离心泵叶轮内部湍流动能及耗散率分析

Turbulence Kinetic Energy and Dissipation Rate Analysis of Centrifugal Pump Impellers

本研究基于雷诺时均N-S方程,采用k～ε湍流模型,对标准离心泵叶轮内部湍流进行了数值模拟。采用质量加权平均湍流动能及湍流耗散率的方法,分析发现湍流动能和湍流耗散率沿半径的分布有十分相似的规律;除0.6Qd设计工况,湍流动能和湍流耗散率分布呈现出先增加,随后减小,最后增加的现象;0.6Qd设计工况下,湍流动能和湍流耗散率最大,流体能量损失最为严重,因此从效率方面考虑,应避免泵在小流量工况下运行。

Based on time-average N-S equations and the use of k~ε turbulence model,turbulence kinetic energy and dissipation rate analysis in the standard centrifugal pump is calculated.By using the quality-weighted average turbulent kinetic energy and dissipation rate method,this paper shows that turbulent kinetic energy and dissipation rate distribution along the radius are very similar.Except for 0.6 times of design discharge condition,turbulent kinetic energy and dissipation rate distribution show increase,then decrease and increase finally.Under the low flow rate condition of 0.6 times of design discharge,turbulence kinetic energy and dissipation rate reaches the maximum,so fluid energy loss is the most serious.From efficiency consideration,it should avoid running the pump at low flow rate condition.