粒径对高比转速离心泵瞬态流动特性的影响

Influence of Particle Size on Transient Flow Characteristics of Centrifugal Pump with High Specific Speed

基于RNG k-ε湍流模型,利用ANSYS软件对一高比转速离心泵进行固液两相流非定常数值模拟,分析颗粒粒径变化对压力脉动、瞬时湍动能以及径向力的影响。结果表明:随着粒径增大,在小流量工况下离心泵效率逐渐降低,而在大流量工况下离心泵效率先增加后降低;在叶轮流道内靠近进口处其压力值先减小后增大,在流道中段及出口段处其压力值不断减小;作用在叶轮上的径向力先减小后增大,对隔舌处径向力影响较小;同一周期内,随着时间增大,叶轮内瞬时湍动能逐渐减小,减小趋势随着粒径的增大而愈发明显;在不同的粒径下,叶轮流道中压力脉动的主频率和隔舌上压力脉动的主频率分别以转频的1倍和叶频的1倍出现。

Based on the RNG k-εturbulence model,the solid-liquid two-phase flow indefinite constant value of the centrifugal pump with high specific speed was simulated by using ANSYS software,and the influences of the particle size change on the pressure pulsation,instantaneous turbulent kinetic energy and radial force were analyzed by changing the particle diameter.The results show that with the increase of particle size,the efficiency of the centrifugal pump decreases gradually under the condition of small flow,but increases first and then decreases under the condition of large flow;the pressure value in the impeller passage near the inlet decreases first and then increases,the pressure value in the middle and outlet section of the flow passage decreases continuously;the radial force acting on the impeller decreases first and then increases,and the radial force at the tongue separation is little effected.In the same period,with the increase of time,the instantaneous turbulent kinetic energy in the impeller decreases gradually,and the decreasing trend is more obvious with the increase of particle size.Under different particle diameters,the main frequency of pressure pulsation in the impeller passage and the main frequency of pressure pulsation at the tongue separation appear at 1 time rotating frequency and 1 time blade frequency respectively.