蜗壳式混流泵空化特性分析

基于Rayleigh－Plesset空化模型和剪切应力输运湍流模型(SST),应用计算流体动力学(CFD)技术，对比转速ns=449的蜗壳式混流泵设计工况下的流场进行数值模拟．根据模拟结果获取了该泵的空化特性曲线，捕捉到混流泵内空化的发生和发展过程，对开始发生空化、临界空化和空化严重3种工况下叶轮内的空化现象进行分析．分析结果表明:该泵空化性能满足设计要求; 混流泵叶轮内的空化现象最初发生在叶轮流道内，随着净正吸头的降低，叶片背面靠近轮缘处开始出现空泡，该空化区域从轮缘向轮毂方向延伸．在空化严重时会造成叶轮流道的严重堵塞，导致混流泵扬程的下降.

Cavitation Performance Analysis of Mixed-flow Pumps Based on CFD

The cavitating flow in a mixed-flow pump with volute collector under the design working condition was simulated numerically based on the cavitation model Rayleigh－Plesset equations and the SST turbulence model ,and the computational fluid dynamics(CFD)was used. The NPSHA-Hcurve was extracted from the results，the cavitation inception and development were captured as well．The cavitation phenomenon in the impeller were comparatively analyzed under the begin，critical and severe cavitation conditions．The results show that this pump has met the requirement on its cavitation performance．The cavitation phenomenon was first occurred in the impeller passage inside .Along with the NPSHA reduce, blade back near the leading edge began to appear cavitation. The cavitation area from the leading edge to the hub direction extensions, and the serious blockage due to cavity in the flow passages results in a reduction in pump head under the sever cavitation condition．The study fruits can instruct the cavitation performance analyses of other mixed-flow pump with volute．