Inlet Boundary Conditions for Numerical Study of Hydrodynamics in Bubbling Fluidized Beds

The inlet boundary condition is one of the most important factors that influence the dynamics of bubbling fluidized beds. A constant inlet gas velocity boundary condition (CIGVBC) and an oscillating inlet gas velocity boundary condition (OIGVBC) are used to investigate the effect of the inlet boundary condition on the hydrodynamics of gas-solid two-phase flows in bubbling fluidized beds. Numerical studies on gas-solid two-phase flows in bubbling fluidized beds are carried out based on an Euler-Euler two-fluid model. The size and frequency of the bubbles are carefully analyzed in this work. Numerical results obtained here are compared with the experimental results of Kuipers et al. (1991) and Mori and Wen (1975). The numerical study indicates that an oscillating inlet gas velocity in bubbling fluidized beds predicts the behavior of the flow more accurately than that with a constant inlet gas velocity.