@@a_s_3.o try prof Suman chakrobarty videos for fluid ( available in UA-cam). I have watched all of them. Really good to build elementary level concept.
0:00 - 0:30. Introduction to Drag (What is drag ?) 0:50 - 1:05. Why is drag an unwanted force ? 1:30 - 2: 18 How is drag generated ? and formula for calculation of drag 2:19 - 2:31 Components of Drag force (Pressure drag and Friction drag ) 2:32 - 3:19 Pressure drag in detail 3:20 - 4:47 Flow separation in detail 4:48 - 5:00 Why do golf balls have dimples? ( Dimples increase turbulence and hence reduce flow separation. Reduced flow separation means less "pressure drag" and so the ball travels large distance). 5:01 - 7:15 Turbulence and its effects on Pressure drag and friction drag 7:17 : 8:05 Ridges on shark skin as bio inspired solution to reduce friction drag. 8:07 - 9:31 Effect of geometry and the orientation on Total drag. 9:32 : 9 :51 Quantification of drag force through integral approach. 9:52 Simplified formula for drag force. 9:53 - 10:11 The drag coefficient and how it's calculated. 10:22 - 10:36 The reference area (Emphasis on the selection of Area.) 10:37-12 :25 Re Vs Cd and arriving at stokes law. 12:26 -13:26 Arriving at terminal velocity of a sphere. 13:29-13:53 Constructing a Viscometer (In breif). 13:57-14:22 Components of drag forces of particular interest in aviation
I hope you enjoyed this look at aerodynamic drag! I'll be covering lift in the next video. ✈️ The bundle with CuriosityStream mentioned at the end of the video is no longer available - sign up directly to Nebula with this link to get the 40% discount! go.nebula.tv/theefficientengineer And here's a link to the extended version of this video - nebula.tv/videos/the-efficient-engineer-understanding-aerodynamic-drag-extended-version
This video is essentially a summary of chap 9 in the fluid mechanics book by Munson. I love how this channel explains these important topics with such simplicity. Keep up the good work.
I got so excited to see this on the feed, I was long waiting for a video about this. I started working on computational fluid dynamics half a year ago and it took me a lot of time to learn the theory behind it. You make everything look so easy to understand, you truly are a gifted teacher. Cheers!
The most intuitive and real physical explanation of all aerodynamic forces I can think of - is modification of static atmospheric pressure around an object due to air movement. Atmospheric pressure is defined by random bombardment of air molecules as per the kinetic theory of gases; this randomness is changed by the macroscopic air movement. As a result the pressure is modified around the object creating forces that we're labelling as drag and lift.
Wahh...! Solved many of my doubts regarding fluid mechanics in a single video. The best of best 👏👍. Engineers of our generation are blessed to have such sources. Thanks for providing such content and keep doing it.
Fluid mechanics is a deep subject. I feel like telling all businesses, employers and companies in America I have been totally psychologically destroyed. All people around me are perfect, and have perfectly economically secure lives. I feel miserable about not having a vehicle as well. My life feels about being isolated in total disempowerment. Do I need to see a psychiatrist to find out why I am isolated failure in America and among my relatives. I feel so bad every day, I want to get away from this location and be around some people that cannot torment me with failure.
brother, just watching the tutorial and thinking wow you put a good background music at such a level that helps the listener to concentrate many make it too loud to hear the speaker, great job.
I really enjoyed that you pointed out that pressure drag becomes more significant for blunt objects and friction drag becomes more significant for thin structures(and pipes I should add). This is something that isn't specifically mentioned in a lot of literature, but is an important intuition.
I watched this video more than five times completely, and each time I watch it, i understood this video better When i first watched it I had doubts like why turbulent flow delays boundary layer separation..why does flow separation cause dictate drag force..and how majestic is the graph at 11:44 I believe when I come back later, I would understand this video better.
I study high school with mechanical technical in Brazil and my teacher shared your video to my class. Your videos are really good, keep doing that!!! Sorry if i made a mistake in english, i'm still learning. Peace!
This video is very excellent - clearly highlighting all the key issues about drag, e.g. how adverse pressure gradient causes flow separation, how dimples on golf ball change boundary transition to delay flow separation and in turn reduce drag, etc. These are very important concepts!!!!
Yes Pedro is correct. By steepness I'm talking about how quickly the velocity changes as you move away from the surface. The change in velocity is more gradual for the laminar profile, and so the shear stress is lower.
For turbulent flow although velocity gradient is high and flow is unsteady, when we take statistical average it generally provides uniform profile unlike laminar where it gradually increases. Hence above velocity profile is correct.
