I have been looking for solutions and come up with two popular explanations:
- Conservation of mass / Continuity
For a positive-cambered wing, the streamlines would be compressed/converged at the leading edge's upper part, forcing the airflow to accelerate in order to maintain the same mass flow rate at the entry and exit point.
- Air circulation
Air circulates around an airfoil in clockwise direction and hence accelerating the flow on the upper part.
Would like to ask:
- Is it appropriate to use conservation of mass / continuity to explain.
- What exactly causes circulation on airfoil?
Follow up on question 2, some explanations saying because of the sharp trailing edge, starting vortex is formed which forces the formation of bound vortex. If it is the case, how sharp an edge would lead to a starting vortex, and why it flows from the lower wing to upper wing?
Thanks for helping!