关键词: 动力学理论, 数值模拟, 两相流, 弹性恢复系数, 摩擦系数

Abstract: 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.

Key words: kinetic theory, numerical simulation, two-phase flow, restitution coefficient, friction coefficient