对角泵叶轮内部流动与能量特性数值分析  

Numerical Analysis of Internal Flow and Energy Performance of Diagonal Impellers

作　　者：朱红耕[1] 张仁田[1,2] 邓东升 姚林碧[2] 魏军[1] 

机构地区：[1]扬州大学水利科学与工程学院,江苏扬州225009 [2]江苏省水利勘测设计研究院有限公司,江苏扬州225009 [3]南水北调东线江苏水源有限责任公司,南京210029

出　　处：《南水北调与水利科技》2008年第5期63-66,共4页South-to-North Water Transfers and Water Science & Technology

基　　金：“十一五”国家科技支撑计划重大项目(2006BAB04A03);水利部“948”项日(200421)资助

摘　　要：利用RNG k-ε紊流模型封闭时均N-S方程组,对一组对角泵叶轮的内部三维流动进行了数值模拟,在分析基本流态的基础上,对对角泵叶轮的能量特性进行了预测和比较。计算结果表明,对应于不同的叶片夹角,对角泵叶轮的能量性能差异很大。轴流泵叶片对角布置后,离心力的作用使对角泵叶轮的扬程提高,使得叶轮的最优比转数随叶片夹角的减小而减小。随着叶片夹角和流量的减小,对角泵叶轮的功率不是增加而是减小,功率特性由轴流泵逐步向离心泵过渡。与对应的轴流泵相比,对角泵的最优效率点向小流量方向偏移,但高效区变宽。叶片夹角为150°的对角泵叶轮的流量加权平均效率比对应的轴流泵叶轮高0.82%。因此,选择优秀的水泵水力模型,通过优化叶片夹角、叶轮室及轮毂的形状和尺寸,能够改善和提高对角泵叶轮的能量特性。The RNG k-ε turbulent model is adopted to close the time-averaged Navier-Stokes equations to simulate the 3 dimentional internal flows of diagonal impellers. By analyzing basic flow patterns of diagonal impellers, their energy performances are predicted and zompared. The results show that there exist great differences in energy performances of diagonal impellers for different diagonal angles of blades. When the blades of axial-flow pump are placed in diagonal, the axial-flow impeller becomes a diagonal impeller and the working heads of the latter are raised by the action of zentrifugal force. The specific speed of diagonal impellers at best efficiency points become smaller. As the decrease of diagonal angle and flow rate of impellers, the power of diagonal impellers is not increased but decreased, and its power characteristics go through an interim from the power characteristics of axial-flow pump to that of centrifugal pump. Compared with the corresponding axial-flow pump, the best efficienzy point of diagonal impellers moves toward the direction of smaller flow rates, and the scope of high efficiency zone becomes wider. The diagonal impeller with 150° blade angle has higher flow-rate weighted efficiency by 0. 82% than that of the corresponding axial-flow impeller. To improve and increase diagonal impeller efficiency, it is proposed to select excellent hydraulic models of pump and aiming at different specific speeds of impellers and features of blades to conduct optimum design of diagonal angles, the shape and size of pump casing and hub.

关 键 词：对角泵 叶轮 基本流态 能量特性 叶片夹角 数值模拟 

分 类 号：TV136[水利工程—水力学及河流动力学]