单叶片螺旋离心泵内部流场数值计算及油膜试验研究  

Numerical simulation and oil film observation on flow field in impeller of screw centrifugal pump with single-blade

作　　者：张华[1] 陈斌[1] 施卫东[2] 王炳祺[1] 王震 

机构地区：[1]合肥工业大学化工机械研究所,安徽合肥230009 [2]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013 [3]蓝深集团股份有限公司,江苏南京211500

出　　处：《排灌机械工程学报》2016年第5期381-385,共5页Journal of Drainage and Irrigation Machinery Engineering

基　　金：中央高校基本科研业务费专项资金资助项目;合肥工业大学"秋实计划"A类计划项目

摘　　要：针对比转数为240的单叶片螺旋离心式潜水排污泵内部流场,采用数值计算与试验相结合的手段进行研究.以多面体网格为划分形式,应用Realizable k-ε湍流模型,对其进行了全流场定常数值计算,并将计算结果与外特性试验结果及油膜试验结果进行对比.研究结果表明:数值预测的外特性及叶轮表面迹线结果与外特性试验及油膜试验结果能够较好地吻合,验证了多面体网格在单叶片螺旋泵数值计算方面的精度;通过对单叶片螺旋泵内部流场的剖析,发现了叶片进口附近存在泄漏流动,泄漏流的强度随流量的增大而逐渐减小;在3个流量工况(0.6Q_d,1.0Q_d和1.4Q_d)下,叶片吸力面出口附近的轮毂表面存在严重的回流现象,而在0.6Q_d工况时,该回流区域占据了流道宽度的80%以上;在叶片压力面与轮毂的交界处也存在多处回流,流量越小,回流越严重;3个工况下,蜗壳出口均存在较大的速度梯度.The flow field in a submersible screw centrifugal pump of 240 specific speed with singleblade is studied by using numerical simulation and experimental observation. The pump fluid domains are meshed by using polyhedral cells and the steady turbulent flow in them are calculated by employing the Realizable k-ε turbulence model. The predicted performance curves are compared with measurements,and the simulated flow field in the impeller is examined against the flow pattern in oil film visualization. It is shown that the predicted characteristic curves agree well with the measurements and the calculated streamlines on the impeller flow passage walls are consistent with the oil film observations,suggesting the polyhedral mesh has a better accuracy in flow simulations of the impeller in a screw centrifugal pump. Through an analysis of the internal flow field,a leakage flow around the bladeinlet is captured,but it becomes weak gradually with the increasing of flow rate. Moreover,under the working conditions of 0. 6Q_d,1. 0Q_d and 1. 4Q_d,there exists a severe backflow on the hub surface near the blade suction side around the impeller outlet; especially,at 0. 6Q_d flow rate,the backflow has occupied an area as large as more than 80% the flow channel width. A backflow also exists in the corner between the blade pressure side and the hub; the smaller the flow rate are,the more serious the backflow. Under these three working conditions,there exists a larger gradient in the velocity at volute outlet.

关 键 词：单叶片螺旋离心泵 流场 油膜试验 多面体网格 二次流 

分 类 号：S277.9[农业科学—农业水土工程] TH312[农业科学—农业工程]