Active control of wave instabilities in three-dimensional compressible flows (Q1291852)

Based on suction and blowing at the wall, and linked to measurements of surface pressure or wall shear, an active control strategy is discussed for a variety of model equations. The cases of high and finite Reynolds numbers are discussed using the asymptotic triple-deck approach as well as numerical solution of the parabolized stability equations. Using this control concept, it is shown that Tollmien-Schlichting waves in incompressible as well as in compressible flows can be fully stabilized. The same is true for attachment-line instabilities. However, for the basically inviscid crossflow instabilities on a swept wing or for Görtler instabilities, the simple control law based on modifying the near-wall structure was not very successful.