单叶片离心泵水动力噪声特性数值分析

基于LIGHTHILL声类比理论，根据FW-H方程，采用计算流体力学与计算声学相结合的方式对单叶片离心泵的内部噪声进行求解，探究其不同流量工况下内部流场的声源特性.采用混合数值模拟的方法，运用SST k-ω湍流模型对离心泵进行非定常模拟，并导出声源信息，对其进行声学计算求解，同时分析不同流量下的单叶片离心泵的内场噪声，比较其影响.研究结果表明：单叶片离心泵压力脉动的能量主要集中在叶频及其低频段谐频处，内部噪声的能量主要集中在低频段，并且在叶频及其谐频处噪声的能量较高；随着流量的增加，蜗壳与叶轮流道内流态逐渐改善，二次流、流动分离现象减少，导致低频段的谐频噪声呈现明显的下降趋势.根据不同流量下的声功率级频谱分析可以发现，压力脉动的分布特性对于单叶片离心泵的内部水动力噪声有直接的影响.

Numerical analysis of hydrodynamic noise characteristics of single-blade centrifugal pump

Based on LIGHTHILL acoustic analogy theory and FW-H equation, computational fluid dynamics and computational acoustics were used to solve the internal noise of a single-blade centrifugal pump, and the sound source characteristics of the internal flow field under different flow conditions were explored. A hybrid numerical simulation method and the SST k-ω turbulence model were adopted to perform unsteady simulation of the centrifugal pump. The sound source information was exported, and acoustic calculations was performed. The internal field noise of single-blade centrifugal pumps at different flow rates was analyzed. The results show that the energy of the pressure pulsation of the single-blade centrifugal pump is mainly concentrated in the blade frequency and its harmonic frequency in the lowfrequency range. The energy of the internal noise is mainly concentrated in the low frequency band, and the energy of the noise component is higher at the blade frequency and its harmonic frequency. With the increase of the flow rate, the flow pattern of the flow channel in the volute and the impeller is gradually improved, and the secondary flow and flow separation phenomenon was reduced. It results in an obvious downward trend in low frequency harmonic noise. According to the frequency spectrum analysis of the sound power level under different flow rates, it can be found that the distribution characteristics of the pressure pulsation have a direct effect on the internal hydrodynamic noise of the single-blade centrifugal pump.