Owain, if your fear is that some innocents may be harmed by rubbish, could you address the scientists' 'rubbish' specifically?
I didn't say that the Anderson/Eberhardt paper was rubbish. I think it simplifies things a little too much and it can be misleading. For example this business that Bernouilli's equation cannot be applied to the flow around a wing (or indeed any surface where there is an energy transfer from body to air). As they say, Bernouilli's equation applies in a constant energy situation, and strictly applies along a streamline. But the energy variations are confined to areas inside the boundary layer where the flow is chaotic and there are no streamlines. However, there is no transverse static pressure gradient across the boundary layer, so the pressure at any point on the actual wing surface is the same as that immediately above that point on the streamline at the edge of the boundary layer where Bernouilli can be applied.
But if I criticise some points I should also say where I agree. For example, they are correct when they say:
The streamlines are bent by a lowering of the pressure. This is why the air is bent by the top of the wing and why the pressure above the wing is lowered. This lowered pressure decrease with distance above the wing but is the basis of the lift on a wing
Put another way [Holger Babinski "How do wings work?" ww.iop.org/journals/physed
In other words, if a streamline is curved, there must be a pressure gradient across the streamline, with the pressure increasing in the direction away from the centre of curvature.
This relationship (derived mathematically in the appendix) between pressure fields and flow
curvature is very useful for the understanding of fluid dynamics (although it doesn’t have a name). Together with Bernoulli’s equation, it describes the relationship between the pressure field and the flow velocity field.
This may be at right angles to the direction of acceleration most think of in connection with wing flow, but it is correct.
Again, my diagram was an attempt to explain circulation theory. Their paper says:
Yet another common description of lift is that of circulation theory. Here the air is seen to rotate around the wing. This is sometimes used to explain the acceleration of the air over the top to the wing. There is a great deal of jargon, such as "starting vortex" and "bound vortices", associated with this description. Circulation theory is a mathematical abstraction useful and accurate for aerodynamic calculations. ....... Circulation is a model
developed for large aircraft .......
and:
Although circulation theory can be used for accurate calculations of lift, it does not give a simple, intuitive description of the lift on the wing
I was trying to give an intuitive description of this way of looking at the problem - a theory they accept as accurate btw.
My question is a general one. From whence comes the force supporting that monstrous mass in the air? Beneath the wing, as pressure, or above the wing, as "pull"?
You know the answer to that! Bit of each but mostly from above and most of that from suctions in the first 30% (ish) of the chord.