基于能量梯度理论的离心泵内流动不稳定研究

Flow Instability in Centrifugal Pump Based on Energy Gradient Theory

为研究离心泵内部流动失稳机理,对离心泵内三维湍流流场进行数值模拟,得到不同流量工况下的离心泵内部全流场流动参数,并且应用能量梯度方法对计算数据进行处理,获得能量梯度函数K的分布,并基于能量梯度理论对离心泵内部流动的稳定性进行了分析。研究表明,叶轮出口处和蜗舌处是2个最容易激发流动不稳定的关键位置。此外,随着流量的减少,叶轮内的失稳区域从叶轮出口向叶轮进口迁移。

Mechanism of flow instability in a centrifugal pump was studied by using the energy gradient theory. Numerical simulation was performed for the three-dimensional turbulent flow field in the centrifugal pump. The whole flow parameters in the centrifugal pump at different flow rate conditions were obtained from the simulation. The distributions of the energy gradient function K at various flow rates were calculated by using the data of the numerical simulation. According to the energy gradient method,the area with larger value of K caused instability and high turbulence intensity. The results show that instability was easier to be excited near impeller outlet area and volute tongue. In addition,as the flow rate was reduced,the unstable areas moved from the outlet to the inlet of the impeller.