DEM-CFD study of the filter cake formation process due to non-spherical particles
The formation of a filter cake during the filtration of a suspension with non-spherical particles is studied using a multi-sphere model in a simulation that couples the discrete element method with computational fluid dynamics. The implementation of the coupling with a drag model that considers orientation, sphericity, and the presence of surrounding particles for non-spherical particles is tested for single particles and suspensions by comparing the terminal velocities with empirical results. Phenomena predicted in the simulations, such as the presence or absence of initial oscillations and changes in the orientation of a particle, are consistent with experimental observations reported in the literature. The variation in the void fraction of a filter cake with respect to the particle sphericity is obtained and compared with experimental trends reported in the literature. Furthermore, complex interdependencies of the particle sphericity, void fraction, and pressure drop of a filter cake for a wide range of fluid conditions are investigated.