叶片式混输泵内气液两相流的数值计算

气液两相流的数值模拟是多相混输技术研究中的一个难点.本文假定混输泵叶轮内为泡状流动,基于雷诺时均N-S方程和气液两相双流体模型,采用SIMPLEC算法,对叶片式混输泵叶轮内部两相三维紊流流场进行了数值计算,分析了水气混合工况下的流场分布特点.对含气率GVF=15%工况下的扬程特性进行了预测并与试验结果进行对比.数值计算结果表明,混输泵叶轮流道采用较小的径向尺寸差能较好地避免离心力所引起的气液分离,防止气堵现象的发生;叶轮进口部分存在的低压旋涡区容易使气体积聚,因此有必要进一步改进叶轮进口区的水力设计.

CFD ANALYSIS OF THE AIR-WATER BUBBLY FLOW IN A MULTIPHASE ROTODYNAMIC PUMP IMPELLER

The numerical simulation of gas-liquid two-phase flow in an impeller of multiphase pumps is formidable and few transient analyses and two-phase flow analyses have been carried out. In this paper, based on the Navier-Stokes equations and the Two-Fluid Model, the air-water bubbly flow in a multiphase rotodynamic pump impeller has been studied through CFD analysis with SIMPLEC algorithm. The drag force and added mass force are considered in this model. By comparing the pump heads through calculation and experiment in the 15% void fraction condition, the reliability of the numerical method is verified. The numerical results demonstrate that the gas blocking phenomenon can be avoided effectively if relatively small radical dimension is adopted in the flow passage, and vortex mainly occurs in the impeller inlet where the gas will be inclined to gather, so the hydraulic design of the inlet region should be improved.