中文摘要：

为解决离心泵停机过程数值模拟时施加边界条件的困难，建立了一个包含离心泵在内的封闭循环管路系统从而实现自耦合求解。结果显示；停机过程中流量下降历程滞后于转速下降历程，而扬程下降则较为迅速；液流角或叶片冲角的持续改变是内部流动出现持续变化的直接原因；动静干涉效应使得稳定运行工况下的流量呈现微小波动特征，而非恒定值；停机过程表现出明显的瞬态效应，准稳态假设无法适用于停机过程精确瞬态行为预测。借助于CFD技术初步揭示了离心泵停机过程中的瞬态特性，为其它叶轮机械的瞬态行为研究提供了很好的借鉴与参考。

英文摘要：

To overcome the difficulty in implement of boundary conditions in the numerical simulation of transient flow in a centrifugal pump during stopping period, a closed-loop pipe system including the pump was built to accomplish a self-coupling computation. The results show that the decreasing course of flow rate lags behind that of rotational speed, and the head decreases more quickly. The continuous variations of flow angle or angle of attack are the root reason for the evolution of flow field in the pump during stopping period. The rotor-stator interaction makes flow rate present a slight fluctuation feature, in other words, the flow rate isn＇t invariable in a steady operating condition. During stopping period a considerably transient effect has been demonstrated, such an effect cannot be predicted precisely by means of a flow model based on the quasi-steady assumption so far. In conclusion, the transient characteristic of the centrifugal pump has prelimi- narily been revealed by using the CFD technique during stopping period, and the present method has provided a valuable reference for investigating into the transient behavior of other turbomachinery.