Wind tunnel test into noise induced by low-speed cavity flow

For the investigation of low-speed flow mechanism for a certain cavity, the fluctuation pressure test in wind tunnel and phase array technology are developed and applied in the paper. The method of fluctuation pressure test is a kind of scattered point test method which will provide typical statistical value and power spectrum density function of fluctuation pressure. The characteristic frequencies exist in fluctuation pressure power spectrum. The characteristic frequencies are distilled and the sound sources for characteristic frequencies are identified and evaluated with phase array technology one by one.The strength of sound source varying with incoming flow agrees well with the changing law of fluctuation pressure swing. The mixture of fluctuation pressure test method and phase array technology will provide an effective way to investigate the cavity flow mechanism and control the noise induced by cavity flow.