中文摘要：

在小流量工况下运行时离心泵叶轮进口会产生进口回流现象.采用标准k-ε湍流模型,应用ANSYS CFX软件对不同工况下低比转速离心泵进口处的三维湍流场进行了数值模拟,分析了流场内的速度分布.为减小进口回流的危害,提出了在离心泵进口加注高压水的回流控制方案.对注入不同压力的高压水后,数值分析了进口流场的速度分布和回流漩涡的形态变化,并对比分析了回流控制效果以及离心泵扬程和效率.结果表明：在进口处注入高压水能有效改善回流发生时的流场速度分布,减弱回流强度,降低回流发生的关键流量点;但高压水的注入在设计流量和大流量范围内还会降低泵的扬程和效率;综合考虑各种因素后选择在该叶轮进口处注入0.10 MPa的高压水作为本模型泵的回流控制方案.

英文摘要：

During part-load operation,recirculation was inevitably developed at pump impeller inlet.Based on standard k-ε turbulent model,the 3-D steady turbulent flow in a centrifugal pump was simulated under different conditions to analyze the velocity distribution of the recirculation flow field and the vortex morphology.To solve recirculation,a control strategy of injecting high pressure water into impeller inlet was proposed.The control effects,the recirculation vortex morphology and the pump head and efficiency with different injection pressure were analyzed and compared through numerical simulation.The result indicates that high pressure water injection can effectively control inlet recirculation and improve the velocity distribution in inlet flow field with decreased recirculation vortex strength and recirculation onset critical flow rate,but also with decreased pump head and efficiency.Based on the experiment results,the optimum injection pressure in the proposed control stratgy is 0.10 MPa.