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Awesome

Great explanation to bring a very complex topic. From engineering /mathematical point of view, I recommend Kutta-Jokowski Circulation Theory from the beginning of thee 20th century and the derived airfoil theories, as well the tons of experiments by NACA on the origins of the Aeronautical Studies to determine Polars of Lift and Drag coefficients vs. Angle of Attack. Fluid mechanics can support also on the understanding of concepts such as the 'limit layer', laminar and turbulent flows as well transition zones to get a full picture on the generation of local pressure zones.

Three wise men were responsible for "inventing" the lifting power of the wing. The first and most important is Newton with his laws of mass changing direction. Then we have Coanda who helps Newton with what happens to mass following a curve on the upper side of a wing. Finally, we have Bernoulli who says he is in on it all because the wing is somehow sucked up by a magical negative pressure above the wing, but this effect cannot be proven.

Put your hand outside of a car window.

IF curvature is the answer for lift, then how does a flat wing generate lift? I sort of know the answer but the Prof should have touched on the flat wing because another prof might do a whole video on flat wings or symmetrical. I believe the answer to my own question is something to do with angle of attack and Newtons 3rd law 😮

Lecture is from 2003. If you want to know how planes fly here is the dude to listen to; NOT NdGT! 😎

We equals mine

Now ya know

will the coanda effect work in a vacuum? if yes why?

Therefore, while the promise of entering his rest still stands, let us fear lest any of you should seem to have failed to reach it. For good news came to us just as to them, but the message they heard did not benefit them, because they were not united by faith with those who listened. although his works were finished from the foundation of the world. Hebrews 4 . Jesus answered them, “This is the work of God, that you believe in him whom he has sent.” John 6 . faith enters in the finished work and finds rest

Great simple presentation of a complex matter. Well done!

So, the lift could be explained without using Bernoulli and only by Coanda effect?

Brilliant explanation indeed! Congrats 🎉

This is just the ramblings of a man who has been in the theoretical side of things for too long. There is a reason why aircraft tend to require a large velocity in flight.

The amount of "we don't need to worry about that"s concern me.

He looks happy enough in the thumbnail, I don't think he need s a lift.

39:05 I don't agree, when you pour a liquid and some of it runs down the side of the container is because of adhesion. If it was the coanda effect, it would increase when pouring faster.

WOW, I have been an airline pilot fo 40 years, and I finally get it!

air go down plane go up Considering the big picture, is Newton's perspective sufficient?

try to blow in between 2 pieces of papers that are vertical and parallel, close to each other see what happens

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Sorry prof but you have got it wrong. When you blew across the flat paper the paper it did not move towards the faster flowing air because the energy to accelerate the air came from you not the surrounding air so the air pressure did not fall. Bernoulli’s theorem states that the acceleration of the air is a transfer of energy from the surrounding air. Which is why the pressure falls. Bernoulli’s theory explains flight.

The Christians taught by the Apostles believed in the true presence of Christ in the Eucharist. This guy read a Bible, then made up what he wanted it to mean.

glad i heardsiseltalkabout where this had comefrom;;;;

I'm 15 years and English isn't my first language, but I understood every word. Professor is explanating really simple and easy to understand

The sail example is bullsh*t. Who says the wind flows at an equal speed over the sail? Also, everyone now knows that the air over the top of the wing moves faster than the air over the bottom of the wing. Increased dynamic pressure means decreased static pressure. hence lift d*ckhead. Bernoulli also doesn’t say anything about a constant, rather that Pstatic x Pdynamic = Ptotal.

all the paper airplanes i made as a kid disagree with you

there is not much of a curve to an f104's wing!!! - i wonder if the principals change above mach1

Babinsky is wrong. It is not the curvature that causes the low pressure. The streamlines are curved to navigate the physical object in the flow, each streamline formed by the mass boundary of surrounding streamlines, since the flow is incompressible. Streamlines are constricted in x section thickness due to the physical obstruction of the solid wing, thus by Bernoulli, streams have increased velocity and dynamic pressure, and this is what causes the low pressure. In theory, this would mean the streamlines under the wing would have high dynamic pressure and low static pressure as well, and by C effect turn around the trailing edge of the wing onto the upper surface of the wing where the rear stagnation point of the flow around the wing should be. In theory, resulting in zero lift. However, due to viscousity of the fluid, boundary layer seperation occurs very soon after the BL navigates around the sharp trailing edge, changing the flow geometry. This effect is same as having a vortex around the aerofoil, or as demostrated, a cylinder spinning. The reaction to this vortex is a torque opposite to the angle of attack acting on the wing. This is the ONLY action reaction pair in the system! The flow under the wing wants to turn around the trailing edge, but is forced to carry on in the observed geometry under the influence of the vortex generated by the wing. As a result, once stable flow is achieved, the under wing streamlines are far less restricted in x section thickness and have high static pressure. This is the real way lift is created. The fat wing has a weaker vortex because its trailing edge is less sharp

