Abstract
When the underexpanded supersonic jet impinges on the obstacle, the self-induced flow oscillation occurs at the specific condition and this oscillation is related with the noise problems of aeronautical and other industrial engineering. The investigation for the self-induced flow oscillation was carried out during and the underexpanded supersonic jet impinged with the cylindrical body. The wave structure formed in the flowfield and the pressure change with time at the cylindrical body were obtained by the experiment. From the result of this investigation, it is cleared that oscillated shock wave differs by the pressure ratio of flowfield and the peak frequency of an oscillation depend on the pressure ratio of flowfield.
