Experimental investigation into noise induced by low speed cavity flow

Although the investigation of cavity flow mechanism for aircraft has been for a long time, the investigation level could not satisfy the demand of aircraft structure design in detail. In order to investigate the low speed flow mechanism of some 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 skill which will provide typical statistical value and power spectrum density function of fluctuation pressure. The characteristic frequencies are existed for fluctuation pressure power spectrum density. The characteristic frequencies are distilled and then the sound sources for different characteristic frequencies are identified and evaluated with phase array technology one by one. The strength of sound source varied with incoming flow agrees well with the variety law of fluctuation pressure swing. The mixture of fluctuation pressure test method and phase array technology will have to provide an effective way to investigate the cavity flow mechanism and control the noise induced by cavity flow.