Experiment research of the noise reduction technology based on flap edge side fence

The noise reduction technology based on flap side edge fence was verified in the aeroacoustic wind tunnel. The noise reduction level of three types of flap fences was tested by microphones phased array and far-field microphones, the data was analyzed by means of beamforming, sound pressure level integration and spectrum analysis. The test results show that the noise generated from the flap side edge dominated in the frequency range from 5kHz to 16kHz, and the flap fence can reduce the flap side edge noise obviously in this frequency range. As the affection of fences to the noise of clean configuration is small, the flap fences have a great engineering application prospect. Comparing the effectiveness of noise reduction of three fences, the noise reduction level of fences is found to be related to the flap angle and the shape of the fences. For the current three types of fences, the larger fence get the better noise reduction performance.