一种基于声相似律的旋转流体机械噪声声源分离方法
A method for quantifying the source of flow noise in turbomachines based on acoustic similarity law
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摘要: 针对管道系统中的流体机械发声问题,提出了一种声源函数与声响应函数的频谱分离方法。该方法以声相似律为基础,分别采用最小均方值多重线性回归方法和高斯滤波获得声源函数和声响应函数。通过算例验证了该方法的有效性,辨识得到的声源函数和声响应函数的相对误差均远小于现有方法。利用该方法分析了自由空间和带管道两种安装条件下轴流风扇的辐射噪声,辨识得到了相应的声源函数、声响应函数和叶尖速度律指数,并对风扇的主要噪声成分进行了分析。Abstract: A noise source identification method is proposed to separate the noise source function and acoustic response function of the flow noise of turbomachines enclosed by ducts.Based on the acoustic similarity law,the noise source function and acoustic response function are obtained by least square multi linear regression method and Gauss filter respectively.The proposed method is proved to be effective by numerical simulations.The results show that the proposed method is much better than existing methods in terms of the relative errors of noise source function and acoustic response function.Two cases of a computer cooling fan working in free field and in duct are studied subsequently.The noise source function,acoustic response function and sound source tip speed exponent number are calculated by this method and the main components of the sound source are analyzed finally.