.
@@David_Lloyd-Jones A lot of the assumptions required for Bernoulli's equation is not valid in case of plane wings. Have a look: en.wikipedia.org/wiki/Bernoulli's_principle . Though you can say that it applies approximately but since it is not 100% correct you can't use it as an argument to explain lift. @James Walker when the plane flies upside down the lift acts in the opposite direction i.e. lift acts towards the ground (this will again depend on the wing configuration so it can't be generalized). A good example of negative lift being used is an upside down wing like shape used in F-1 cars to increase downforce and hence traction.
@@nitnisarge When the plane is flying upside down, if the control surfaces (flaps, ailerons. slats...) remained unchanged, you would certainly be right. The "lift" would vector toward the ground. This is not what happens. When the plane it turned over the pilot will change the positions of the ailerons etc. to change the camber of the whole airfoil and hence the flow of the air. Change the bend in the wing by turning the flaps "up," i.e. toward the ground: you have Bernoulli operating in the opposite direction. I'm curious: what do you think you see in the Wikipedia article that shows your " Bernoulli's equation is not valid in case of plane wings"?
Bernoulli's law is rarely taught correctly. Rarely does anyone point out the ambiguity in the equation: The equation merely states a link between fluid pressure and fluid speed, it does not tell you what causes what. A pressure difference between two points in space causes fluid to obtain speed between those two points. The speed of a fluid at a point in space does not cause the pressure seen at that point. Given a fluid speed at a point in space, Bernoulli's law is used to determine the pressure difference that creates that fluid speed. Likewise, given a pressure difference between two points in space...
Yes, it appears that Bernoulli is misinterpreted by the vast majority of mankind... Then. No equations show cause and effect, only the relationship of values. A difference in pressure between two locations, called a Pressure Gradient, causes *acceleration* toward the lower pressure, NOT speed! A *change* in speed or velocity is acceleration. If fluid is moving toward a higher pressure, the speed will decrease - a NEGATIVE acceleration.
@@Observ45er Fluid obtaining speed is acceleration. The speed of a fluid is brought about by acceleration. The point of my comment is to point out that teachers too often tell students that the change in speed or velocity of a fluid causes a change in pressure, which is an incorrect interpretation of the equation.
@@exilesurvivor1053 Precisely my point. So is fluid slowing and fluid flow curving. People don't understand the science. Acceleration is also *any change* in velocity and many amateur scientists trying to explain this, as well intended they may be, don't understand and only repeat the wrong info. Pressure Gradients CHANGE velocity (Acceleration), NOT cause increased speed. People think acceleration is only "speeding up". . Watching a wing go by, you see THE *SAME accelerations,* but *different speeds*, so it is misleading to talk speed. .. If you truly understand the science/physics, the fact that the air under the wing is faster, AS A WING PASSES YOU BY, will be no surprise to you.. Look at fig. 7 here: rxesywwbdscllwpn.quora.com/
@@Observ45er Velocity is a measurement we invented that represents rate (speed) of something in terms of components of a coordinate system. Speed is simply magnitude of a velocity. In one dimensional motion, speed exists in only one dimension, thus speed and velocity are the same, or specifying the direction of the speed (velocity) is pointless. Even in two dimensional motion, the speed in one dimension may dominate. Pressure gradients DO increase the speed of a fluid. Air underneath a wing experiencing lift in the direction perpendicular to the upper surface is SLOWER than the air above the wing. The pressure above the wing becomes lower than the pressure below the wing because the orientation of the wing creates a void (relatively speaking) above the wing as the wing moves forward and displaces air molecules, and because air molecules under the wing collide with the wing surface and are deflected as the wing moves forward.
@@exilesurvivor1053 You have some ideas there that are understandably misleading. . Things can move only along a single path which for computational convenience, we separate into the three orthogonal component directions. You can say that we invented these three dimensions. . For motions, those are called components and they add vectorially. None “dominates”. It is simple vector addition and a larger component contributes more to the resultant direction and magnitude. . Speed is not a one dimensional only phenomenon. In curved movement the direction is constantly changing, therefore it cannot exist on only one dimension. It can have an instantaneous speed that must be in only one direction. However, because speed is a distance traveled over a time, the requirement of time in this quantity makes one dimensional speed meaningless.. . Pressure Gradients Accelerate fluid and the direction of (positive) acceleration is the same as the direction of the force. F=MA is a vector equation where F and A are collinear. . Therefore, a force can increase the speed, decrease the speed, or change the direction of existent travel. These are all Acceleration. . Therefore, changing direction is not meaningless. A force with some component not colinear to the current direction of travel will change that direction over time and this is also acceleration. When the direction of that force always points to a fixed location, this is called centripetal acceleration. .. Above a wing, your ‘void’ (lower pressure) is caused by the air’s inertia/momentum trying to go straight and thus lowering the pressure toward the convex curve against the atmospheric pressure holding it to the surface. This forms the Pressure Gradient across the flow. This lower pressure along with the relatively higher atmospheric pressure farther AHEAD of the wing accelerates air rearward, toward the trailing edge. ALSO, this lower pressure along with the relatively higher atmospheric pressure farther ABOVE the wing accelerates air downward joining (NOT re-joining) the lower air in the downwash behind the wing. .. .. .. Below AND above the wing, molecule are *always* 'colliding with the surface’. However, below the wing the inertia or momentum increases the pressure there and this *curves* the flow downward because the Pressure Gradient is across the flow