基于颗粒摩擦和碰撞模型的离心泵叶片磨损预测

Wear prediction of centrifugal pump blade based on particle friction and collision model

采用雷诺时均N-S方程、RNGk-ε模型和SIMPLE算法,以含沙水为介质,基于代数滑移混合物模型(algebraic slip mixture model,ASME)对一台单级双吸式离心泵内固液两相流动进行全三维不可压缩定常流动数值模拟,其中转子与定子之间耦合方式采用"冻结转子法"实现.通过对比清水及含沙水介质时泵外特性试验数据与数值模拟结果,验证了数值计算方法的可靠性.基于颗粒摩擦和碰撞模型对固相体积分数分别为5%、10%、15%时叶片工作面和背面摩擦磨损强度和碰撞磨损强度进行预测,结果表明:在同一固相体积分数时,从叶片进口至出口碰撞磨损强度逐渐增大,且工作面大于背面,摩擦磨损强度呈现先增大后减小,又逐渐增大的趋势;随着固相体积分数增大,叶片表面碰撞磨损强度和摩擦磨损强度逐渐增大,摩擦磨损强度沿着整个叶片均大于碰撞磨损强度.

Based on algebraic slip mixture model, using SIMPLE algorithm, taking silt-laden water as medium, and RNG k-e turbulence mode in Reynolds time-averaged Navier-Stokes equation, the full three- dimensional incompressible stationary solid-liquid two-phase flow in a double-suction centrifugal pump was numerically simulated. The ＂frozen rotor method＂ was used to realize the coupling mode of rotor with sta- tor. By means of comparing the external characteristic test data of the pump with fresh or silt-laden water as medium to numeric simulation result, the reliability of the numeric computation method was verified. Based on particle friction and collision model, the wear intensity of friction and collision on blade pressure arid suction surfaces was predicted in the case of different solid volume fractions（5~, 10~, and 15%）. The results showed that when the solid volume fraction was identical the collision wear intensity of suction surface would gradually increase from blade inlet to outlet. And the collision wear of the pressure surface would be more serious than that of suction surface. The friction wear intensity would increase at first then decrease, and then again increase. With solid volume fraction increasing, the wear intensity of friction and collision of blade pressure and suction surfaces would increase and the fraction wear would be more serious than collision wear.