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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。
The traditional aerodynamic acoustics point of view is that accurate acoustic measurements require that the background noise of the wind tunnel and the reflection of the tunnel be low enough that the microphone measurements have a sufficiently high signal-to-noise ratio that is unattainable in most wind tunnels. In recent years, the microphone phase array technology based on sonar and radar technology can greatly improve the signal to noise ratio of acoustic measurement by increasing the number of array microphones, and has the capability of noise source research and localization and is successfully applied to non-acoustic Study on Noise Sources Measurement and Noise Physics Mechanism of Fixed Wall Wind Tunnel. Based on phase array beamforming algorithm in frequency domain, the author developed a conventional closed wind tunnel phase array array system and related technologies. At the FD-09 wind tunnel, phase array calibration test and noise test of a civil aircraft were attempted. The results show that the phase array technology can accurately capture the true calibration sound source and technically verify that the phase array system is effective in measuring aerodynamic noise in a conventional closed wind tunnel.