Study of Interaction between Supersonic Flow and Rods or Jets Surrounded by Porous Cavity

Abstract

In this experiment, the effects of the combination of jets or rods and a porous cavity on the supersonic flow field are studied by means of visualization of schlieren method and the measurements of wall static pressures and the flow direction in the cavity with the thermal tuft probe. Three cases of jets or rods arrangements are tested in the experiments. As a result, a bow shock wave which is generated by the jets or rods is observed by mean of schlieren method. And it is confirmed that the expansion region appears downstream of the rods but is not in case of the jets pattern. Moreover the pressure ratios of starting shock wave passing through porous cavity for jets pattern differ from that of rods pattern. In the cavity, the flow direction at the measurement position in the cavity is always opposite to the main flow, as long as the starting shock wave is located upstream of the porous cavity for all cases. Difference in the backward flow ratio between the jets and rods patterns is observe after the starting shock wave passes through the porous cavity.

Experimental Investigation of Effect of Rods Inserted into Supersonic Main Flow on Porous Cavity Flow

“…Figure 5 shows the starting shock wave positions on the lower wall for 000, 010, 030 and 111. In this figure, previous results reported by authors 9,10) are shown as a reference. Dashed lines indicate a start and an end of the cavity.…”

“…The flow in the cavity is spouted again, achieving small fine injections through many small porous holes. Using the device, we already evaluated the effect of the combination of porous cavity and the rods or jets on the flow 8,9) . Accordingly the flow direction is affected not only by the rods and jets also by the relative position of the starting shock wave to the cavity.…”

Numerical Study of Injected Jets into Supersonic Main Flow from a Porous Cavity

“…This flow field has experimentally investigated with Schlieren method, pressure measurements, and a thermal tuft probe which can detect flow directions. [9][10][11][12] As a result, it is found that the cavity flow is affected by the jets arrangements, which concerns the three dimensional structure of the bow shock wave. In the experiments, it is difficult to clarify the detailed three-dimensional flow around the cavity and the circulation between the main flow and the cavity flow at the same time.…”