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Dynamics Uci
Приєднався 29 вер 2017
Відео
History of the Theory of Lift: A Mathematical War in the Background of the Great War (Part II)
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When the Wright brothers made their historic record in December 1903 of the first powered flight, there was no workable theory of lift. Even the most basic question in aeronautics on how much lift a wing produces could not be answered in a principled way. The Wrights had simply built their airplane by trial-and-error. The emergence of this new machine (the airplane) posed danger to countries in...
History of the Theory of Lift: A Mathematical War in the Background of the Great War (Part I)
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When the Wright brothers made their historic record in December 1903 of the first powered flight, there was no workable theory of lift. Even the most basic question in aeronautics on how much lift a wing produces could not be answered in a principled way. The Wrights had simply built their airplane by trial-and-error. The emergence of this new machine (the airplane) posed danger to countries in...
A New Theory of Lift
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In this paper we revive a special, less-common, variational principle in analytical mechanics (Hertz’ principle of least curvature) to develop a novel variational analogue of Euler's equations for the dynamics of an ideal fluid. The new variational formulation is fundamentally different from those formulations based on Hamilton's principle of least action. Using this new variational formulation...
Vibrational Control in Insect Flight
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Vibrational Control in Insect Flight
History of Aerodynamics II: The Science that Enabled Flight
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History of Aerodynamics II: The Science that Enabled Flight
History of Fluid Mechanics I: From Archimedes to Stokes
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History of Fluid Mechanics I: From Archimedes to Stokes
Lecture 13. Session II: Principle of Least Action (Fall 2019) Part 4
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Lecture 13. Session II: Principle of Least Action (Fall 2019) Part 4
Lecture 13. History of the Principle of Least Action Part 3
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Lecture 13. History of the Principle of Least Action Part 3
Lecture 13. History of the Principle of Least Action Part 2
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Lecture 13. History of the Principle of Least Action Part 2
is the lecture notes still available?
I googled "inverted pendulum" and then "Kapitza's pendulum" after reading xkcd 2924
Starts 2:39
I would submit that the least curvature is surrogate for least drag. The shape of the wing is all about minimizing drag. You might get some lift from the curvature, but lift derives mostly from the angle of attack. And I don’t get how this insight explains why thicker shaped airfoils are needed at slow speed, whereas minimizing drag does.
One of the best lectures i have ever seen. Much energy and passion. Thank you very much.
Hi professor, i have question about all movable v-tail configuration. I tried to write dynamic equations for it but i couldn't. I there any book or material i can use as reference. Is there any effect of dihedral angle on equations?
Thanks for everything Sir. How can we reach the lecture pdf?
Excellent lecture! omg. I loved it. It helped me understand concepts in a new way!
May, i have your email id please
Come form 2023 Nobel Physics Prize advanced background document too, this interesting phenomenon seems to reveal how a rapid process can affect a normal thing.
I just had to watch this after reading Nobel Physics 2023 background paper.
Come from the “Nobel Prize” paper | 2023 Your famous now 🫱🏻🫲🏼
Thank you , truly enjoyed listening to this.
Great Presentation
One could argue the variational theory of lift still would not have satisfied the British school, for variational principles appeal most to those with hearts of engineers.
On the contrary, variational principles are most common among mathematical physicists, which is the main characteristic of the British School.
على فكرة يادكتور موضوع تاريخ الطيران ده ينفع يتعمل كتاب شيق جدا ومبسط للمكتبة العربية, لانه يستهدف القارئ العادي يعني قارئ في مستوى طالب ثانوي
I watched your videos on nonlinear geometric control and found them very fantastic (great explanation). I hope you will do videos on calculus of variation.
Very nice!
Very informative video! Thank you.
Here is the (corrected!) citation for the paper: Gonzalez, C., & Taha, H. (2022). A variational theory of lift. Journal of Fluid Mechanics, 941, A58. doi:10.1017/jfm.2022.348
Many thanks Dr. Haithem for these couple lectures, you can not imagine how this kind of lecture can improve the learning experience. I think these lectures are so important for undergraduates in advance or after finishing their fluid dynamics courses to link all separate theories together. Again many thanks for your effort.
Thank you Ahmed.
First of all, thank you so much for sharing these lectures! This is such an invaluable lecture series! I'm very grateful! Request/Question: Could we get access to the "online" lectures somewhere? specially curious about the application to concept of nonholonomic constraints mentioned in the video.
I don't think he's a good teacher, you can't be introducing an obscure course like this to first time students with this poor teaching skills!
I couldn't watch more than 3 minutes of this rubbish. Lift is one component of the aerodynamic force. The aerodynamic force comes from pressure differences in the air. The origin of the pressure differences is explained in the paper linked in the description ua-cam.com/video/dgE9xhIjTOU/v-deo.html
These were a fun pair of lectures. Thank you for putting together this summary of the history of Lift.
mükemmel anlatım burdan mesut uyanerinn ben aw
Ağzına sağlık be kardeşim
18:52 also assume e is 3, pi is 3, 4 is 3, g is pi squared... all gases are ideal, all flows are laminar and incompressibility is a myth 😆
Why is g so close to pi squared ? What is pi squared? It is 6*(1+1/2^2+1/3^2+....) What is g ? It is GM/R^2 or sum(Gm/r^2)=G*sum(m/r^2) What are M & m?M = Earth's total mass & m = density * volume . Density is a function of position inside Earth's bulk. Should be possible to derive g using this info, vector calculus & integration. - I did this and it works out with some assumptions, but it's easier to use the method in the comment below to get pi squared.
