离心泵内部流场的三维空化湍流的数值计算

Numerical evaluation of three-D cavitation turbulent flow in centrifugal pumps

采用Singhal等人发展的一种三维混合流体完整空化湍流模型,基于RNG的k-ε湍流模型和SIMPLEC算法,对离心泵内部的全流道三维空化流动进行定常和非定常数值模拟.根据空化流动模拟计算的结果,得到定常和非定常情况下空化余量和扬程的曲线,与实验结果进行对比,说明计算结果能够真实反映离心泵内部空化流动的性能.进而有效地预测叶轮内部流道空化发生的部位和空化流动的发展情况,分析空化余量的降低对离心泵空化性能的影响.研究结果表明,所采用的空化模型和数值计算方法能够用于离心泵在设计工况下的空化性能的计算.

Based on RNG k-ε turbulence model and SIMPLEC algorithm and by using the model of threedimensional full cavitation turbulent flow of mixed fluid developed by Singhal and others, the numerical simulation of steady and unsteady cavititation turbulent flows in the whole flow passage of a centrifugal pump was conducted. According to the simulation results of the cavitation flow, the NPSH-H curves were obtained for the steady and unsteady circumstances. Compared to the experimental results, the prediction results could be a true reflection of the internal cavitation flow performance of the pump, so that the region and degree of cavitation occurred in the flow passage of the impeller could be further predicted. The effect of the NPSH gradient on the cavitation performance of the centrifugal pump was analyzed. The results showed that the adopted cavitation model and the simulation calculation method could be used to predict the performance of the centrifugal pump in the design condition.