小流量工况下低比转速离心泵内部流场的数值分析  

Numerical investigation of internal flow field in a low-specific speed centrifugal pump at low flow rate

作　　者：李凤琴[1] 李昳[1] 李晓俊[1] 夏密 

机构地区：[1]浙江理工大学浙江省流体传输技术重点实验室,浙江杭州310018

出　　处：《机电工程》2015年第11期1438-1442,共5页Journal of Mechanical & Electrical Engineering

基　　金：浙江省自然科学基金重点资助项目(LZ15E090002);流体及动力机械教育部重点实验室开放基金资助项目(SZJJ2014-034);浙江省151人才工程和浙江理工大学流体工程技术创新团队资助项目(11132932611309)

摘　　要：针对小流量工况下低比转速离心泵内部流动特性问题,通过运用计算流体力学软件FLUENT,并采用RNG k-ε湍流模型和SIMPLE算法,对离心泵内部流场进行了数值模拟。采用3种不同网格数对离心泵模型进行了网格无关性分析以验证提高数值计算的准确性。沿进水管道至其进口端设置了监测点,分析了周向速度和轴向速度,得出了不同工况下发生回流的位置,分析比较了4种流量工况下离心泵内部的流场分布。结果表明:0.7Qd工况下,进水管道和叶轮流道中的流线均比较平滑,离心泵内部流动比较稳定。0.6Qd工况下,叶轮进口和叶轮流道开始产生了漩涡。随着流量的进一步降低,叶轮进口回流强度增大,叶轮流道中的漩涡逐渐向其相邻流道中扩展,离心泵内部的流态十分紊乱。Aiming at investigating flow characteristics in a low-specific speed centrifugal pump at low flow rates,calculations were performed with a commercial software package,FLUENT. Turbulence was simulated with the SIMPLE algorithm based on the RNG k-ε model. The grid independence was checked by applying three kinds of mesh to improve the accuracy of numerical simulation. Monitoring points were created from the impeller inlet to the suction inlet to get backflow location at different flow rates. Based on the comparative analysis of the velocity and pressure distributions,the results indicate that the streamlines of suction and impeller passages are quite smooth and the flow is stable in centrifugal pump at 0. 7Qd. Vortical structures are first observed in the inlet of impeller and impeller passages at 0. 6Qd. With further decreasing flow rate,the strength of backflow in impeller inlet is intensified and vortexes in impeller passages are extended to the adjacent passage.The whole flow patterns become disordered.

关 键 词：离心泵 低比转速 数值模拟 回流 漩涡 

分 类 号：TH311[机械工程—机械制造及自动化] TH122