Analysis of flow characteristic on bubbling fluidized bed using SPH Method

采用颗粒相光滑粒子(SP)方法对鼓泡床内的空气和颗粒运动进行了数值模拟。在SP方法中，将控制颗粒相流场的偏微分方程组转化为常微分方程组，即拉格朗日型方程。常微分方程组的数值分析比偏微分方程组的数值分析容易得多。此外，拉格朗日分析适用于描述离散粒子的特性。同时求解了Navier-Stokes方程和拉格朗日型方程。并进行了相应的实验。结果表明，计算结果较好地描述了实验的瞬时颗粒位置，使我们能够了解鼓泡床内气泡形成、气泡合并和气泡破裂的机理。

Air and Particle motions in a bubbling fluidized bed are numerically simulated using Smoothed Particle (SP) method for the particle phase. In the SP method, the partial differential equations, which are the governing equations for the flow fields of the particle phase, are transformed to the ordinary differential equations, which are Lagrangian-type equations. The numerical analysis of ordinary differential equations is much easier than that of partial differential equations. Moreover, Lagrangian analysis is suitable for the description of the characteristics of discrete particles. The Navier-Stokes equation and the Lagrangian type equation were simultaneously solved. The corresponding experiments were also performed. It is found that calculated results describe well the experimental instantaneous particle positions, and enable us to know the mechanisms of bubble formation, bubble coalescence and bubble disruption in a bubbling fluidized bed.