关键词: 声学, 轴流风机, 旋转叶片, 气动噪声, FW-H方程, Fluent 软件

Abstract:

Abstract: In views of the aerodynamic noises generated by axial fan, a three-dimensional model of this kind of fan is built. Lighthill acoustic analogy theory, FW-H acoustic wave equation and FLUENT numerical simulation are used to analyze the characteristics of aerodynamic noises arisen from the axial fan’s rotating blades. The simulation result shows that the static pressure of rotating blades is mainly distributed on the front side of blades. However, the fluctuating pressure is distributed on both sides and mainly in the margin of blades, which is caused by the severe air turbulence from the vortexes in the outer edge of blades. The acoustic power of blades is also distributed in the margin of blades, but its characteristic of distribution is different from that of fluctuating pressure, indicating that the aerodynamic noises of rotating blades are not all produced by fluctuating pressure. In addition, the faster the blades rotate or the larger the blade’s diameter is, the more intense the aerodynamic noise is.