LAUSR

Numerical simulations of three-phase gas-liquid-particle flows under 1g and 2g gravitational conditions were performed with an Eulerian-Lagrangian method. In this study, the liquid was treated as continuous phase and modeled by a volume-averaged system of governing equations. Bubbles and particles were modeled as discrete phases using Lagrangian method. Drag, lift, buoyancy, and virtual mass forces were included in the Lagrangian equation. Bubbles were treated as spherical without shape variations. The two-way coupling between bubble-liquid and particle-liquid were included and interactions between bubble-bubble and particle-particle were considered with the hard sphere model. Particle-bubble interactions and bubble coalescences were also included in the analysis. The results under 1g normal gravity condition were compared with the available experimental data in earlier simulation with good agreement. The transient flow characteristics of the three-phase flow under 1g and 2g gravitational condition were studied and the effects of gravity were analyzed. The results show that gravity has magnificent effect on the flow characteristics of three-phase gas-liquid-particle flows in bubble columns. The three-phase velocities under higher gravity are larger than that of the flow under normal gravity. The flow under higher gravity develops fast. Bubbles and bubble volume fraction in the higher gravity flow are smaller.