Babinsky is wrong, there is a constant for Bernoulli in a system open to the atmosphere: it is atmospheric pressure. The flow generated by the hairdryer has kinetic energy, but its total pressure is still atmospheric pressure. Static pressure inside the flow is much lower than atmospheric pressure. This is how carburetors work.

Babinsky is wrong. A streamline is flow restricted that particular path by conditions and forces external to that streamline. Curvature does not generate low pressure, the C effect is because a solid surface has no pressure. You can tell an explanation or a path of reasoning is suspect if the phrase "there must be" gets thrown around, it is a statement of speculation

Babinsky is wrong. About the curvature and the blowing paper demonstration. The reason why the paper doesnt move in the vertical scenario is because the paper is already in contact with the stream. Repeat the demonstration with perfectly flat paper and a fan, and different angles with respect to starting angle of the flat paper and the paper will always lift towards the boundary of the moving airstream until in contact with the stream

How does your explanation distinguish between the flow around a hydrofoil in liquid helium compared to the same hydrofoil in liquid sodium with identical geometry or kinematics?

(15:17) By hanging the sheet of paper vertically, the downward STATIC pressure gradient due to GRAVITY is no longer providing that differential in pressure on the ground facing side of a horizontal planal surface. Gravity's effect on a fluid like air is the prerequisite of lift !! How counterintuitive. (46:30) By the same reasoning, wouldn't the thicker aerofoil would generate less lift in this airstream profile because the convex bottom surface is accelerating the airflow a neutralizing the effect of the contrast in pressure between upper and lower surfaces if the aerofoil? Ah, paragliders, of course. (54:00) The spinning ball in the airstream. American baseball pitchers take advantage of this aerodynamic effect to keep batters from any contact on the baseballs that are hurled toward home plate.

Since my original comment below, another thought has struck me: Prof Babinski makes a point of neglecting friction in his explanation of the generation of lift. However, do I recall being taught (and reading in the various books, which I have collected over the years, in order to arrive at an understanding of lift) that, in an inviscid flow, where there can be no drag, there can also be no lift? Prof Babinski demonstrated the generation of lift by a rotating cylinder (the Magnus effect) in his little vertical wind tunnel. However, a rotating cylinder (or spinning football) clearly relies on friction to create the asymmetric flow condition. Should he not have addressed this?

The authors have two wrong scientific approaches: researching the creation of Lift force and Low pressure at upper side of the wing, relative to the ground surface and Earth. I explain the aerodynamic cavitation and existence of Lee side aerocavern, and creation of Aerodynamic force.

Nice explanation sir

46:00 minutes Very nice demonstration of the common bernoulli explanation. On the left we have a fat low resistance foil, and on the left we have a foil that has much more resistance. So, the greater the differential I'm resistance between top and bottom then the greater the flow speed differential and the greater the pressure differential.

He is wrong.

Garbage.. totally overlooked shear forces and their gradient due to boundary layer, across the finite fluid cube R8 approach is treat airfoil as 1/2 venturi & use velocity gradient within boundary layer to model pressure drop at top surfaces v bottom surface

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I can make a working perpetual motion machine

14:22 His debunking of the photocopier paper experiment is itself bunk. When he holds it down, he tensions the paper in such a way that the Bernoulli effect can't work it. It might have just as well been a sheet of cardboard. If you hold a sheet of paper vertical to the earth (from which most gravity comes) and allow it enough flexibility to sway, then the experiment proves Bernoulli. As the forced air stream moves downward, it entrains higher pressure air into the flow on the non-paper side of the stream. On the paper side of the stream, it cannot entrain the adjacent air into the stream flow because the paper is blocking the air from entraining, so it pulls the paper itself. Then in the next second, the entrained flow on the non-paper side mixes into the stream and increases the pressure there. That should lower the difference between pressure in the stream and pressure around the stream, except that the paper blocks the air on its side of the stream from entraining into the flow, and so the force pulling the paper persists. Add some aluminum, kerosene, and human ingenuity, and you have an A380. Give it a fair try it yourself.

