A dual-scale lattice gas automata model for gas-solid two-phase flow in bubbling fluidized beds

摘要

Modelling the hydrodynamics of gas/solid flow is important for the design and scale-up of fluidized bed reactors. A novel gas/solid dual-scale model based on lattice gas cellular automata (LGCA) is proposed to describe the macroscopic behaviour through microscopic gas-solid interactions. Solid particles and gas pseudo-particles are aligned in lattices with different scales for solid and gas. In addition to basic LGCA rules, additional rules for collision and propagation are specifically designed for gas-solid systems. The solid's evolution is then motivated by the temporal and spatial average momentum gained through solid-solid and gas-solid interactions. A statistical method, based on the similarity principle, is derived for the conversion between model parameters and hydrodynamic properties. Simulations for bubbles generated from a vertical jet in a bubbling fluidized bed based on this model agree well with experimental results, as well as with the results of two-fluid approaches and discrete particle simulations.