Alternative Theories of Lift
Alternative Theories of Lift ARE THERE ALTERNATIVE EXPLANATIONS OF LIFT? The explanation of lift favored by this website states that lift is created by an imbalance of pressure against a wing—lower pressure on the top surface and higher pressure on the bottom surface. This "pressure distribution" can be calculated accurately for both subsonic and supersonic flight. But there are other ways of explaining how lift is created. Title: Propeller Downwash image Downwash is especially noticeable beneath a helicopter's rotating blades. Credit: United Technologies Sikorsky Aircraft THE MOMENTUM EXPLANATION OF LIFT According to this explanation, the slight downward deflection of the air leaving the trailing edge of a wing is what produces lift. Since for every action there is an equal and opposite reaction, the downward push on the air must result in an upward push on the wing. But this “downwash” results from air pressure differences on the wing—it is an effect of lift, not the c...