以输气管道中气体流经阀门时产生的气动噪声为研究对象,采用两种方法获取气动噪声声源:一种是只采用CFD软件进行计算和分析(FW-H法)；另一种是采用CFD软件联合声学软件进行仿真计算(BEM法).建立气动噪声模型,得到气动噪声的产生、传播和衰减规律.结果表明:流场中的压力脉动和速度脉动是输气管道中气动噪声产生的根本原因；输气管道中的阀门噪声源为偶极子声源和四极子声源,在低马赫数下,偶极子声源占主要地位；偶极子声源分布在阀门表面上,四极子声源分布于整个流场中；两种方法均能较好地求解输气管道气动噪声的产生、传播和衰减问题,FW-H法操作简单,计算精度较低,但只能计算声场“远场”,而BEM法计算效率高、精度高,能够对声场中任一点的声学量进行求解.%Aerodynamic noise generated by the gas flowing through the valve in the gas pipeline was taken as the research object, and two methods were used. One method is to apply CFD software only(FW-H) and the other is the numerical simulation using CFD software combined acoustic software(BEM). The aero-acoustics models were built and the generation, transmission and attenuation laws of aero-acoustics noise were given. The results show that pressure fluctuations and velocity fluctuations in the flow field cause aerodynamic noise in the gas pipeline. The quadrupoles and the dipoles are the main components of the valve noise. When the Mach number is low, the dipoles distributed on the surface of the valve are dominant and the quadrupoles distribute in the whole flow field. Both methods can solve the generation, propagation and attenuation of aerodynamic noise in gas pipelines. FW-H method is simple to be operated with low accuracy, and this method can only compute the far field of sound field. BEM method is efficient with high accuracy and it can compute the sound field of each point.
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