The flow around a circular cylinder for Re = 1000 is characterized by flow separation and Karman vortex street. The typical flow features can be captured to study the correlation between fluid fields and sound fields. In this paper, the three-dimensional circular cylinder is taken as the research object, and the probes of surface fluctuating pressure and far field sound pressure are arranged every 10°. The directional diagram and the coherence of fluctuating pressure and sound pressure are analyzed. The relationship between the flow mode and hydrodynamic noise is studied by using dynamic mode decomposition (DMD). The characteristics of the dipole and quadrupole sound source term of a long span cylinder are studied. The results show that at the angles between 30°–120° and 190°–350°, the fluctuating pressure contributes more to the generation of dipole sounds. The quadrupole sound source shows three-dimensional effects, which is more obvious in a cylinder with large spanwise length.

Re = 1000时圆柱体周围的流动具有流动分离和卡门涡街的特征。可以捕获典型的流动特征来研究流体场和声场之间的相关性。本文以三维圆柱体为研究对象，每隔10°布置表面脉动压力和远场声压探头。分析了脉动压力和声压的方向图和相干性。利用动态模态分解（DMD）研究了流动模式与水动力噪声之间的关系。研究了大跨度圆柱体偶极子和四极子声源项的特性。结果表明，在30°~120°和190°~350°之间，脉动压力对偶极子声的产生贡献更大。四极声源表现出三维效果，在翼展长度较大的圆柱体中更为明显。