关键词:

颗粒旋转, 颗粒动理学, 鼓泡流化床

Abstract:

The flow behavior of bubble and particles in a gas-solid bubbling fluidized bed was simulated by using a two-fluid model incorporating the effect of particle rotations based on the kinetic theory for rapid granular flow of slightly frictional spheres.A simplified model was implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions.Simulations were performed to study the bubble dynamics in a bubbling gas-fluidized bed without and with the consideration of particle rotations.With particle rotation，bubbles were easily formed in the bed，the particle concentrations decreased，and the bed expansion increased.Simulated results indicated that the axial velocities of particles increased，and the translational granular temperature of particles decreased in comparison with the case without particle rotation in the center regime of bed.It was found that the present model with particle rotations better captures the bubble dynamics and time-averaged bed behavior.With the consideration of the effect of particle rotations，the simulated axial velocities and fluctuating velocities of particles were in agreement with literature，and the predicted bubble diameters were close to the calculated results from literatures.

Key words:

颗粒旋转, 颗粒动理学, 鼓泡流化床