Question Sir,why the symmentric aerofoil used in supersonic aircrafts?any reason behind this?besides what about unsymmentric aerofoil?
Answer Subsonic airfoils are usually cambered to help turn the flow and obtain lift. The primary goal of the supersonic airfoil is to minimize wave drag and control shocks. Thus, supersonic airfoils are very thin with sharp leading and trailing edges. A diamond shape, for example, allows control of the shocks because shocks attach to corners. And the bow shock is avoided. Camber is not needed to turn the flow because even a small angle of attack will provide adequate lift at supersonic speeds. In fact, the shocks are also used to obtain lift and much care goes into the design shock geometry. For subsonic landing, leading edge devices or flaps are needed to obtain the necessary lift at low speed. An unsymmetric airfoil might be used for supersonic flight if the resulting wing/body shock geometry and wave drag were optimized.
Aeronautics, Aerodynamics, Fluid Mechanics, Aeroacoustics, Noise Control, Muffler Design, Wind Tunnel Research.... I know nothing about India - do not ask about schools, jobs, application requirements, career choices, etc. for India. Please, no text message verbiage; I prefer full words in full sentences. Thanks.
38 years as research engineer at NASA
Publications AIAA, NASA
Education/Credentials B.S. and M.S. Aeronautical Engineering - U. of Washington,
Graduate work Standford U.
Awards and Honors AIAA Associate Fellow (American Institute of Aeronautics and Astronautics)