基于固液两相流的离心泵内部流场数值分析

Numerical Analysis of Internal Flow in Centrifugal Pump based on Solid-liquid Two-phase Modeling

为了初步研究泥沙颗粒直径对离心泵性能及内部流场的影响,本研究采用particles粒子模型对某离心泵进行全流道数值模拟实验。重点分析了在相同泥沙颗粒体积分数和不同来流泥沙颗粒直径下叶片表面的泥沙颗粒的体积分数分布、泥沙颗粒速度分布的情况。结果表明:由于固体的存在使得流动不稳定,同一离心泵在固液两相流介质下运行较单相流介质会不同程度使泵扬程和效率下降,在相同工况下,随着泥沙颗粒直径的增加,叶片表面泥沙颗粒体积分数上升,且有向压力面偏移的趋势,叶片表面泥沙颗粒速度也逐渐增大;导致叶片进水边、叶片吸力面出水边磨损较为严重。该研究可为以含沙水为工作介质的离心泵设计提供一定的参考。

Topreliminarily study the influence of sediment particle diameter on the internal flow field and performance in centrifugal pump,a numerical simulation with the whole flow passage of centrifugal pump was performed based on solid-liquid two-phase flow model. With the same volume fraction of sediment particles,the distribution of sediment particle volume fraction and the velocity distribution of sediment particles were studied for different incoming flows.It was found that the presence of solids makes the flow unstable,and solid-liquid two-phase can decrease the head and efficiency of centrifugal pump compared with single-phase to a certain extent. Under the same operating conditions,with the increase of the diameter of sediment particles,the volume fraction of sediment particles on the surface of the blade increases,and there is a tendency to shift to the pressure surface of blade,and the velocity of the sediment particles gradually increases. There are more serious wears at inlet and the suction surface of outlet. This study is believed to serve as a reference for the design of centrifugal pump with sand-laden water as working medium.