EXPERIMENTAL AND NUMERICAL VISUALIZATIONS ON FIXED AND PITCHING AIRFOILS IN DEEP DYNAMIC STALL

摘要

A number of starting flows past fixed and pitching airfoils ate investigated by means of experimental and numerical visualizations. The study is limited to some incompressible cases in which the flow is generated around a NACA 0012 airfoil in a quasi two-dimensional regime. The main interest of the research is the combined effect of pitching frequency and pitching $xis on the vortex formation. It is shown that the high-frequency pitching airfoils can yield either periodic vortex wakes synchronized with the pitching motion or gradually developing standing vortices produced on the upper surface.