DEM-CFD modeling of particle systems with long-range electrostatic interactions

Abstract

To investigate dynamic behaviors of monocharged particle systems, a direct truncation (DT) method and a hybrid particle-cell (HPC) method are implemented into the discrete element method coupled with computational fluid dynamics (DEM-CFD) with defined cutoff distances. The DT method only considers electrostatic interactions between particles within the cutoff distance while the HPC method computes electrostatic interactions in the entire computational domain. The deposition process of monocharged particles in a container in air was simulated using the developed DEM-CFD. It was found that using the DT method, the macrostructure, evolution of granular temperature, and radial distribution function of the particle system were sensitive to the specified cutoff distance. In contrast, using the HPC method, these results were independent of the specified cutoff distance, as expected. This implies that, although electrostatic interactions between particles with large separation distances are weak, they should be considered in DEM-CFD for accurate modeling of charged particle systems.