基于结构化网格的离心泵全流场数值模拟

摘要

采用计算流体力学(CFD)方法对全流场模型下离心泵的性能进行了分析.阐述了离心泵计算区域的拓扑块生成和结构化网格划分方法；分析了全流场模型和非全流场模型的数值模拟结果,并比较两者产生差异的原因.证实了腔体的存在对模拟结果的影响,得到的全流场数值模拟性能预测精度优于非全流场数值模拟,其流态分布也存在显著的差别,并获得了口环泄漏量与离心泵流量和扬程的关系.将离心泵全流场模型的模拟结果与试验值进行了对比:设计工况点(Qd),离心泵的扬程相对误差为0.79％,效率相对误差为0.9％,模拟结果和试验结果比较接近；在0.2Qd时,扬程相对误差为6.24％,效率相对误差为9.61％,极小流量点的数值模拟精度有待提高.%The performance of centrifugal pump with whole flow field was analyzed by using CFD technique.The blocking strategies and mesh generation on domains of the pump were presented.Numerical simulation of whole flow field model and simple model in CFX for the pump was then carried out and the reason of the difference between two models was compared.It was verified that the cavity indeed had effects on simulation results.The whole flow field model showed a higher accuracy than the simple model,and the flow pattern of two models were also different.The relationship between the subflowrates through front cavity and the overall performance of the pump was evaluated.The simulation results of whole flow field model and the measured results were compared.The relative errors of the head and efficiency were 0.79％ and 0.9％ at the normal flow rate Qd,while they were 6.24％ and 9.61％ at 0.2Qd.The accuracy of numerical simulation should be improved at minimal flow point.