Abstract
The relation between pressure fluctuation inside a rectangular cavity and flow structure around the cavity was investigated experimentally. The cavity was installed in supersonic internal flow at Mach numbers 1.83 and 2.13. The length of the cavities was varied from 10 to 40 mm, whereas the depth was kept at 20 mm. In order to observe the flow structure around the cavity, three kind of methods; schlieren method, tracer method and oil flow method were applied. The pressure fluctuation inside the cavity was measured by using pressure transducers. It was found that the amplitude of the pressure fluctuation was large when the flow structure inside the cavity was unstable, and the amplitude was small when the flow structure was stable. It means that the amplitude of the pressure fluctuations is much influenced by the flow structure inside the cavity.