giving centripetal acceleration. .. .. .. .. .. .. The under wing air is only slower from the wings frame of reference. Watching a wing go by in still air, measurements show the air under the wing is faster than the upper air. Relative to the still air mass, the *under-wing air* is accelerated to a *higher speed* (magnitude) than the air above. (measured data shows this) YET the accelerations observed in either view are the same and this is what needs to be understood about Bernoulli’s Principle. . Bernoulli’s Principle tells about pressures associated with *changes in velocity* which is acceleration, NOT simply increased speed. .. The air exiting any blower into the atmosphere is at that SAME atmospheric pressure, not lower. The energy of the higher pressure air *INSIDE* the blower accelerated it into the relatively lower atmospheric pressure outside the blower. ... ... ... ... Relating Bernoulli’s Principle to speed is one of the biggest myths held by amateur scientists that has persisted for a long time. . Please see these correct explanations of Bernoulli’s Principle and Lift. rxesywwbdscllwpn.quora.com/ Regards
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
@@Observ45erUr quite excellent in that analysis. I. Picked up most, almost all of what u highlighted too. Sometimes I wonder if these lectures got some high ranking, more experienced seniors to monitor what they actually teach the students. Coz such errors of omissions can determine whether a student fails or passes this course. And my man u qualify to be a senior supervisor above such lectures. Be blessed
@@kensimba7868 Thanks. She's supposed to have a advisor right there, also. Unfortunately, too many people don't really understand the physics. . I'm an experienced electrical engineer and took responsibility for a sophisticated flight simulator about 10 years ago. Since it had been years since I had ground school (I never went for the private license) and decided to brush up on some things because the students might ask any kind of question. I saw the three most common misconceptions about lift repeated over and over again. So I read some of the well known aerodynamics texts and even contacted a couple of the authors to discuss some of these things. One of my sons is an aeronautical engineer and he was very helpful in discussing a lot of this. My dad was also an engineer and he had this intense desire to understand things correctly and I guess I inherited it. He also had a private license that he got while learning to fly in biplanes, so I spent a fair amount of time in my youth around airports and other pilots. . I've mentored others in the Navy and throughout my professional career and taught at two community colleges. If I'm going to explain something I'm going to understand it well first. . I have a Blog that gives the full physics for the fundamental concept of lift as well as the correct Bernoulli's principle: rxesywwbdscllwpn DOT quora DOT com/ Cheers
The exact detail of how an aircraft flies is not projected well. There are some misleading issues in this video. Bernoulli does not explain some details appertaining to flying. In flying most issues can be explained through dynamic forces generated by mass being ACCELERATED and so that would be the RATE OF CHANGE OF MOMENTUM and not momentum.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
MIT instructor talks about how she was going educate her students to greater levels than the FAA requrires, then goes on to refer to a "big jet engine with seats inside it " instead of saying "trasnport category aircraft >.
This video is fair and has some things ok and some thing wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. OK -- 6:12 Explains Equal transit, longer distance. Points to flat wing, same length. Math description not needed. Good Aeroastro graphics. 12:01 OOD Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD stationary pressures. 15:14 asks childish questions. Race Car. 16:36 Only says the spoiler “spoiles the air flow. Doesn’t explain that it has down lift. 18:09 Wing changes the speed of the air ALSO. Never states that upper air beats lower air. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio withoug explaining it. 24:24 Mentions hand out car window and PUSHING, but dowsn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Comperssibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kitta Condition and says wrap around is an additional condidtion. 2D is simpler ) OK, but tip vortex in not true turbulence. So… Calculat where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between. 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
I'm sure it's very hard to answer questions on the spot like this and I'm no physics major but not only are a lot of the answers and explanations incomplete in my opinion, this feels a lot like when you ask a teacher in high school something they don't understand and they try to over simplify in an obvious way. I liked this lecture but this isn't the standard I was expecting from MIT unfortunately. Quick note: I don't believe she doesn't understand certain concepts, but teaching requires being able to explain concepts very clearly. Some could be the best at their job or skill but still not be able to teach it in the slightest.
I agree, and I think its because she's a private pilot, not a CFI. ie, not an expert. Seems like there's a bit of a gap between her expertise in another genre? of engineering and teaching. I'm studying for my CFI and am wondering how I will handle questions from students I have no idea how to answer.. 😂
@@dt10825 I think one of the best things to hear when someone doesnt know the answer is just for them to admit they don't fully know and that they'll find out. You can't expect a teacher to know everything but a good teacher wont try to fake an explanation but will do their research and have the answer for future students. Especially when it's a complicated subject which the student could have difficulty understanding by doing their own research.
Yes. unfortunately it's a plaguing issue in aviation across all levels and it causes accidents. There is a lingering fear of judgment and being called out within the aviation community. Something more important than knowing stuff is knowing how to reference the right materials.
Danny if in doubt always admit it and do some research, nothing wrong with learning as a CFI, I still try to learn as much as possible being a CFI.but there’s not point in feeding wrong information and ruining a students first experience to a subject, especially as this can this can cause miscommunication and lack of correct knowledge (primacy)!!