Studying engineering and then watching this video = mind blown Theres always that missing piece of a puzzle. And for the study of fluid dynamics, I have no idea if humanity will keep unlocking all the secrets of the universe regarding this. I remember from a professor that told that a lot of these constants are found experimentally. I wonder if someday humanity can fully understand how these things are to a point where experimentation wont even be needed
This video is so amazingly great. For anyone looking to dig deeper, a very good book is "Introduction to Flight - John Anderson". It explains the math as elegantly as this video does and covers a whole whole lot more.
Fluid Mechanics All I learned from my previous study were solving maths problems only, my lecturer didn't explain the real examples such as golf ball, aeroplane wings, shark skin, etc and they are still getting high paid, Respect!!! That is why my country always poor, because they fail to educate and the cycle goes on.
A fun application of the terminal velocity is using a ping pong ball to determine altitude. To see whose rocket goes the highest, you eject a ping pong ball and time how long it takes to get to the ground.
I would recommend a brief explanation of Reynolds number. It is the ratio of the inertia forces to the viscous forces. A simple example is fill a coffee cup full of water. Very slowly tilt the cup. The water will run over the lip and down the side of the cup. This is because the viscous forces are keeping the water attached to the cup. No tilt the cup more until the water flows out of the cup and into a stream away from the cup. Now the inertia forces are dominate. Having said that, I found the video to be quite informative and accurate. (As an aerodynamicist I designed airplanes for nearly 40 years, mostly commercial but a few others tossed in for good measure and professional stimulation)
Lift induced drag simplified: Downwash tilts lift vector slightly backwards, lift vector backwards means that the lift is not only pulling upwards at the aircraft, but also backwards, which mimics drag. Downwash is caused by the shape of the airfoil and also caused or amplified by vortices.
Downwash is not caused by the shape of the airfoil. It is the result of the circulation generated to produce lift. L=rho* V*gamma) where gamma is the circulation strength.
From what I've read, shark-like roughness won't be advantageous for planes but mostly for boats and similar bluffer bodies, since the most of the gain comes from moving the curve Cd/Re in a way that makes the Cd to fall in the critical pit (the lower pit in the plot). Planes are obviously surrounded by a fully turbulent flow, so this would not be possible. It's the reason why golf balls have bumps while smaller/bigger balls are flat. Very nice video!
Riblets are another means of reducing turbulent friction drag. Riblets are microridges running in the direction of the local flow. The flow tends to sit on top of the ridges - the drag is reduced because the flow is not 'touching' the full wetted surface of the wehicle. As the video suggested, implementation is the issue - as well as how to maintain the integrity of the surface.
The Efficient Engineer alluded to asymmetric vortex shedding leading to instability but never went any further (at least not in this video) A good example of this is the baseball knuckleball. A pitcher throw the ball trying to not spin it. By not spinning, the laces do not trip the boundary layer. The flow separates somewhere on the ball and this sheds a vortex and causes a force imbalance. This shedding moves around the ball, the forces change and push in different directions, and thus the ball's flight path is erratic. The curve ball is just the opposite. The pitcher spins the ball rapidly so that the flow goes around one side more than the other. This produces a 'lift' (or sideforce) thus causing the ball to curve.
If the wing is moving forwards in stationary air space, the drag is the force required to ACCELERATE forwards mass of air near the wing.. If the air is moving in a wind tunnel with the wing stationary, the drag is the force required to DECELERATE the mass of air near the wing. ( parallel to the wing flight path) LIFT is created by ACCELERATING the air mass particles downwards ( orthogonal to the wing flight path) using compression effects below the wing and a partial vacuum effect above the wing.
Just finished my fluid mechanics course, this video sums everything up so elegantly. Love your videos!!!
69 likes. Perfection 👌
I failed that course 2 times in eng school 😂😂😂
This video is more useful than whole semester fluid course
True 😂😂👍.
It's the conclusion of our complete semester
That’s very unlikely 😂 what school do you go to
Exactly yAr..itne knowledge ke liye daily class,uske bad bhi concept clear nhi ho pata
@@a_s_3.o try prof Suman chakrobarty videos for fluid ( available in UA-cam). I have watched all of them. Really good to build elementary level concept.
Thanks,I love this vedio
0:00 - 0:30. Introduction to Drag (What is drag ?)
0:50 - 1:05. Why is drag an unwanted force ?
1:30 - 2: 18 How is drag generated ? and formula for calculation of drag
2:19 - 2:31 Components of Drag force (Pressure drag and Friction drag )
2:32 - 3:19 Pressure drag in detail
3:20 - 4:47 Flow separation in detail
4:48 - 5:00 Why do golf balls have dimples?
