Science Buddies: "Ask an Expert"

Hi, I have a question about air speed velocity and wing shape - related to the air that flows over the top of an airfoil. My question has to do with additional airfoils, and whether if airfoils were lined up one in front of another and reversed so that the curvature related to air speed over the top of the first air foil (that is increasing speed) would be increased even further by an airfoil that's position is reversed vertically (upside down)? See attached word doc with image - hopefully it clarifies the question. Thank you!

rudykin,

Welcome to Science Buddies, and thank you for the question. I don't have access to a computer that i can draw an example, so I'll try to explain as best as I can. The concept here is somewhat misleading. It is in reference to Bernoulli's principal, which holds for a single flow field only. Which means that if two air particles in the same air stream are split by an air foil, the one flowing over the "top" must move faster than the one along the "bottom" such that the two particles end up at the trailing edge at the same time. The stream above doesn't stay accelerated in the way you have drawn. What you have is the way a jet engine compressor works. Each successive stage is reversed and the flow is compressed into a smaller and smaller space. I'll try to post more about this at a later time.

Oh, okay. I see. Yes, that's helpful. Thanks for your response!