@@JulianDanzerHAL9001 Complicated for sure. My understanding is that the elevator turns the aircraft. Any "horizontal component of lift" will tend to push the plane sideways (translation) not turn it (torque.) You may get a little torque due to the vertical stabilizer causing some weathevaning, but up elevator pulls the nose through the turn. It is the most powerful torque arm in the system. I think the best tool is to imagine an aircraft with a symmetrical airfoil. There is no "horizontal component of lift" in a roll - all your lift is due to AoA, and all that AoA is due to elevator.
@@MatthewHarmon it's a combination of those a horizontal component of lift changes the velocity of the plane, making it fly in adifferent direction what actually turns the nose of the plane in that direction i a combination of rudder, elevator and aerodynamic stability if you fly a several G turn i na jetfighter it's mostly elevator an daerodynamic stability if you fly a regular turn in an airliner it's mostly rudder and aerodynamic stability if you fly a turn without rudder it's urely aerodynamic stability - which is the easiest way to fly a turn though a bit uncomfortable
@@MatthewHarmon of course it depends on the type of plane in a b2 bomber it's mostly differenctial airbrakes that turn the nose and all these effects influence each other which then influnece each other back
@@MatthewHarmon Julian is correct. You're confusing what controls are used and the forces. A curved path is an acceleration, no matter what the object. That force comes from the horizontal component of lift. .. Maintaining the craft's orientation to the relative wind in order to maintain the turn, is done with the controls. That very old mantra that the elevator turns the plane is only partly true because it also gets the AoA to simultaneously hold the airplane *UP* ! Since more total force is required to now support the plane AND supply sideways force, elevator is used to increase AoA for the needed increase in lift. This is a prime example showing that pilots need to know how to control the craft and do not really need the deep science of all of it.
you may have learend more from flying a cropduster... for years - than you will during th first half hour at mit... but much of what you learn fro mflying a cropduster are probably misconceptions and simplifications that work half decently if flying a cropduster is all you want to do but are going to be catastrophic if you try to go into research or development and desing new airplanes
@@dheujsnrhfydhehehshshhdggsd it's for flight instruction at mit it's flight instructions aimed at people who do both and thus need a deeper understanding of things as well
I still believe in equal transit theory. You would never be able to prove this in a wind tunnel because the air is moving past the wing, but in real life, in the sky, your wing is moving through the air.
brotein she explained that earlier in the video. It's about point of reference. From the wing's point of view the air is moving past the wing, but from the air's point of view the wing is moving past the air.
@@macman603 it may well be that the "equal transit" theory is wrongly stated.. but even herself in her presentation stated when presenting Bernoulli'sLaw ( that is not a myth ) that the air on top goes indeed faster.. then reducing pressure and then the pressure differenctial creates lift.. otherwise since it is a longer distance if the air does not increases speed it should be creating either vacum.. or a lower density air area.. either way there will be less pressure on the longer way ( on top in this case..) so in content what the equal transit theory states is not really a mith.. the result is there to see..
and moreover.. it is a false that to create lift you need an angle of attack between the fluid and the foil shape.. you do if the shape is flat in both sides as is the case in a paper airplane wing but its proven hat a foil shape creates lift even without air 'hitting" the bottom... although that could add even more like for instance when an airplane is landing at low speed..
this is mit, not your backyard flightschool so it's good for them to learn how and why things work, not just how to act with them while spreading misconceptions about the why
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... For real physics, see this: *rxesywwbdscllwpn.quora.com/* For this video, here are the specifics: . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying... . 0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned. There is only ONE wing. Going to talk about sea planes ??? 3:11 initially says lift exceeds drag, but corrects it. 4:50 Draws an extreme airfoil shape. 5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction". 5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs. 6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics. 12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast. 12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli.. 12:42 The Graphic assigns INCORRECT cause to lower pressure. 14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force! 15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary. 15:57 Asks childish questions. Race Car. 16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift. 18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!! 18:09 Wing ALSO changes the speed of the air. Never states that upper air beats lower air. 18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood. 18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification. 23:40 Mentions aspect ratio without explaining it. 24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier. 25:28 Mentions Viscosity. Compares sticky. Sticks to the wing. 27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY. 27:20 Calculating lift is not known. 29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere. Doesn’t explain chord line. Says: “in between". 32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference. 38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed. 42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed. 47:38 Only explains that roll is around the longitudinal axis, but not the others. 48:13 Doesn’t explain why adverse yaw occurs. 48:15 Stability OK. 53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable. 54:45 First mentions separation. 55:56 climb & decent, lift = weight. 57:15 Torque causes a left ROLL. 57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at 1:02:20 Precession is 90 degrees later. 1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw. In zero G flights confuses the upward parabola with top and downward parabola with bottom.
I'm going to study, watch and listen to all your videos everyday. This is the type of information I've been looking for all along. Thank you so much for uploading these videos.
I'm now looking forward to going to flight school and getting my pilots license.
just took the free online course from MIT with these two professors, definitely check out the link in their description. I feel well prepared after these and I’m going to take the actual test in a week
Ji
Did you get your license yet?
I fell asleep with my phone on and somehow ended up here.
lol
Welcome, friend.
