基于大涡模拟的导叶式混流泵叶轮内压力脉动特性分析

为研究导叶式混流泵叶轮内部非定常压力脉动特性，在其叶轮进口截面及出口截面附近分别设置8个压力脉动监测点，采用大涡模拟方法(LES)对导叶式混流泵内全三维流道(进水管、叶轮、导叶及出水管)进行模拟，并对8个监测点进行压力脉动时域图和频域图的分析。结果表明:由于旋转叶轮旋转失速、脱流效应及静止导叶的干涉作用，叶轮出口处压力脉动系数幅值均大于进口处脉动系数幅值，且其最大压力脉动发生在叶轮出口处，脉动波衰减较慢；叶轮进、出口截面上监测点的压力脉动频率以叶轮叶频为主频次，且压力脉动主要频率为叶频的倍数。

Analysis of Pressure Fluctuations in Impeller of Guide Vane Mixed- flow Pump Based on Large Eddy Simulation

In order to investigate the phenomenon of pressure fluctuations caused by unsteady flow in impeller of guide vane mixed-flow pump, 8 pressure fluctuation test points were set on impeller inlet-plane and impeller outlet-plane respectively. LES was adopted to calculate the whole flow field which includes inlet pipe, impeller, guide vane and outlet pipe, and analyze the pressure fluctuation time domain graph and spectrum graph of 8 pressure fluctuation test points. The results shows thatdue to the stall andseparate flow of rotating impeller and interaction with static guide vane, the pressure fluctuation coefficient amplitude at outlet of impeller are greater than that at inlet of impeller, and the maximum amplitude pressure fluctuation occurs at outlet of impeller, and the impulse wave decays slowly. The main frequency of pressure fluctuations at impeller inlet-plane and outlet-plane is blade frequency and blade frequency is a multiple of impeller frequency.