( Dimples increase turbulence and hence reduce flow separation. Reduced flow separation means less "pressure drag" and so the ball travels large distance).
5:01 - 7:15 Turbulence and its effects on Pressure drag and friction drag
7:17 : 8:05 Ridges on shark skin as bio inspired solution to reduce friction drag.
8:07 - 9:31 Effect of geometry and the orientation on Total drag.
9:32 : 9 :51 Quantification of drag force through integral approach.
9:52 Simplified formula for drag force.
9:53 - 10:11 The drag coefficient and how it's calculated.
10:22 - 10:36 The reference area (Emphasis on the selection of Area.)
10:37-12 :25 Re Vs Cd and arriving at stokes law.
12:26 -13:26 Arriving at terminal velocity of a sphere.
13:29-13:53 Constructing a Viscometer (In breif).
13:57-14:22 Components of drag forces of particular interest in aviation
Thank you :D
I hope you enjoyed this look at aerodynamic drag! I'll be covering lift in the next video.
✈️
The bundle with CuriosityStream mentioned at the end of the video is no longer available - sign up directly to Nebula with this link to get the 40% discount! go.nebula.tv/theefficientengineer
And here's a link to the extended version of this video - nebula.tv/videos/the-efficient-engineer-understanding-aerodynamic-drag-extended-version
Hi sir, what software applications used for animation
Thank you
please ....why hydrostatic forces exist in fluids and even in gases???
@@Bel...QWERTY1 due to the body force components ( eg :- due to gravity)
Once go through the hydrostatic law in fluid mechanics for better clarity
@@naveenkondeti5494 If it is due to gravity why or how it exists on vertical surfaces..??..i find it really hard to be understood im sorry
This video is essentially a summary of chap 9 in the fluid mechanics book by Munson. I love how this channel explains these important topics with such simplicity. Keep up the good work.
….simplicity? 😨 high school physics student here haha
You'll eventually get it bro. Everything happens on its time.@@Insomnia_tic
I got so excited to see this on the feed, I was long waiting for a video about this. I started working on computational fluid dynamics half a year ago and it took me a lot of time to learn the theory behind it. You make everything look so easy to understand, you truly are a gifted teacher. Cheers!
Atlast ...... A video on drag, the way you explain concepts is really amazing..... Please keep uploading more and also more frequently
Sup nigga?
@@GuruPrasad-qu4vg chat on UA-cam comments 😂😆
@@shauryagupta4990 small world
another gem of a video, keep up the great work you do!
The Efficient Engineer has actually encouraged us to prepare such videos because all videos in this channel are very descriptive and informative.
The most intuitive and real physical explanation of all aerodynamic forces I can think of - is modification of static atmospheric pressure around an object due to air movement. Atmospheric pressure is defined by random bombardment of air molecules as per the kinetic theory of gases; this randomness is changed by the macroscopic air movement. As a result the pressure is modified around the object creating forces that we're labelling as drag and lift.
Clear, concise, straight to the point, great illustrations, please keep doing those ! Hi from France !
Wahh...!
Solved many of my doubts regarding fluid mechanics in a single video. The best of best 👏👍.
Engineers of our generation are blessed to have such sources.
Thanks for providing such content and keep doing it.
Fluid mechanics is a deep subject. I feel like telling all businesses, employers and companies in America I have been totally psychologically destroyed. All people around me are perfect, and have perfectly economically secure lives. I feel miserable about not having a vehicle as well. My life feels about being isolated in total disempowerment. Do I need to see a psychiatrist to find out why I am isolated failure in America and among my relatives. I feel so bad every day, I want to get away from this location and be around some people that cannot torment me with failure.
Somehow you manage to cover the topics I'm coursing right now at Uni
Truly a gem of a channel
brother, just watching the tutorial and thinking wow you put a good background music at such a level that helps the listener to concentrate many make it too loud to hear the speaker, great job.
As I said it many times, I wish someone explained me these concepts as well as you do back in the days!
Mannnnn......why the hell do you explain so much gooooood.....you really explain clearly and hats off proud to the animation.....you the best
I really enjoyed that you pointed out that pressure drag becomes more significant for blunt objects and friction drag becomes more significant for thin structures(and pipes I should add). This is something that isn't specifically mentioned in a lot of literature, but is an important intuition.
This is not the first time you've managed to time your content with the same subjects I'm studying at the time , great video!