Dude. The exact same thing just happened to me. I fell asleep with my phone on and somehow, I ended up here 😁
Really like this professor's style. She knows her subject & her personality creates a comfortable & enjoyable atmosphere. Wish I could attend her classes in person.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
For real physics, see this: *rxesywwbdscllwpn.quora.com/*
For this video, here are the specifics:
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
an introduction on aerodynamics that explicitely points out equal transit theory as wrong
this is freaking awesome
it's so widespread and... so clearly wrong on so many sides
I feel like the equal transit theory comes about from a misunderstanding of Bernoulli's principle.
@@saltylad2107 or a misapplication of equality in head losses through pipes. I've got an ME bachelor's and my bf has one in AeroE. It's a bad conclusion, but I get exactly why they wanted to make that originally.
21:10
The Wright Brothers did use this exact method to find the best shape for their wing :) They made a bunch of little wings of all different shapes then measured the lift in a small wind tunnel they designed.
They actually measured lift vs drag; a more sophisticated measurement.
What about flat bottom airfoils? I learned higher velocity = lower pressure so the higher pressure air on the bottom pushes up. Demonstrated by blowing over the top of a piece of paper and it lifts up.
A flat airfoil still has to have angle of attack to produce lift so it's still deflecting air downward. They tend not be as efficient as more complex airfoils but can be symmetric so they work equally good inverted (assuming you have correct angle-of-attack). I'm not an expert but that is my understanding.
it only works that way if you blow over it
in an airplane wing where there's no active blow above the wings (except for very specific types that use the coanda effect for stol capabilities)
it's causally the other way round
in an airplane the wing deflects air downwards in order to produce lift, therefore the presure above the wing is lower than below th wing, therefor due to the bernoulli efect the air flows faster above than below the wing, not the other way round - it's the same relation bu th causality is the other way round
She kinda covers it at 9:23
Plus, AoA trumps airfoil effects. Once you consider symmetrical airfoils, so many of these rudimentary descriptions of "how an airplane flys" just fall apart.
Good communication skills. Nicely explained. You should consider Coanda effect and vortices-shed theory in the list too. I fly the A320 and hate to admit that I still do not know how lift is generated.
With the systems on the Airbus 320... ...you don't need to know ;-)
@@saintmichael2759 And I don't want to be one among them. :P
This video is fair and has some things ok and some thing wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
Lift: 4:50
Thank you for all of this great free content !!
You don't need an engineering degree to get a PPL... Fun part of this is watching these as a first year engineering student of a UAS in Europe...
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expectedThis from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
Cheers
At 12:20 you say "when we have air moving faster over the top of the wing". First of all why is there an assumption that air is moving faster over the top? Second: since top of the wing path is longer for your airfoil and air is moving faster over it, one would argue that time to travel those molecules you mentioned at 7:39 is indeed the same. So, there is a contradiction in your logic.
No contradiction at all.
It's not an assumption, we can directly observe it and measure the speeds all around a wing. The air starting in the same place that goes above a wing reaches the trailing edge *much sooner* than the air going under the wing.
..
See for yourself in this well known video: The non equal transit time (only) proof video by Holger Babinsky, Cambridge University
ua-cam.com/video/UqBmdZ-BNig/v-deo.html Narrated, no title at start Cambridge Univ.
This is a poor explanation in many ways. I just reposted my updated analysis of this video in the as its own comment.
Regards
> Second: since top of the wing path is longer for your airfoil and air is moving faster over it, one would argue that time to travel those molecules you mentioned at 7:39 is indeed the same.
Weak logic. You're making an (incorrect) inference that the delta is exactly that required to result in equal transit time when in fact at no point was that stated. Her diagram later in the video showed the top flow arriving at the trailing edge *before* the bottom.
So if equal transit theory is not true, why is airflow accelerated over the wing?
Bernoulli 'happens' in some regions around a wing, but the way it is commonly used is false and Bernoulli's Principle does not give the cause and effect at all, so it is a double fallacy.
. . .
The real reason the air above a wing speeds up toward the trailing edge is the decreasing Pressure Gradient from the leading edge to above the wing.
.
Speed does not cause a decrease in pressure.
Following up on Bernoulli's work in the mid 1700s, Euler determined that a Pressure Gradient in a region provides the force to accelerate fluid toward the lower pressure [because the higher pressure region pushes more than the lower pressure region.
.
The pressure decrease is because the flow is curved as it is directed over the leading edge. It would continue upward, but atmospheric pressure is still pushing downward. It doesn't go away when the wing starts moving.
The tendency to continue upward {Newton's First Law] works against that, thus reducing the pressure a small bit.
It is the very same as you feeling lighter at the top of a fast roller coaster hill - your body 'wants' to continue upward, thus working against gravity. .
Don't forget Newton's First Law. Inertia applies.
.
Following up on Bernoulli's work in the mid 1700s, Euler determined that it is a pressure difference between two locations, called a "pressure Gradient" that provides the force that Accelerates air toward the lower pressure - where that moving flow now assumes that lower pressure.
..
Bernoulli's Principle itself, refers to a speed INCREASE, which is acceleration, in a region being ACCOMPANIED BY a pressure decrease across the that SAME region. It does not say that one causes the other. It ONLY acknowledges the relationship. Per John D. Anderson's book, there is no indication that Bernoulli understood the cause and effect.
. . .
Thank you so much
It's really helpful ❤
I'm still pretty sure that the air over the top of the wing travels faster because it is displaced more than air under the bottom of the wing. And hence, faster air makes for lower pressure (Bernoulli) thus generating part of the total lift. Several factors contribute to lift. Perhaps the equal transit theory is just a way to illustrate Bernoulli's by comparing 2 air molecules, 1 above and 1 below the wing.