Errata?: Cows are blown UP just outside the low pressure eye of violent spiralling winds, according to Researchers with Cameras. More to do with tangential momentum and Ground Effect than "suction", they say?

The "Rubber Sheet" explanation of Gravity using Gravity = Negative Lift, is a similar pattern of discovery of a specific Form in Function, by "design" = frequency density-intensity alignment of "conducting" resonance-location cofactors in prime superposition, ie "Form follows Function" and e-Pi-i sync-duration connectivity function operates on itself, "module-ates", self-defining Real-time Number substantiation. A consequence of this proof-disproof in Theoretical Design Testing, is that the explanation of Observable Actuality Conception is the reference-framing pure-math relative-timing ratio-rates-> Circuitry of QM-TIME, instantaneous "creation" condensation-quantization = Quantum pure-math-fields oscillation, ..axial-tangential @.dt zero-infinity orthogonality sync-duration, for superposition resonances-> net vector-values temporal superposition apparent "flow", and the cause-effect omnidirectional-dimensional information-pressure, which is Fractal Quantum Operator Logic Fields Modulation Mechanism, ..at the Centre of Time Duration Timing Singularity.., aka Inflation, Gravity, line-of-sight frequency superposition, because frequency aligned-> Cofactor Conduction, radial projection-drawing holographic phenomena such as density-intensity real-numberness condensation modulation matter, and so on. Reciproction-recirculation Singularity synthesises an AM-FM holographic 0-1-2-ness 3D-T pictorial image, by e-Pi-i log-antilog interference.., so => allowing the Rubber Sheet to represent the plasticity of functional-temporal logarithmic hyperfluid vertices in vortices, lifted = floating or levitating, apparently on nothing, actually embedded in Superspin-foam Temporal Totality. Putting things in perspective, 0-1-2-ness line-of-sight Fluxion-Integral superposition =i-reflection on the picture-plane projection-drawing image containment.., makes the balanced orthogonal-normal pure-math relative-timing ratio-rates Equation in the Holographic Principle Imagery, a bit more interesting. Especially if you begin with the Calculus of Logarithmic Time Condensation Communication here-now-forever. Resonance is a very simple concept to grasp Mathematically-Musically, in a fractal AM-FM conic-cyclonic Centre of Time Duration Timing Conception way..

As an engineer with a lifelong interest in flight, I'd puzzled over how a wing really worked for years. Then, some years ago, came up with a hypothesis with which I was satisfied - only to discover that Prof Babinsky had beaten me to it! However, I have one issue that even Prof Babinsky and many others fail to addresss. Lift is explained in terms of moving air flowing over a stationary wing, as in a wind tunnel. However, that is not what happens in the 'real world', where a moving aerofoil displaces previously stationary air. We need a 'real world' model of this, showing the downward displacement of air after the passage of a wing, which must also have a small forward component. For a 'real world' example, please take a look at any one of several photos or videos of aircraft flying just above the cloud tops.

The illustration of the sailboat is incorrect as any sailor can tell you. The air does does not flow over the leeward side of the sail the same way as the windward side. If it did, the sail would merely flap as it does when you head directly into the wind. When the sail is full and trimmed, there are eddies of air close to the leading edge (behind the mast) and the wind rushes over the eddies like it does a wing. You can see this on a sail that has "telltales" (short 6-8 inch pieces of wool yarn) attached to the sail a few feet above the boom in a line from the belly (near the mast) to the leach (the trailing edge) of the sail. The one near the mast will be fluttering all over and sometimes be pointing straight up the sail at twelve o'clock. The rest will hang at progressively higher angles from the vertical to horizontal (6 o'clock to 3 o'clock) as they approach the trailing edge, with the one on the edge streaming straight out to 3 o'clock as you would expect. In fact, a good helmsman will steer and trim the sails watching the telltales to get the most speed out of the boat.

Glory a God.so beautiful🙏🙏🙏

Awesome, all my respect

This still does not explain how a paper plane flys which have completely flat wings, any help??