关键词: 气固流化床, 离散颗粒模型, 硬球模式

Abstract: The bubbling behavior in a two-dimensional fluidized bed is numerically studied using the discrete particle simulation model. Inter-particle interactions are taken into account, which are described by binary collisions in a hard-sphere model. The interactions between the particulate and continuous phases are modelled by the Gidaspow's drag formula. The particle momentum equations are solved simultaneously with the gas governing equations, and the void fraction is calculated in a particular way. The hash table is introduced to deal with collision events and shortens the computing time. The numerical results indicate that the bubble transverse movements are enhanced by the interaction among bubbles in the fluidized bed. The trajectories and shapes of bubbles are dependent on the static pressure distribution in the bed and bubbles move towards the area with lower pressure and a larger pressure drop. This phenomenon is similar to that in the gas-liquid separate flow.

Key words: gas-solid fluidized bed, discrete particle model, hard-sphere model