@@nitnisarge
Fine. But Bernoulli still applies because the air's flow is diverted by the angle of attack of the airfoil.
What happens when a plane flies upside down?
@@jameswalker3463
Same answer as for Nitin Tiwari, above, pretty much.
Upside down you can use the ailerons to create a camber on the airflow, or the tail surfaces to give you the angle of attack you want to give you lift.
This is Lecture 2, the straight and level part of the overall configuration of forces that you'll learn, assuming you're not just carping about something you already know, that is.
@@David_Lloyd-Jones A lot of the assumptions required for Bernoulli's equation is not valid in case of plane wings. Have a look: en.wikipedia.org/wiki/Bernoulli's_principle . Though you can say that it applies approximately but since it is not 100% correct you can't use it as an argument to explain lift. @James Walker when the plane flies upside down the lift acts in the opposite direction i.e. lift acts towards the ground (this will again depend on the wing configuration so it can't be generalized). A good example of negative lift being used is an upside down wing like shape used in F-1 cars to increase downforce and hence traction.
@@nitnisarge
When the plane is flying upside down, if the control surfaces (flaps, ailerons. slats...) remained unchanged, you would certainly be right. The "lift" would vector toward the ground.
This is not what happens. When the plane it turned over the pilot will change the positions of the ailerons etc. to change the camber of the whole airfoil and hence the flow of the air.
Change the bend in the wing by turning the flaps "up," i.e. toward the ground: you have Bernoulli operating in the opposite direction.
I'm curious: what do you think you see in the Wikipedia article that shows your " Bernoulli's equation is not valid in case of plane wings"?
Thank you
I would have liked to hear a better explanation of adverse yaw in an MIT aerodynamics class
if you were there you could have raised your hand ;)
Very basic information was presented.
Bernoulli's law is rarely taught correctly. Rarely does anyone point out the ambiguity in the equation: The equation merely states a link between fluid pressure and fluid speed, it does not tell you what causes what. A pressure difference between two points in space causes fluid to obtain speed between those two points. The speed of a fluid at a point in space does not cause the pressure seen at that point. Given a fluid speed at a point in space, Bernoulli's law is used to determine the pressure difference that creates that fluid speed. Likewise, given a pressure difference between two points in space...
Yes, it appears that Bernoulli is misinterpreted by the vast majority of mankind...
Then.
No equations show cause and effect, only the relationship of values.
A difference in pressure between two locations, called a Pressure Gradient, causes *acceleration* toward the lower pressure, NOT speed! A *change* in speed or velocity is acceleration.
If fluid is moving toward a higher pressure, the speed will decrease - a NEGATIVE acceleration.
@@Observ45er Fluid obtaining speed is acceleration. The speed of a fluid is brought about by acceleration. The point of my comment is to point out that teachers too often tell students that the change in speed or velocity of a fluid causes a change in pressure, which is an incorrect interpretation of the equation.
@@exilesurvivor1053 Precisely my point. So is fluid slowing and fluid flow curving.
People don't understand the science. Acceleration is also *any change* in velocity and many amateur scientists trying to explain this, as well intended they may be, don't understand and only repeat the wrong info.
Pressure Gradients CHANGE velocity (Acceleration), NOT cause increased speed.
People think acceleration is only "speeding up".
.
Watching a wing go by, you see THE *SAME accelerations,* but *different speeds*, so it is misleading to talk speed.
..
If you truly understand the science/physics, the fact that the air under the wing is faster, AS A WING PASSES YOU BY, will be no surprise to you..
Look at fig. 7 here:
rxesywwbdscllwpn.quora.com/
@@Observ45er Velocity is a measurement we invented that represents rate (speed) of something in terms of components of a coordinate system. Speed is simply magnitude of a velocity. In one dimensional motion, speed exists in only one dimension, thus speed and velocity are the same, or specifying the direction of the speed (velocity) is pointless. Even in two dimensional motion, the speed in one dimension may dominate. Pressure gradients DO increase the speed of a fluid. Air underneath a wing experiencing lift in the direction perpendicular to the upper surface is SLOWER than the air above the wing. The pressure above the wing becomes lower than the pressure below the wing because the orientation of the wing creates a void (relatively speaking) above the wing as the wing moves forward and displaces air molecules, and because air molecules under the wing collide with the wing surface and are deflected as the wing moves forward.
@@exilesurvivor1053 You have some ideas there that are understandably misleading.
.
Things can move only along a single path which for computational convenience, we separate into the three orthogonal component directions. You can say that we invented these three dimensions.
.
For motions, those are called components and they add vectorially. None “dominates”. It is simple vector addition and a larger component contributes more to the resultant direction and magnitude.
.
Speed is not a one dimensional only phenomenon. In curved movement the direction is constantly changing, therefore it cannot exist on only one dimension. It can have an instantaneous speed that must be in only one direction. However, because speed is a distance traveled over a time, the requirement of time in this quantity makes one dimensional speed meaningless..
.
Pressure Gradients Accelerate fluid and the direction of (positive) acceleration is the same as the direction of the force. F=MA is a vector equation where F and A are collinear.
.
Therefore, a force can increase the speed, decrease the speed, or change the direction of existent travel. These are all Acceleration.
