颗粒浓度对高比转速离心泵非定常特性的影响

为了分析颗粒浓度对高比转速离心泵非定常特性的影响,采用Mixture混合多相流模型,利用CFX软件进行数值模拟,分析了不同颗粒浓度时的瞬时湍动能、压力脉动及径向力。研究表明:随着颗粒浓度的增加,效率有所下降,清水条件下的离心泵效率最优;随着颗粒浓度的增大,叶轮内的瞬时湍动能明显增强,叶轮流道内及隔舌处的压力值均减小,脉动幅值均增大,作用在叶轮上的径向力会增大,而作用在隔舌处的径向力会减小;在不同颗粒浓度下,叶轮流道内的压力脉动主频均出现在转频处;隔舌处的压力脉动主频出现在叶频处;叶轮流道内、隔舌处的压力值和压力脉动幅值增减速度快慢的分界点和叶轮上、隔舌处的径向力增减速度快慢的分界点均在颗粒浓度为1%附近。

Effect of Particle Concentration on Unsteady Characteristics of Centrifugal Pump with High Ratio Speed

In order to explore the effect of particle concentration on the unsteady characteristics of centrifugal pump with high ratio speed,this paper uses mixture multiphase flow model,and CFX Simulation software to simulate the fixed liquid two phase unsteady turbulence of centrifugal pump with high ratio rotational speed and different particle concentration,and the instantaneous turbulent kinetic energy,pressure pulsation and radial force of centrifugal pump with different particle concentration are analyzed.The results show that with the increase of particle concentration,the efficiency decreases and the efficiency of centrifugal pump under clean water condition is optimal.With the increase of particle concentration,the instantaneous turbulent kinetic energy in the impeller is clearly enhanced,the pressure in the blade rotation channel and the tongue septum decreases,the pulsating amplitude increases,the radial force acting on the impeller increases,and the radial force acting on the diaphragm decreases.At different particle concentrations,the main frequency of the pressure pulsation in the leaf rotation channel appears at the frequency shift,and the main frequency of the pressure pulsation at the septum is located at the chunking.Among them,the transition points of the pressure value of the blade rotation channel,the pressure pulsation amplitude,and the velocity,along with the transition points of the radial force on the impeller and the septum are all located near the particle concentration of 1%.