为获得旋流泵内更为符合物理真实的液固两相流动特征,在传统欧拉(Euler)双流体模型基础上加载群体平衡模型(PBM),以考虑实际存在的颗粒聚并、破碎等动力学行为,与CFD耦合计算了不同流量、颗粒粒径及浓度下的液固两相流场,分析了颗粒存在对泵外特性的影响规律.计算结果表明:从进口到出口,叶片背面附近颗粒粒径明显增大;在叶轮出口位置,同一半径上,从叶片工作面到背面附近存在粒径梯度;在外缘部,沿轴向形成粒径梯度.与Euler模型计算结果对比发现:加载PBM模型后,颗粒总体浓度分布特征存在差异;同一轴截面上,颗粒浓度在中心部的分布基本相同,而在中间和外缘部位置出现差异.PBM模型计算得到的泵扬程、效率曲线更接近于实验值,证明基于CFD一PBM耦合计算的预测精度更符合实际.
in order to obtain physical reality of liquid-solid two-phase flow characteristics in a vortex pump,ased on the Euler- Euler two fluid model,loading population balance model (PBM). Considering particle dynamics behavior of coalescence and breakage, calculating liquid-solid two-phase flow field under different flow rate, particle size and volume concentration of particles, and pump performance variation with particles. Calculation results show that:From import to export, particle size near the back of the blade increases significantly;in impeller exit location, the same radius, from the blade to near the back form reverse diameter gradient;in the outer section,forming reverse diameter gradient in the direction of axial. Comparing with Euler-Euler two fluid model results, after loading PBM model,the total particle concentration distribution characteristic exist differences;in the same shaft section,the distribution of particle concentration is basically the same in the center;but in the middle and out edge location appear difference. PBM model to calculate the pump head and efficiency is more closer to the experimental value, proving that CFD-PBM coupled calculation of prediction accuracy is higher.