常规闭口风洞相阵列气动声学试验

传统气动声学研究观点认为,精确的声学测量要求风洞背景噪声和洞壁反射足够低,传声器测量结果有足够高的信噪比,这是大多数风洞无法达到的要求.近些年,基于声纳和雷达技术发展起来的麦克风相阵列技术可以通过增加阵列的传声器数目从而大幅提高声学测量的信噪比,具有噪声源研究和定位能力,并被成功地应用于非声学固壁风洞噪声源测量和噪声物理机制研究.作者基于相阵列波束生成频域算法研制出常规闭口风洞相阵列系统及相关技术,在FD-09风洞尝试进行了相阵列校准试验和某民机噪声测量试验.结果表明:相阵列技术能够准确捕捉到真实的校准声源,并从技术上验证了相阵列系统在常规闭口风洞测量气动噪声是有效的.

Aeroacoustic phased array measurements in closed-section wind tunnel

As conventional viewpoint,aeroacoustic measurements require low background noise and minimal reflections for accurate results.So proper design of wind tunnel components and test apparatus are critical to successful aeroacoustic measurements.Over the past several years,microphone phased arrays have been developed based on sonar and radar technology.One of the biggest advantages is that the signal to noise ratio(SNR) is increased with the number of sensors in the array.This technology can be used to measure and identify the noise sources.It has been used in non-acoustic,hardwall wind tunnels,as a research tool to gain insight into noise and into the physical mechanisms causing the noise.Based on the frequency domain approach of beamforming algorithm,microphone phased array system has been developed by the author for aeroacoustic measurements in low speed closed-section wind tunnel.Array calibration and aeroacoustic measurements for a commercial aircraft were performed in FD-09 wind tunnel.The results indicated that array can identify the calibration resource accurately,and the availability of aeroacousitc measurement was validated by array calibration and application in low speed closed-section wind tunnel.