Jetstream Rider

See here:
Lift from Flow Turning

The last bit:
Summary

Lift and drag are mechanical forces generated on the surface of an object as it interacts with a fluid. The net fluid force is generated by the pressure acting over the entire surface of a closed body. The pressure varies around a body in a moving fluid because it is related to the fluid momentum (mass times velocity). The velocity varies around the body because of the flow deflection described above.

I'm happy that mathematical descriptions for lift are far from exact, are necessarily approximations and sometimes are quite wacky (yet still yield good results). I'm also happy that we don't have an analysis toolkit that is good enough to describe flow and lift adequately (especially not turbulence), regardless of computer size or complexity of model. What I was after by starting this thread was to improve my conceptual understanding.

Anderson says "...the aerodynamic forces and moment on the body are due to only two basic sources: 1. Pressure distribution over the body surface 2. Shear stress distribution over the body surface".

My current understanding therefore is that in a flow, energy, mass, and momentum are conserved. In doing so and by passing flow around a closed surface the pressures and therefore forces within that fluid change. This causes lift, by a number of mechanisms including viscosity and we can roughly
describe it. The force on the closed body is caused by pressure changes and shear stress distribution, these pressure changes are caused by "turning" the flow and by the fact it has momentum. By turning it carefully and with experience we can approximate what nature will give us.

In short, lift is complex and hard to understand and we've not got that near describing it exactly by using mathematics. We do know however that it is caused by pressure changes within a fluid, caused by flow turning and the fact it has momentum.

Any disagreements?