Parallel LES-DEM simulation of dense flows in fluidized beds

Abstract

This paper exhibits a parallelization strategy for the Discrete Element Method (DEM) applied to simulate dense flows in fluidized beds and combined with the Large-eddy Simulation (LES). The gas phase is parallelized by spatial decomposition techniques whilst “ghost domain” technique is used for particles. The parallelization strategy is tested and the proposed LES-DEM coupling approach is validated. The results demonstrate that the parallelization strategy shows excellent accuracy, good stability and high efficiency as the processors increase both in a small scale pseudo two-dimensional (2-D) and a large scale three-dimensional (3-D) bubbling fluidized bed. Numerical results show good agreements with the experimental data in simulating a circulating fluidized bed riser. Moreover, the gas-solid motions and the closed loop pressure distribution in a 3-D full-loop circulating fluidized bed are accurately captured, demonstrating the promising applications of the proposed model in dense flows simulations of fluidized beds with complex geometries and across wide fluidization regimes.