圆柱绕流近壁面处气动噪声源识别研究

对物体高速行驶下的气动噪声现象的认识和描述一直以来都是气动声学领域探索的基本问题和难点问题,尤其对物体近壁面处声源的产生及其声辐射缺乏有效的描述手段。该研究以圆柱绕流为研究对象,结合数值仿真手段,基于涡声方程的声源项描述圆柱绕流近壁面处的声源特性,建立声源识别方法。研究表明,该方法描述的声源存在不该有声源的位置出现声源的现象。研究进一步基于质点振速的矢量波动方程,将不能辐射噪声的源分离,较为准确地识别出了圆柱绕流气动噪声源的大小和位置。该研究在探索识别圆柱绕流气动噪声源方法的同时,也为准确识别气动噪声源特征提供了有效的方法。

Study of identification method for aerodynamic noise sources in flow around cylinder

Understanding and describing aerodynamic noise phenomena at high speed of an object has always been a basic and difficult problem to explore, especially, there is a lack of effective means to describe the generation of sound sources and sound radiation on the surface of an object and its vicinity. In this study, the flow around a cylinder is taken as the research object, and combined with the numerical simulation method, the source term of the vortex sound equation is used to describe the sound source characteristics, and a method of source identification is established. The research shows that the sound source described by this method has the phenomenon that sound sources appear in the position where the sound sources are not supposed to have. Based on the vector wave equation of the velocity of acoustic particle, the intensity levels and locations of aerodynamic noise sources in the flow around a cylinder can be identified more accurately. This study not only explores the method of identifying the aerodynamic noise sources in the flow around a cylinder, but also provides an effective method for accurately identifying the characteristics of aerodynamic noise sources.