DNSlab: 3D 1½-Way Coupled CFD-DEM Simulation of Filter Cake Buildup and Backwash

The deposition and backwashing of spherical 10 and 20 µm particles from water at a microfiber nonwoven is simulated with DNSlab. The particle density is the same as the water density. The forward and backward flow velocity is 0.02 m/s. 3 different parameter combinations for the adhesion forces between particles and particles (FP) and between particles and fiber structure (FS) of 1 and 10 nN are used. Red particles contact the fiber structure or other particles, purple means deposited, blue means detached after deposition. The comparison of the videos shows the effect of the adhesion forces on the filtration depth, on the filter cake buildup and on the particle retention at backwashing.