Self-sustained oscillations in supersonic overexpanded impact jets

The influence of geometric and gas-dynamic parameters on the flow structure and parameters of self-sustained oscillations in supersonic overexpanded jets interacting with a normally located plane finite obstacle is studied experimentally and theoretically. It is found that the geometric Mach number and the half-angle of nozzle expansion exert a significant effect on the interaction process. A comparison of experimental and numerical data allows one to find a possible reason for the emergence of self-sustained oscillations in overexpanded impact jets.