多级离心泵整机流场三维非稳态湍流压力脉动特性分析

Characteristic analysis of three-dimensional unsteady turbulent pressure fluctuation in whole flow field of multi-stage centrifugal pump

为了探究离心泵内部非稳态流动引起的压力脉动现象及其特性,以某型多级离心泵为对象,建立了流场三维有限元网格.采用Fluent仿真技术,选用RNG k-ε湍流模型对离心泵流场进行非稳态数值计算,通过设置监测点,得到了不同位置处在每个时间步长下的压力值.运用FFT方法,对叶轮及蜗壳等主要流道监测点的压力脉动进行频谱分析,结果表明叶轮和蜗壳内的压力脉动主要集中在叶频及其倍频处,并且叶轮与蜗壳之间动静干涉对压力脉动有较大的影响.

In order to study the phenomenon and characteristics of pressure fluctuation induced by unsteady flow in a centrifugal pump,a three-dimensional finite element model of flow field was implemented by applying a multi-stage centrifugal pump as an object.The Fluent simulation technology was adopted,and the RNG k-ε turbulence model was applied to carry out unsteady numerical calculation in the whole flow field of centrifugal pump.By setting observation points,the pressure values of different observation points were obtained at each time step.In addition,Define FFT technique was employed to perform spectrum analysis of pressure fluctuation of observation points located at the impeller and volute.The results indicate that pressure fluctuation of impeller and volute is mainly concentrated in the frequency of impeller and its frequency multiplication,and the dynamic and static intervening between impeller and volute allows a larger effect to pressure fluctuation.