The aim of the present work is to show methods to locate aeroacoustic sources in a closed test section of wind tunnel by using 2-D microphone arrays. It is essential to reduce the flow-induced self-noise of microphones for accurate measurement of acoustic signal. In order to reduce the incoherent noise received by each microphone, the cross spectrum of the outputs from 2 pairs of spiral microphone arrays was calculated. Furthermore, surfaces of the microphones were covered with a thin film to suppress the flow-induced noise. The cross spectrum method was validated basically by speaker tests using white noise. Then these techniques were applied to wind tunnel tests on a pantograph model. The results show major acoustic sources from a panhead up to 60 m/s.

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