基于CFD的发动机冷却水泵汽蚀性能预测  

Cavitation performance prediction of engine cooling water pump based on CFD

作　　者：李伟[1] 施卫东[1] 张华[1] 裴冰[1] 陆伟刚[1] 

机构地区：[1]江苏大学流体机械工程技术研究中心,江苏镇江212013

出　　处：《排灌机械工程学报》2012年第2期176-180,共5页Journal of Drainage and Irrigation Machinery Engineering

基　　金：江苏省自然科学基金资助项目(BK 2011505);江苏高校优势学科建设工程项目;江苏省研究生创新计划项目(CX09B_196Z)

摘　　要：以雷诺时均N-S方程为基本控制方程,采用标准k-ε双方程湍流模型及多相流模型,利用计算流体动力学软件CFX模拟了发动机冷却水泵内部的三维湍流流场,对某一叶轮严重损坏的发动机冷却水泵外特性性能和汽蚀性能进行预测,并分析叶轮损坏原因,观察冷却水泵叶轮内部汽蚀情况.模拟结果表明:在85℃下模型泵的临界汽蚀余量约为10.7 m,在表压为0时已发生了较为严重的汽蚀现象,叶轮破坏主要是由汽蚀引起.通过与试验数据进行对比验证,水泵在285 L/min设计流量下扬程为6.1 m,远远低于常温下的数值模拟结果,说明该泵在实际运行工况下已发生严重汽蚀,试验结果与数值预测结论基本吻合.研究结果对于改善发动机冷却水泵的汽蚀性能、防止和减轻空化现象产生提供理论依据,也为判断和模拟发动机冷却水泵的汽蚀破坏提供了一个快速、准确的计算方法.which has The three-dimensional turbulent flow in an engine cooling water pump with the impeller, ever been severely damaged in operation, was simulated employing the time-averaged N - S equations, the standard k -ε turbulence model and multiphase flow model by CFX software. The charac- teristics and cavitation performance were predicted and the reasons for the impeller damage were clarified by observing the flow variable distributions in the impeller of the pump. The numerical simulation results indieat that the critical NPSH of the pump is about 10.7 m at 85 ℃, and a serious cavitation occurs un- der zero gauge pressure, it is suggested that cavitation causes the impeller damage. The experimental head of the pump is 6.1 m at the design flow rate of 285 L/min, it is well below the numerical simulation head under room temperature, thus a serious cavitation has occurred in the real operating conditions; such a conclusion based on the predicted results is basically consistent with the experimental observations. The numerical results provide a theoretical basis for improving the cavitation performance or preventing from or mitigating cavitation in an engine cooling water pump. It offers a fast and precise eomputational method for simulating and identifying cavitation damage in engine cooling water pumps as well.

关 键 词：发动机冷却水泵 汽蚀性能 三维湍流流场 临界汽蚀余量 性能预测 

分 类 号：S277.9[农业科学—农业水土工程] TH313[农业科学—农业工程]