.
Therefore, changing direction is not meaningless. A force with some component not colinear to the current direction of travel will change that direction over time and this is also acceleration.
When the direction of that force always points to a fixed location, this is called centripetal acceleration.
..
Above a wing, your ‘void’ (lower pressure) is caused by the air’s inertia/momentum trying to go straight and thus lowering the pressure toward the convex curve against the atmospheric pressure holding it to the surface. This forms the Pressure Gradient across the flow.
This lower pressure along with the relatively higher atmospheric pressure farther AHEAD of the wing accelerates air rearward, toward the trailing edge. ALSO, this lower pressure along with the relatively higher atmospheric pressure farther ABOVE the wing accelerates air downward joining (NOT re-joining) the lower air in the downwash behind the wing.
.. .. ..
Below AND above the wing, molecule are *always* 'colliding with the surface’. However, below the wing the inertia or momentum increases the pressure there and this *curves* the flow downward because the Pressure Gradient is across the flow giving centripetal acceleration.
.. .. .. .. .. ..
The under wing air is only slower from the wings frame of reference. Watching a wing go by in still air, measurements show the air under the wing is faster than the upper air.
Relative to the still air mass, the *under-wing air* is accelerated to a *higher speed* (magnitude) than the air above. (measured data shows this)
YET the accelerations observed in either view are the same and this is what needs to be understood about Bernoulli’s Principle.
.
Bernoulli’s Principle tells about pressures associated with *changes in velocity* which is acceleration, NOT simply increased speed.
..
The air exiting any blower into the atmosphere is at that SAME atmospheric pressure, not lower. The energy of the higher pressure air *INSIDE* the blower accelerated it into the relatively lower atmospheric pressure outside the blower.
... ... ... ...
Relating Bernoulli’s Principle to speed is one of the biggest myths held by amateur scientists that has persisted for a long time.
.
Please see these correct explanations of Bernoulli’s Principle and Lift.
rxesywwbdscllwpn.quora.com/
Regards
I have completed this for the 2021 class
good work. i watch this at 1.5 speed
I feel like she rushes through most topics without going into the details and ensuring actual understanding
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
@@Observ45erUr quite excellent in that analysis. I. Picked up most, almost all of what u highlighted too. Sometimes I wonder if these lectures got some high ranking, more experienced seniors to monitor what they actually teach the students. Coz such errors of omissions can determine whether a student fails or passes this course. And my man u qualify to be a senior supervisor above such lectures. Be blessed
@@kensimba7868 Thanks. She's supposed to have a advisor right there, also. Unfortunately, too many people don't really understand the physics.
.
I'm an experienced electrical engineer and took responsibility for a sophisticated flight simulator about 10 years ago. Since it had been years since I had ground school (I never went for the private license) and decided to brush up on some things because the students might ask any kind of question. I saw the three most common misconceptions about lift repeated over and over again. So I read some of the well known aerodynamics texts and even contacted a couple of the authors to discuss some of these things. One of my sons is an aeronautical engineer and he was very helpful in discussing a lot of this. My dad was also an engineer and he had this intense desire to understand things correctly and I guess I inherited it. He also had a private license that he got while learning to fly in biplanes, so I spent a fair amount of time in my youth around airports and other pilots.
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I've mentored others in the Navy and throughout my professional career and taught at two community colleges. If I'm going to explain something I'm going to understand it well first.
.
I have a Blog that gives the full physics for the fundamental concept of lift as well as the correct Bernoulli's principle:
rxesywwbdscllwpn DOT quora DOT com/
Cheers
The exact detail of how an aircraft flies is not projected well. There are some misleading issues in this video. Bernoulli does not explain some details appertaining to flying. In flying most issues can be explained through dynamic forces generated by mass being ACCELERATED and so that would be the RATE OF CHANGE OF MOMENTUM and not momentum.
Excellent presentation 🖒
Great Job!!!!!
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
At 37min 10 sec you mention the 4 forces but only name lift and weight. Either add thrust and drag, or omit mentioning the 4 forces,
I'm really surprised by the inconsistencies and lack of level of this presentation...
How so ?
MIT instructor talks about how she was going educate her students to greater levels than the FAA requrires, then goes on to refer to a "big jet engine with seats inside it " instead of saying "trasnport category aircraft >.
HERE FROM THE 2021 ZOOM CLASS
This video is fair and has some things ok and some thing wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
OK -- 6:12 Explains Equal transit, longer distance. Points to flat wing, same length. Math description not needed. Good Aeroastro graphics.
12:01 OOD Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD stationary pressures.
15:14 asks childish questions. Race Car.
16:36 Only says the spoiler “spoiles the air flow. Doesn’t explain that it has down lift.
18:09 Wing changes the speed of the air ALSO.
Never states that upper air beats lower air.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio withoug explaining it.
24:24 Mentions hand out car window and PUSHING, but dowsn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Comperssibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kitta Condition and says wrap around is an additional condidtion. 2D is simpler ) OK, but tip vortex in not true turbulence. So… Calculat where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between.
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This presentation is terrible, she starts talking about a subject without going in depth and just moves on whenever.
This is so cool
FAA sounds way more lenient and easy going than the EASA requirements.
