粗糙颗粒碰撞参数对鼓泡流化床内气固流动模拟的影响

结合粗糙颗粒动力学理论和双流体方法，数值模拟了碰撞参数对鼓泡流化床内稠密气固两相流动特性的影响. 结果表明，增大摩擦系数或减小法向弹性恢复系数会使床内颗粒分布更为不均，并增强床层膨胀及压力降脉动. 合理选取摩擦系数模拟得到时均气固流场分布，与实验吻合，罂粟籽颗粒的摩擦系数取0.3~0.6较合适. 法向弹性恢复系数改变不影响时均气固流场分布的基本形态，其取值敏感性不如摩擦系数；切向弹性恢复系数对鼓泡流化床动态特性及时均气固流场的影响相对较弱.

Effects of Collisional Parameters of Rough Particles on Simulation of Gas-Solid Flow in a Bubbling Fluidized Bed

A two-fluid model based on the kinetic theory of rough particles was used to study the effects of collisional parameters on the flow behaviors of gas and particles in a bubbling fluidized bed. It was found that increasing the friction coefficient or decreasing the normal restitution coefficient led to more heterogeneous distribution of particles, larger expansion of the bed surface and more intense fluctuation of gas pressure drop. The time-averaged gas-solid flow fields predicted with a proper friction coefficient agreed well with the experimental data, and the friction coefficient was recommended at 0.3~0.6 for the poppy seeds. But the variation of normal restitution coefficient did not change the overall time-averaged flow fields, so its value was less sensitive than the friction coefficient. The tangential restitution coefficient had comparatively much weaker impact on both the dynamic characteristics of the bubbling fluidized bed and the time-averaged gas-solid flow fields.