I was thinking about you from a while, I said to myself why didnt he uploaded something till the moment and here you are❤
I watched this video more than five times completely, and each time I watch it, i understood this video better
When i first watched it I had doubts like why turbulent flow delays boundary layer separation..why does flow separation cause dictate drag force..and how majestic is the graph at 11:44 I believe when I come back later, I would understand this video better.
These types of videos and people like you sir are the reason I still have hope I can truly understand what university professors poorly teach.
bro your videos is significant worth the time
Thanks mate, glad there're people like you making this kind of content! I really appreciate it!
Awesome, informative, and engaging video! Videos and channels like these will revolutionize education and learning for future engineers ❤️
One if the better explanations on this topic. Excellent work. Keep it up please!
Really great! It's so rare to find such simple analysis while being thoroughly! Keep it up. I really enjoyed your comprehensive language.
I study high school with mechanical technical in Brazil and my teacher shared your video to my class. Your videos are really good, keep doing that!!! Sorry if i made a mistake in english, i'm still learning. Peace!
Incredible way to explain so complicated concepts in a clear an intuitive way. Really good job!!! Subscribed for more content!!!!
This video is out just in time for my fluid mechanics course , thanx
Hi :)
Great video! Filled with lot of information. Keep posting. We just enjoying your way of creating video.
I am short of words to thank you for clarity of your explanations.
Thanks sir
You are a legend well done efficient engineer brilliantly explained
Never seen or found a video with this level of detail! It's so well explained, just amazing!! Congrats!!
This video is very excellent - clearly highlighting all the key issues about drag, e.g. how adverse pressure gradient causes flow separation, how dimples on golf ball change boundary transition to delay flow separation and in turn reduce drag, etc. These are very important concepts!!!!
Amazing tutorial 👍. Looks like whole fluid dynamics is discussed in single video. It Clears most of the doubt.
Every time I watched your content, it feels like I assist a course of 1 hour! It's really long, but interesting content! :)
@ 6:25 it should be steeper in laminar than in turbulent boundary layer. By the way, cheers to your work man👍
Yes i also think so pls correct me if i am wrong
Yes!
He is right because stress is proportional to dv/dy, so turbulent is steeper in reference to the y axis
Yes Pedro is correct. By steepness I'm talking about how quickly the velocity changes as you move away from the surface. The change in velocity is more gradual for the laminar profile, and so the shear stress is lower.
For turbulent flow although velocity gradient is high and flow is unsteady, when we take statistical average it generally provides uniform profile unlike laminar where it gradually increases. Hence above velocity profile is correct.
Studying engineering and then watching this video = mind blown
Theres always that missing piece of a puzzle. And for the study of fluid dynamics, I have no idea if humanity will keep unlocking all the secrets of the universe regarding this. I remember from a professor that told that a lot of these constants are found experimentally. I wonder if someday humanity can fully understand how these things are to a point where experimentation wont even be needed
I thought you have over 1 million subscribers. Your content quality is so awesome.
i'd just say..... you ought to get more than 316k subs bro. good job and keep up.
Hey man, you're a legend and your videos are sensational! ❤️
This helped me and my science partner a LOT Thank You!
Brilliant just brilliant!
Incredibly well explained! I honestly can't say how grateful I am for your videos, which really help for my engineering studies. Thank you so much!
Which branch you're studying
You guys doing very good job man. A civil engineer I appreciate it.
Brilliant Video as usual.👏👏 Always helpful, inspiring and motivational 🙌👏
Great video! I wish I had this at the start of my fluids course!
We did a viscometer experiment in a fluid dynamics course, we understood, but this explanation makes more intuitive and harder to forget
Took my fluids 1 exam yesterday. Damn, can wait to have fluids 2! Awesome content mate!
cant thank enough for these videos of yours! Waiting for more
this video is amazing
i've learned so much from this single video 😀
Very nicely explained and animated, great job as always!
This video is so amazingly great. For anyone looking to dig deeper, a very good book is "Introduction to Flight - John Anderson". It explains the math as elegantly as this video does and covers a whole whole lot more.
Thanks Fateen! I agree - Introduction to Flight is a great resource.
As usual great content that is supplemented by stunning visuals 👍
This is an amazing channel. Keep up the good work
This guy should have 1 M subscribers.
Another amazing video! Great work! Thank you!
Fluid Mechanics
All I learned from my previous study were solving maths problems only, my lecturer didn't explain the real examples such as golf ball, aeroplane wings, shark skin, etc
and they are still getting high paid, Respect!!!
That is why my country always poor, because they fail to educate and the cycle goes on.
A fun application of the terminal velocity is using a ping pong ball to determine altitude. To see whose rocket goes the highest, you eject a ping pong ball and time how long it takes to get to the ground.
