Experimental study of unsteady supersonic flow interacting with porous cavity and jets or rods

In this study, an experiment was performed to clarify the flow field, in which the jets were normally injected into a main supersonic flow surrounded by a porous cavity, and this report figures out interaction between starting shock wave and porous cavity. In the experiment, a porous cavity is attached to a main duct and jets and rods are inserted to the main duct on the porous cavity. To reveal this flow field, the thermal tuft probe was adopted to experimentally investigate the flow in the cavity. In the experiments, the effect of the porous cavity with jets or rods on the flow field is studied by means of visualization of schlieren method with a high speed camera and measurement of cavity flow with thermal tuft probe. As a results, frequency analysis of output of the thermal tuft probe revealed that some clear dominant frequencies were confirmed when the starting shock wave existed around the porous cavity in all cases of jets and rods arrangements. Moreover, visualization of schlieren method with a high speed camera clarified that a starting shock wave had the same dominant frequencies as that of the flow fluctuation in the cavity only around the cavity.