基于Lagrange算法的熔盐泵叶轮内稀疏颗粒的跟随性分析

Analysis on tracing characteristics of sparse particles in impeller of molten salt pump based on Lagrange algorithm

基于固液两相流理论,分析了熔盐泵叶轮内结晶颗粒的受力情况,并对颗粒在Lagrange坐标下的运动方程进行了解析计算。运用离散相模型(DPM)对熔盐泵内部流动进行了数值模拟,并将模拟结果与解析解进行比较,讨论了颗粒的跟随性与颗粒直径、颗粒和叶轮的相对位置的关系。结果表明:解析解与数值模拟得到的颗粒跟随性具有较好的一致性;颗粒的周向跟随性优于径向;随粒径的增大,颗粒径向和周向的跟随性均明显变差;颗粒的周向跟随性受颗粒位置的影响不大,径向跟随性随颗粒离叶轮中心距离的增大而变差,且吸力面附近的径向跟随性优于压力面附近。研究结果可为预测泵内颗粒的分布及两相流情况下泵性能提供参考。

Based on the theory of solid-liquid two-phase flow, the forces acting on the crystal particles in the impeller of the molten salt pump were analyzed. The kinematic equations of particles under the Lagrangian coordinates were analytically computed. The turbulent flow in the molten salt pump was simulated by a discrete phase model （DPM）.Compared the tracing characteristics obtained by numerical simulation with the analytical solution, the influences of particle diameter and particle position on tracing characteristics were analyzed.Resuhs showed that the numerical solutions agreed well with the analytical ones.The particle tracing characteristic in the circumferential direction was better than that in the radial direction.The tracing characteristics both in the circumferential direction and the radial direction decreased obviously with the increase of the particle diameter. The position of the particles had little effect on the particle tracing characteristic in the circumferential direction.The particle tracing characteristic in the radial direction decreased with the increase of the distance between the particle and the impeller center, and the one near the suction side was better than that near the pressure side.The results could provide a reference for predicting the distribution of the particles and the pump performance in two-phase flow.