Відео

If wings could actually create a net acceleration of air, they'd create thrust.

​@@user-do5zk6jh1k a) Babinsky says they do and b) I don't think the video shows that, so how does your reply relate to my comment?

@@RationalDiscourse Let me tell you straight. You don't understand what you're looking at, and you forgot what you wrote 5 months ago. You shouldn't be surprised that the freestream airflow is outpacing the upper surface flow. If it were the other way around, the upper surface would be creating thrust.

has it been widespread yet? under what name? because i can't find it anywhere, and it seems like a very helpful tech so its weird if its not sold yet

You might find this an interesting read: www.eng.cam.ac.uk/news/enigma-code-breaking-machine-rebuilt-cambridge

Nein

This MPhil programme might interest you: www.postgraduate.study.cam.ac.uk/courses/directory/egegmpmsl

NOOOOOO, stay in INDIA!!!!!!!!

@@BlueSkiesAbove39 Lol, how do you if I'm in India? 😂 I live in UK 🤣🤣🤣🤣🤣🤣

@@BlueSkiesAbove39 Then why would you say that? I'm not an Indian instead a random human on a planet called "EARTH".

Can you post a link or reference to those experiments? My supplies of liquid helium and liquid sodium are running a bit low.

@@alans172 I'm making predictions. In liquid helium vorticity is quantised. A very slow hydrofoil will be below the quantum level and no starting vortex is produced. No starting vortex means equal transit time has to be true, but there is no net lift.

@@david_porthouse The essence of a thought experiment (c.f. Einstein's gedankenexperiment) is that it can be imagined.

@@alans172 What can also be imagined in two dimensions is a quantised vortex in Brownian motion with the quantum and the kinematic viscosity having the same value. That's an entity which is arguably both a wave and a particle.

@@david_porthouse Ha ha! And I thought for a moment you were trying to be serious. Nice one!

Air resistance causing deformation causing more air resistance. It's the same as trying to balance an egg on its top, unstable equilibrium.

The air stream closest to the upper surface of the wing has traveled a longer distance than the stream at the top of your screen. Yes they reach the trailing edge at the same time, however the stream just above the wing had to curve around the wing a travel farther in the same amount of time. Imagine those lines are strings and if you were to pull the string closest to the surface of the wing tight, it would extend farther than the rest of the strings.

@@rileybullen4961 The smoke over the top of the wing arrives at the trailing edge AFTER the smoke the top of the screen. Pause the video at 0:47 where the smoke above the wing is nearly at the trailing edge. The smoke at the top of the screen has already passed the trailing edge. Take another cool hard look at that frame. They do not arrive simultaneously!

The airflow that is squeezed between the foil and atmospheric pressure , as it flows over the leading edge , is definitely accelerated by dynamic pressure. I'm talking about the flow that is closest to the upper convex surface i.e. the flow that hugs the upper shape. The flow above this region does not change in velocity. It's all available to see in the video , I'm not making this up , just slow the footage down. Flow just under the foil is slowed down so an increase in static pressure arises , hence thicker smoke flow in that region. Further below that velocity does not change. To recap , flow immediately above the foil is accelerated and flow immediately below foil is deaccelerated. Air flows that fall out of this domain are unaffected. From observation there is acceleration of fluid immediately above and fluid deacceleration immediately below , so there is a speed differential in fact. However this does not explain lift. Atmospheric pressure pushes down on the flow over the upper surface so it follows the shape of the foil. This flow , due to inertia(Newton's 1st law) , resists atmospheric pressure and so must be deducted from the total pressure above the foil. To further clarify , the resistance is due to the flow not wanting to change direction as it follows the rounded shape , just like centrifugal forces. This is how a pressure differential is achieved, which generates lift, not by Bernoulli but by Newton. Bernoulli accounts for the speed differential that occurs above and below the foil, Newton accounts for the pressure differential that occurs above and below the foil.

@@singh2702 Albeit for entirely different reasons, we agree that the Bernoulli Principle has nothing to do with the aerodynamic force (lift/drag). But can you cite a reference providing the mechanics behind the "Newton's Law" explanation? Using mass, momentum, density and velocity, can you show how a light C172 at 100 kts can generate the 10,000 Newtons to balance its 1,000 kg weight, or a B747 at 300 knots can generate the 5,000,000 Newtons of force to balance its 500,000 kg weight?

@alans172 Take the difference in pressure per square inch, which is very small BTW, and multiply it by how many square inches make up the surface area of the wings. Common sense. That's why low-speed aircraft have wings with large surface areas.

Thank you for sharing!

The EPSRC CDT in Future Propulsion and Power builds on the success of the EPSRC CDT in Gas Turbine Aerodynamics. It will provide training in the key skills that future engineers in the field of Propulsion and Power will need to become leaders in research and design. www.turbocdt.org/course-information/