喷水推进双级轴流泵流体动力性能CFD分析

Hydrodynamic analysis of a waterjet two-stage axial-flow pump based on CFD

采用高质量结构化网格对某喷水推进双级轴流泵整个数值模拟系统的各部件进行区域离散,利用CFD方法预报该泵扬程、功率和效率等外特性,分析其内部流动情况。计算结果与实验数据的较好吻合证明了CFD方法可以作为通过试验求取喷水推进双级轴流泵特性曲线的辅助方法。研究中对有、无轴情况下双级轴流泵外特性的预报和比较结果表明,轴对该泵动力性能预报结果影响不大;通过计算叶片压力分布,验证了该双级泵叶轮叶片设计中采用的线型;通过观察一、二级导叶出口的流动状态,分析了该泵设计中存在的缺陷,并为导叶改进设计提出建议。

The hydrodynamic performance of a waterjet two-stage axial-flow pump and its internal flow field are simulated and analyzed by computational fluid dynamics （CFD） method. Each part of the numerical model was meshed by high quality hexahedral mesh. The macro-parameters such as total head, power and efficiency of different mass flow rate at the same rotating speed were obtained. The results agreed well with test data. It was proved that the CFD method could be an assistant method of experiment to predict the performance of the waterjet two-stage axial-flow pump. In this study, both performance prediction of the pump with and without the shaft were carried out, but there was little difference in the prediction results. The impeller line-type adopted was validated by calculating and analyzing its pressure distribution. After observing the flow patterns at the first and the second stage stator＇s outlets, a fault in design was obtained, and some proposals for improving stator were offered in the end.