Theory on lift

[Lyman]

Hi Owain

I understand the problem related to compression (pressure) and Newton. That is why I always use mass when discussing the theory.

Any (local) 'modification' of a dynamic system involving a gas involves transient exchanges of energy, and is far more complicated than pushing an object up an inclined plane.

There are seductive traps which require patience. Newton #3 works fine for thrust; there is no reason to eliminate the other two from GE discussion, imho.

Thanks for all your time here, I am learning.

HazelNuts39

I like the upwash imagery. In fact, I like your approach in general, involving as it does visualisation. So far, I am looking at the enhanced products of GE as a result of Newton's Second Law. The 'shape' of the area under the a/c describes a volume of increased pressure, due to the stream tube resisting the descent of the planform onto it. I have used the image 'piston' in the past.

The stream tube is being pinched as it migrates aft toward the convergence of the underwing and ground streamlines?