循环水槽推进叶轮近场辐射噪声数值模拟

Numerical Simulation of Near Field Radiated Noise of Circulating Sink Impeller

为研究大型循环水槽中推进叶轮的辐射噪声特性,建立叶轮和管道的模型并对其进行数值模拟。采用计算流体力学(CFD)方法和滑移网格方法实现推进叶轮旋转,研究定常流场中推进叶轮的水动力和声辐射。在叶轮周围和桨轴后部布置一圈环形测点和一列轴向测点,监测叶轮径向和轴向各测点处的压力脉动,通过傅里叶变换得到各测点的噪声频谱。结果表明,推进叶轮轮缘处的噪声大致相同,在低频处声压级呈周期性变化,在高频处声压值不断减小,推进叶轮桨轴后的轴向测点声压随着距离的增加而迅速变小。

In order to study the noise radiation characteristics of propulsive impeller in large circulating water tank, the models of impellers and pipes are established and numerically simulated. Based on CFD, sliding gridding technique is used to realize the rotation of propulsive impeller. The hydrodynamics and the sound radiation of propulsive impeller in the steady flow field are studied. Circumferential and axial monitoring probes are arranged around the impeller and behind the propeller shaft to monitor the pressure fluctuation at the radial and axial measuring points of the impeller, and the noise spectrum of each measuring point is obtained by FFT.. The results show that the noise at the impeller rim is very similar. The sound pressure level changes periodically at low frequencies and decreases continuously at high frequencies. The sound pressure level decreases rapidly against the distance away from the impeller.