I'm sure it's very hard to answer questions on the spot like this and I'm no physics major but not only are a lot of the answers and explanations incomplete in my opinion, this feels a lot like when you ask a teacher in high school something they don't understand and they try to over simplify in an obvious way. I liked this lecture but this isn't the standard I was expecting from MIT unfortunately.
Quick note: I don't believe she doesn't understand certain concepts, but teaching requires being able to explain concepts very clearly. Some could be the best at their job or skill but still not be able to teach it in the slightest.
I agree, and I think its because she's a private pilot, not a CFI. ie, not an expert. Seems like there's a bit of a gap between her expertise in another genre? of engineering and teaching. I'm studying for my CFI and am wondering how I will handle questions from students I have no idea how to answer.. 😂
@@dt10825 I think one of the best things to hear when someone doesnt know the answer is just for them to admit they don't fully know and that they'll find out. You can't expect a teacher to know everything but a good teacher wont try to fake an explanation but will do their research and have the answer for future students. Especially when it's a complicated subject which the student could have difficulty understanding by doing their own research.
Yes. unfortunately it's a plaguing issue in aviation across all levels and it causes accidents. There is a lingering fear of judgment and being called out within the aviation community. Something more important than knowing stuff is knowing how to reference the right materials.
Danny if in doubt always admit it and do some research, nothing wrong with learning as a CFI, I still try to learn as much as possible being a CFI.but there’s not point in feeding wrong information and ruining a students first experience to a subject, especially as this can this can cause miscommunication and lack of correct knowledge (primacy)!!
You're absolutely correct, Martin.
Ugh... the whole "horizontal component of lift turns the plane" description kills me.
well, that and aerodynamic stability
it gets kindof complicated
but in basis, it's not that incorrect
@@JulianDanzerHAL9001 Complicated for sure. My understanding is that the elevator turns the aircraft. Any "horizontal component of lift" will tend to push the plane sideways (translation) not turn it (torque.) You may get a little torque due to the vertical stabilizer causing some weathevaning, but up elevator pulls the nose through the turn. It is the most powerful torque arm in the system. I think the best tool is to imagine an aircraft with a symmetrical airfoil. There is no "horizontal component of lift" in a roll - all your lift is due to AoA, and all that AoA is due to elevator.
@@MatthewHarmon it's a combination of those
a horizontal component of lift changes the velocity of the plane, making it fly in adifferent direction
what actually turns the nose of the plane in that direction i a combination of rudder, elevator and aerodynamic stability
if you fly a several G turn i na jetfighter it's mostly elevator an daerodynamic stability
if you fly a regular turn in an airliner it's mostly rudder and aerodynamic stability
if you fly a turn without rudder it's urely aerodynamic stability - which is the easiest way to fly a turn though a bit uncomfortable
@@MatthewHarmon of course it depends on the type of plane
in a b2 bomber it's mostly differenctial airbrakes that turn the nose
and all these effects influence each other which then influnece each other back
@@MatthewHarmon Julian is correct.
You're confusing what controls are used and the forces. A curved path is an acceleration, no matter what the object. That force comes from the horizontal component of lift.
..
Maintaining the craft's orientation to the relative wind in order to maintain the turn, is done with the controls.
That very old mantra that the elevator turns the plane is only partly true because it also gets the AoA to simultaneously hold the airplane *UP* !
Since more total force is required to now support the plane AND supply sideways force, elevator is used to increase AoA for the needed increase in lift.
This is a prime example showing that pilots need to know how to control the craft and do not really need the deep science of all of it.
Chalk of color 😂🤣
paper airplanes don't fly, they glide.. :) Or, maybe I missed something, and pigs do fly. It could happen~ :)
Imagine working so hard to go to MIT only to find out you'd have learned more about flying from a cropduster in Kentucky.
mirrored window I disagree
@@ceguon9359 (comma because elaborative rationale)
you may have learend more from flying a cropduster... for years - than you will during th first half hour at mit...
but much of what you learn fro mflying a cropduster are probably misconceptions and simplifications that work half decently if flying a cropduster is all you want to do but are going to be catastrophic if you try to go into research or development and desing new airplanes
@@JulianDanzerHAL9001 great logic, except this is for flight instruction not engineering
@@dheujsnrhfydhehehshshhdggsd it's for flight instruction at mit
it's flight instructions
aimed at people who do both and thus need a deeper understanding of things as well
3:14
2020: Did she just say black board? Why not just say a board.
The only thing more annoying that people who bitch about not being PC... ...are people who bitch about people who bitch about not being PC.
@@saintmichael2759 Nah, joking about PC culture is just funny.
Weak
Am I the only one thinking that I'd love to give her a good seeing too on that desk.... 😂
I still believe in equal transit theory. You would never be able to prove this in a wind tunnel because the air is moving past the wing, but in real life, in the sky, your wing is moving through the air.
brotein she explained that earlier in the video. It's about point of reference. From the wing's point of view the air is moving past the wing, but from the air's point of view the wing is moving past the air.
Micah Person okay, well from one of those points of view I think equal transit theory makes sense.
Check out "The Secret of Flight" videos on UA-cam and you will see that the equal transit is a myth. Great wind tunnel videos.
