给定转子动力学参数的离心泵内部流体力研究  

Fluid-induced Forces in Centrifugal Pump under Given Rotordynamic Parameters

作　　者：潘中永[1] 陈士星[1] 吴燕兰[1] 张大庆[1] 李彦军[1] 

机构地区：[1]江苏大学流体机械工程技术研究中心,镇江212013

出　　处：《农业机械学报》2013年第7期55-60,66,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金资助项目(50906034;51109096);江苏高校优势学科建设工程资助项目

摘　　要：通过数值模拟和试验,研究了涡动情况下偏心距和涡动频率比对离心泵内外特性的影响。在给定一系列转子动力学参数条件下,采用RNG k-ε湍流模型对包含前后泵腔在内的全流场进行数值模拟,分析了偏心距对离心泵外特性的影响和涡动频率比对离心泵内部流场的影响,研究了离心泵内部流体力的分布情况以及偏心距和涡动频率比对离心泵内部流体力的影响。研究结果表明:随着偏心距的增大,泵高效区范围变窄;流体力的法向分力Fn、切向分力Ft均与涡动频率比ω/Ω近似呈二次函数关系,这种二次函数关系与偏心距大小相关;叶轮受到的流体力主要来源于叶轮内部流体,且叶轮内部流体周向压力分布不均。对于离心泵来说,当ω/Ω>0时,叶轮内的旋涡较少,水力损失较小,对涡动效果有抑制作用;当ω/Ω<0时,叶轮内旋涡较多,水力损失较大,对涡动效果有促进作用。The effect of eccentricity and whirl frequency ratio on the internal and external characteristics of a centrifugal pump was investigated numerically and experimentally. Under a series of given rotordynamic parameters, the RNG k - 8 turbulence model was applied in the simulation of whole flow field including front and back shrouds of pump. The influence of eccentricity on the external characteristics of the centrifugal pump and the impact of whirl frequency ratio on the internal flow field were analyzed. Then the distribution of the fluid-induced forces in the centrifugal pump and the effect of eccentricity and whirl frequency ratio on the fluid-induced forces in the centrifugal pump were investigated. According to the results, it could be drawn that the high efficiency area of centrifugal pump narrows as the eccentricity increases. Normal fluid force component Fn and tangential fluid force component F, were both approximate into a quadratic function relation against the whirl frequency ratio ω/Ω, influenced by the eccentricity. The fluid-induced forces acting on the impeller were mainly generated by the internal fluid of impeller and uneven circumferential pressure distribution inside. In the centrifugal pump, when ω/Ω 〉 0, vortexes within the impeller were less, hydraulic loss was lower and so restrained the whirling motion ; when ω/Ω 〈 0, vortexes within the impeller were more, hydraulic loss was higher and thus promoted the whirling motion.

关 键 词：离心泵 流体力 转子动力学 偏心距 涡动频率比 

分 类 号：TH311[机械工程—机械制造及自动化]