中文摘要：

为提高多级离心泵的水力效率，借助于FLUENT软件，对多级泵叶轮和径向导叶不同组合、不同工况下的内外水力性能进行了研究．结果表明：叶片进口边扭曲度高的叶轮具有较高的效率；泵的效率和扬程随导叶和叶轮配合间隙的增大而降低；在变流量工作时，叶轮与导叶水力性能的最优匹配关系可能随流量的变化而发生改变；转速对叶轮和导叶匹配性能影响极小．叶轮和导叶内部流场分析表明：叶轮和导叶内部的涡流是降低泵水力效率的主要因素，提出适当增加叶片进口扭曲度、减小叶轮和导叶间隙，从而减弱内部旋涡是多级离心泵水力性能优化的方向之一．由试验结果可见：多级泵外特性的模拟结果与试验结果误差在10％以内．

英文摘要：

In order to improve efficiency of multistage centrifugal pump, hydraulic performance of different combination of impeller and radial diffuser under different operating conditions was studied by software FLUENT. It is found that the impeller has higher efficiency with higher blade distort degree at inlet end; the pump will decline on its head and efficiency with the decline of gap between impeller and diffuser; the best combination of impeller and diffuser may change with the change of flow and will not change with the change of speed. The internal flow field analysis shows that eddy current in impeller and radial diffuser is the main factor to reduce the hydraulic efficiency of pump. It is proposed that appropriate increase of blade distort degree at inlet end and reduction of clearance between impeller and diffuser, thereby to weaken the internal vortex, is one of the directions of hydraulic performance optimization of multi-stage centrifugal pump. Test of multi-stage pump performance shows that the error between simulation results and the experimental results is less than 10%.