@@macman603 it may well be that the "equal transit" theory is wrongly stated.. but even herself in her presentation stated when presenting Bernoulli'sLaw ( that is not a myth ) that the air on top goes indeed faster.. then reducing pressure and then the pressure differenctial creates lift..
otherwise since it is a longer distance if the air does not increases speed it should be creating either vacum.. or a lower density air area.. either way there will be less pressure on the longer way ( on top in this case..) so in content what the equal transit theory states is not really a mith.. the result is there to see..
and moreover.. it is a false that to create lift you need an angle of attack between the fluid and the foil shape.. you do if the shape is flat in both sides as is the case in a paper airplane wing but its proven hat a foil shape creates lift even without air 'hitting" the bottom... although that could add even more like for instance when an airplane is landing at low speed..
If she tells me it's false, I'm gonna look for a.second opinion. Good grief they want to learn to fly not hear about your thesis.
Its nice to know the "Why"
this is mit, not your backyard flightschool
so it's good for them to learn how and why things work, not just how to act with them while spreading misconceptions about the why
@@JulianDanzerHAL9001 mit huh? ua-cam.com/video/8ve23i5K334/v-deo.html do let us rubes let us know when they figure out a lightbulb
@@dheujsnrhfydhehehshshhdggsd when you didn't get to study science
but you also didn't get to study media literacy either
@@JulianDanzerHAL9001 you seem to confuse study with binge and purge. How's that lightbulb quandry going? Figure out where the wire goes yet?
Bullshit.Just read the book.
I thought it was a good lesson on aerodynamics
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
For real physics, see this: *rxesywwbdscllwpn.quora.com/*
For this video, here are the specifics:
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.
This video is fair and has some things ok and some things VERY wrong. It is nowhere near what should be expected from MIT. She is trying...
.
0:50 Vocabulary: doesn’t mention the vertical and horizontal “stabilizers”. Calls them “parts”. In the graphic, but not mentioned.
There is only ONE wing.
Going to talk about sea planes ???
3:11 initially says lift exceeds drag, but corrects it.
4:50 Draws an extreme airfoil shape.
5:22 The way she explains conservation of momentum is a good one, but momentum can be confusing to some people. It is not saying just how these pushes come about, but is better than just saying lift is a Third Law "reaction".
5: 30 Air has mass and conservation of momentum. Doesn’t explain how push occurs.
6:12 GOOD: Explains the Equal transit/longer distance fallacy. Points to flat wing, same length. Math description not needed - correct. Good Aeroastro graphics.
12:01 GOOD: Stated Bernoulli correctly using ‘velocity’. BUT focuses on fast.
12:40 "C" is the WRONG answer! The word "cause" is incorrect. "A" is the only correct statement there, but has nothing to do with Bernoulli..
12:42 The Graphic assigns INCORRECT cause to lower pressure.
14:00 GOOD: stationary pressures. She only mentions a "force" but not that it is pressures that cause the force!
15_24 Talking about the rest of the aircraft generating lift is a distraction and unnecessary.
15:57 Asks childish questions. Race Car.
16:36 Only says the spoiler “spoils the air flow. Doesn’t explain that it has down lift.
18:00 It is the altered pressures which cause the acceleration of the air (downward) ACCELERATION DOES NOT CAUSE THE FORECE !!!
18:09 Wing ALSO changes the speed of the air.
Never states that upper air beats lower air.
18:40 Air past wing, or wing past air question. The critical thing missed here is that the speeds are NOT "IDENTICAL", but different between these two reference frames, BUT the science must be the same. Therefore, talking about fast is misleading. It is ACCELERATION that must be understood.
18:54. Is wing moving faster through the air, or air moving faster past wing? Frame of reference discussion - SAME. Wind tunnel justification.
23:40 Mentions aspect ratio without explaining it.
24:24 Mentions hand out car window and PUSHING, but doesn’t relate to the - IGNORING the momentum explanation earlier.
25:28 Mentions Viscosity. Compares sticky. Sticks to the wing.
27:10 Compressibility affects lift in a different way. NOT FUNDAMENTALLY.
27:20 Calculating lift is not known.
29:45 CALCULATING LIFT. Mentions Kutta Condition and says wrap around is an additional condition. 2D is simpler ) OK, but tip vortex sn not true turbulence. So… Calculate where possible and measure elsewhere.
Doesn’t explain chord line. Says: “in between".
32:25 Talks about summing forces around the wing for lift, but doesn’t explain the top-bottom difference.
38:10 Doesn’t actually state what AoA is. Graphic shows it as “A” but is unnamed.
42:20 CONFUSED about the effect of flaps. Airspeed being higher with ground speed lower HUH??? Also doesn’t explain approach being steeper. Misses that is the increased lift that allows slower air speed.
47:38 Only explains that roll is around the longitudinal axis, but not the others.
48:13 Doesn’t explain why adverse yaw occurs.
48:15 Stability OK.
53:30 Question about what happens beyond the critical angle is not answered correctly. Lift does not go to zero. Did not demonstrate a paper airplane stall. It was too stable.
54:45 First mentions separation.
55:56 climb & decent, lift = weight.
57:15 Torque causes a left ROLL.
57:50 P-Factor not so much climbing because AoA not necessarily high, just on ground. They can’t answer the question at
1:02:20 Precession is 90 degrees later.
1:03:14 Question why P-factor not subject to precession. Sort of answered. It is a bigger factor on the ground for a tail dragger the ground where the ground prevents precession and in slow flight when precession only occurs during actual yaw.
In zero G flights confuses the upward parabola with top and downward parabola with bottom.