ON THE INTERACTION BETWEEN THE SHOCK-WAVE ATTACHED TO A WEDGE AND FREESTREAM DISTURBANCES

We present a study of the interaction of small amplitude, unsteady, fr eestream disturbances with a shock wave induced by a wedge in superson ic flow. These disturbances may be acoustic waves, vorticity waves, or entropy waves (or indeed a combination of all three). Their interacti ons then generate behind the shock disturbances of all three classes, an aspect that is investigated in some detail. Also, the possibility o f enhanced mixing owing to additional vorticity produced by the shock- body coupling is investigated. It is shown that disturbances behind th e shock may either decay downstream, or alternatively experience susta ined oscillations. The precise regimes under which either behaviour is found are stated.