You can also thank the French Republic for the fact that g is about pi squared. BY DEFINITION: "shortest distance from the North Pole to the equator passing through Paris" = 10^7 [mètre étalons] , where R= Earth's radius in mètre étalons. This is assuming an Earth flattening of f=1/334=1-b/a, which is pretty negligible [a=12732 km]. So, this will be pi* R/2 on a spherical Earth or roughly pi*sqrt(a^2+b^2)/4=(pi/4)*a*sqrt(1+f^2) on an ellipsoid. With the French Revolution of 1789, the desire to unify measures and to free itself from the heritage of the Ancien Régime was affirmed . The meter is adopted and its definition refined as being the ten-millionth part of the meridian passing through Paris and connecting the North Pole to the Equator . This distance is extrapolated from the measurement of the meridian arc connecting Dunkirk to Barcelona based on a flattening of 1/334. The meter is kept in Paris in the form of a platinum standard, the Archives Meter. In 1889, it was replaced at the initiative of the International Geodesic Association by thirty international prototypes distributed throughout the world. The comparison of these platinum-iridium standards with each other and with the Archives Meter involves the development of special measuring instruments and the definition of a reproducible temperature scale. - Histoire_du_mètre| wiki Assuming a spherical Earth, with flattening =0, pi * R /2 =10^7 [metres]. Consequently: GM/R^2=GM/((2/pi)*10^7)^2=GM(pi^2)/(4*10^14)~pi^2. It turns out that GM is about 39.86*10^13 ~ 4*10^14 [m^3 s^-2], which is why this works out. "The task of coming up with a new system of measurement was given to the nation’s preeminent scientific thinkers of the Enlightenment. These scientists were keen to create a new, uniform set based on reason rather than local authorities and traditions. Therefore, it was determined that the metre was to be based purely on nature. It was to be one 10-millionth of the distance from the North Pole to the equator. The line of longitude running from the pole to the equator that would be used to determine the length of the new standard was the Paris meridian. This line bisects the centre of the Paris Observatory building in the 14th arrondissement, and is marked by a brass strip laid into the white marble floor of its high-ceilinged Meridian Room, or Cassini Room. Although the Paris Observatory is not currently open to the public, you can trace the meridian line through the city by looking out for small bronze disks on the ground with the word ARAGO on them, installed by Dutch artist Jan Dibbets in 1994 as a memorial to the French astronomer François Arago. This is the line that two astronomers set out from Paris to measure in 1792. Jean-Baptiste-Joseph Delambre travelled north to Dunkirk while Pierre Méchain travelled south to Barcelona. Using the latest equipment and the mathematical process of triangulation to measure the meridian arc between these two sea-level locations, and then extrapolating the distance between the North Pole and the equator by extending the arc to an ellipse, the two astronomers aimed to meet back in Paris to come up with the new, universal standard of measurement within one year. It ended up taking seven." - By Madhvi Ramani, 24th September 2018 | BBC travel website.
Very informative lecture professor. Warm Regards from Pakistan
08:45 "Lie Bracket, the most useful entity in this course, we will be using it OVER AND OVER AGAIN" =)=)
goat
Lecture 13 has 3 redundant videos.
No, lecture 13 has two different versions: one on technical material whose part I is the following: ua-cam.com/video/-k1Xx-Lpj9w/v-deo.html and another on the history of the principle of least action whose part I is this video.
The last 6 videos are redundant?
6:02 Mentioned in lecture 13
This still doesn't tell us how to obtain the magic formulation in ua-cam.com/video/a1yb1QB41wA/v-deo.html
2:00 Why does Phi(0) comprise the vectors X_1(0), ..., X_n(0)?
I need this professor's email
I need this professor's email
Wow thank you so much!
10:11 Also mentioned in ua-cam.com/video/kNiQv52hZZk/v-deo.html
??? lmao these you guys seem to be Oblivious to the observable fact that, a thin trailing edge makes Less drag than a thick one.!!! for OBVIOUS reasons.
There is something about this guy that reminds me of the eggs between two legs. 😂😂
What about the Newtonian explanation of lift? Newton explains why lift quadruples when aircraft velocity doubles. ua-cam.com/video/lSRA3KG74bg/v-deo.html
0:56 First introduced here: ua-cam.com/video/0Nfbqt6TI7g/v-deo.html
16:18 Why are we able to ignore all other coefficients (e.g. X^2, Y^2, YX)?
They are not needed. We need 3 independent equations for h1, h2, and h3, which were already obtained. Any other equations will not be new equations. For example the X^2 equation is h1 h1dot = h1 v1, which is simply the first equation multiplied by h1.
7:55 did you mean without multiplicative inverse? Is a ring without a multiplicative identity still a ring?
Check the following links: 1) en.wikipedia.org/wiki/Ring_(mathematics) 2) en.wikipedia.org/wiki/Lie_bracket_of_vector_fields Multiplicative inverses need not exist of rings.
14:12 It seems to be missing the summation over i, according to ua-cam.com/video/dWVBQ9dJHqk/v-deo.html
It is wrong approach researching the creation of Lift force and Low pressure at upper side of the wing. I explain the aerodynamic cavitation and existence of Lee side aerocavern, and creation of Aerodynamic force.
There NO Lift `force` and NO Drag `force`, it is Aerodynamic force. Lift and Drag are just components in coordinate system.
I only know that I know nothing
Congratulations guys, very interesting finding!
Do you have a very dumbed down version of this video for pilots?
A feast