中文摘要：

采用三维定常雷诺时均Navier-Stokes方程和Spalart—Allmaras湍流模型，对复合叶轮离心泵内部三维流场进行整机定常数值模拟，得到了复合叶轮离心泵内部流场的速度分布和压力分布。分析在不同流量点下复合叶轮和蜗壳内部流场，揭示离心泵内部的重要流动特征，证实了过流部件间相互作用引起的离心泵内部流场的不对称性。数值模拟结果表明，复合叶轮离心泵的整机数值模拟分析能够较准确地预测出离心泵内部的流场结构及性能参数。

英文摘要：

The three-dimensional flow field of the low-specific-speed pump is analyzed numerically based on the Reynolds-Averaged Navier-Stokes equation and the Spalart-Allmaras turbulence model. The velocity and pressure distribution of complex-impeller pump is obtained. Under different flow-rate, the simulation results of impeller and volute reveal the important features of pump and verify the asymmetry of the internal flow due to the interaction of impeller and volute. The results also indicate that the structure of internal flow field and performance of pump with complex-impeller can be predicted by the simulation of flow field exactly.