基于颗粒轨道模型的离心泵叶轮泥沙磨损数值预测

基于两相流颗粒轨道模型和Tabakoff磨损模型,对某型号单吸泵进行数值模拟得到不同泥沙条件和不同入口条件下颗粒运动轨迹和磨损规律。不同泥沙条件共设定7组方案,即颗粒质量分数为10%时,颗粒粒径分别为0.01、0.05、0.1、0.5 mm,以及颗粒粒径为0.5 mm时,颗粒入口质量分数分别为2%、5%、8%、10%。结果表明,离心泵叶轮的磨损主要分布在叶片工作面和后盖板;粒径增大,颗粒向叶片工作面进口边的运动速度增加,形成点状的冲击式磨损;粒径减小时,在叶片工作面靠近出口边处逐渐形成条状的擦伤式磨损;颗粒质量分数对磨损率影响十分显著,而对磨损形态和位置没有影响;颗粒在入口分布的均匀度越大,叶轮内磨损形态的分散程度及磨损位置的轴对称性越明显。

Numerical Simulation of Erosion Prediction in Centrifugal Pump Based on Particle Track Model

Centrifugal pumps are widely used in the solid particles and liquid delivery, a number of areas petrochemical, aerospace, energy, irrigation and the like. When transporting sandy water, its internal wear becomes serious, which affects the life of unit. Therefore, the movement of particles in a centrifugal pump was investigated and the wear characteristics were predicted. Based on the two-phase particle track model and the Tabakoff and Grant erosion model, the simulation of a centrifugal pump was conducted to get the particle track and erosion regulation under different sands or inlet conditions. The result demonstrated that erosion was mostly taken place in hub and pressure side of vane in the impeller compared with shroud and suction side. The particle velocity to pressure side of the vane was increased with the raise of particle diameter, which would lead to dot impact erosion compared with large particles near the inlet side. While the strip scratch erosion was taken place at the press side of the impeller near the outlet when particle diameter was small. Moreover, the position and erosion shape were influenced by particle diameter in significant measure. While the erosion rate density was increased with the increase of concentration and the inlet velocity. Furthermore, the distribution of particle at the inlet also had effect on the erosion state, which meant that with the increase of uniformity of particle in the inlet, the erosion morphology turned into dispersed distribution from continuous sheet.