Numerical study on pitching oscillation flow control over asymmetric vortex structure of slender revolution by using DES

To study the separation vortex on the leeside of slender body at the time of pitching oscillation, the RANS/LES hybrid methods based on S-A model was presented to simulate separated flow at two typical starting angles of attack. The result shows that the pitching oscillation greatly affects the flow field around slender body; the pitching oscillation obviously control the asymmetry separation vortex. While multi asymmetric vortexes at high angle of attack don't break down and multi asymmetric vortexes break down in turn at extremely high angle of attack, the pitching oscillation has strong control ability, and the asymmetrical flow is restrained and tends to symmetrical flow.