三维波束成形麦克风阵列在风洞测试中的应用

3D Beamforming Microphone Array Used in Wind Tunnel Acoustic Localization

得益于非常安静的背景噪声(风速140 km/h,声压级小于58 dBA)和优秀的低频压力脉动(Cprms<0.005),中国汽车工程研究院(CAERI)风洞中心的气动声学风洞为汽车空气动力学开发提供良好的声学测试平台。中国汽研风洞中心安装一套由3块麦克风阵列(3×168通道)组成的三维麦克风阵列测试系统,对车外气动噪声源进行定位及分析。采用“声学照相机原理”,即噪声云图通过波束成形的高级算法投射到车身三维表面(3D)上进行定位显示。

Thanks to very low background noise(e.g.,the sound pressure level is less than 58 dBA at wind speed of 140 km/h)andexcellent low-frequency pressure pulsations(Cprms<0.005),the CAERI aero-acoustic wind tunnel provides a good acoustic test platform for automotive aerodynamics development.In the process of automotive original development,it is important to quickly and reliablye valuate the acoustic sources for the improvement of ride comfort.The CAERI wind tunnel has been equipped with a test system consisting of a three-dimensional microphone array to evaluate the aero-acoustic sources.By using the“acoustic camera”,the noise contour map was overlaid on the surface of the three-dimensional digital car model through an advanced algorithm of beamforming to locate noise sources.