Multiscale Approach for Particulate Flows, Application to Fluidized Beds

In this paper, a discrete element method (DEM) coupled with computational fluid dynamics (CFD) and a distributed Lagrange multiplier - fictitious domain method (DLM-FD) are used is order to model three-dimensional fluidized beds. Particle-particle and wall-particle contacts are handled thanks to a soft sphere model. For the DEM-CFD model, also called Euler-Lagrange model, fluid dynamics variables are locally averaged and solved on a grid larger than the particle size whereas for the DLM-FD grid cells are around 20 times smaller than the particle characteristic length. The aim of this work is to extract information from DLM-FD simulations to improve the correlations used in the DEM-CFD model. First, particles and fluid equations are presented for the Euler-Lagrange model. Then, fluid-particle interaction is detailed. Eventually, we present preliminary simulations and results with both models in a 3D fluidized bed configuration.