Your all lectures are very useful for us thanks for making this video.🙏👍❤️
I was looking for an answer for a project and here you are!
Please continue series on aerodynamics ...your videos are just superb...i request you
I would recommend a brief explanation of Reynolds number. It is the ratio of the inertia forces to the viscous forces. A simple example is fill a coffee cup full of water. Very slowly tilt the cup. The water will run over the lip and down the side of the cup. This is because the viscous forces are keeping the water attached to the cup. No tilt the cup more until the water flows out of the cup and into a stream away from the cup. Now the inertia forces are dominate. Having said that, I found the video to be quite informative and accurate. (As an aerodynamicist I designed airplanes for nearly 40 years, mostly commercial but a few others tossed in for good measure and professional stimulation)
Man your work is just crazy, thanks a lot
Lift induced drag simplified: Downwash tilts lift vector slightly backwards, lift vector backwards means that the lift is not only pulling upwards at the aircraft, but also backwards, which mimics drag. Downwash is caused by the shape of the airfoil and also caused or amplified by vortices.
Downwash is not caused by the shape of the airfoil. It is the result of the circulation generated to produce lift. L=rho* V*gamma) where gamma is the circulation strength.
This is brilliant! Congrats
You are the best, you are the absolute best.
No wonder why your video takes large time🤟🤟🤟🤟🤟
Amazing channel, so glad I found it!
Excellent video. Thanks for the very well explained video.
What a legend man❤️
Helped a lot
Thank you for the perfect job. Very well done!
From what I've read, shark-like roughness won't be advantageous for planes but mostly for boats and similar bluffer bodies, since the most of the gain comes from moving the curve Cd/Re in a way that makes the Cd to fall in the critical pit (the lower pit in the plot). Planes are obviously surrounded by a fully turbulent flow, so this would not be possible. It's the reason why golf balls have bumps while smaller/bigger balls are flat. Very nice video!
Riblets are another means of reducing turbulent friction drag. Riblets are microridges running in the direction of the local flow. The flow tends to sit on top of the ridges - the drag is reduced because the flow is not 'touching' the full wetted surface of the wehicle. As the video suggested, implementation is the issue - as well as how to maintain the integrity of the surface.
I am an aeronautical engineer. This video is spot on.
Really and informative video with clear concepts. Thanks
Your channel is wonderful!
Most beautiful explanation on aerodynamics ever...👍🙏👌👌👌👌👌👌
The Efficient Engineer alluded to asymmetric vortex shedding leading to instability but never went any further (at least not in this video) A good example of this is the baseball knuckleball. A pitcher throw the ball trying to not spin it. By not spinning, the laces do not trip the boundary layer. The flow separates somewhere on the ball and this sheds a vortex and causes a force imbalance. This shedding moves around the ball, the forces change and push in different directions, and thus the ball's flight path is erratic. The curve ball is just the opposite. The pitcher spins the ball rapidly so that the flow goes around one side more than the other. This produces a 'lift' (or sideforce) thus causing the ball to curve.
You are revolutionizing education!! Keep it up! Thanks a lot
Great work man .....
It's my humble request plz plz upload videos more often
You will go far. Thank you for helping me with static.
It was awesome.
Very nice 👌
Looking up to you for more Aerospace content.
finally
love you man
please upload more videos on structural anlysis please
7:18 Shark skin
8:05 Shape of body and angle of attack, plate
9:08 Friction, pressure, and total drag on graph
11:45 Stoke's Law
Keep doing this great work.
Very good explanation, thanks!
you explain these brilliant way❤ there are more complicated to understand lecture note😢
Thanks man such a wonderful video
your videos are astounding
damn these animations are top notch
Oh gosh how is so conceptually clear !
Amazing helped a lot to understand from scrach
My best lecture ever
Many thanks sir
This video was anything but a drag!
Absolutely brilliant explanation! 💯👍
ohh you are back, nice to see you again ^_^
My friend, I hope you are making money, because you deserve it.
This is art
this 16 minutes video was more helpfull then the 2 hours i spent trying to understand the drag chapter from the principles of flight manual
Love this channel
If the wing is moving forwards in stationary air space, the drag is the force required to ACCELERATE forwards mass of air near the wing..
If the air is moving in a wind tunnel with the wing stationary, the drag is the force required to DECELERATE the mass of air near the wing.
( parallel to the wing flight path)
LIFT is created by ACCELERATING the air mass particles downwards ( orthogonal to the wing flight path) using compression effects below the wing and a partial vacuum effect above the wing.