Modeling of Filtration Processes with Arbitrary Shaped Particles Using an Immersed-Boundary-Method (IBM)

Filtration processes are a complex combination of deposition and rearrangement of particles and agglomerates of particles on fibres. The small scales of particles and fibres lead to a lot of difficulties in the experimental analysis of filtration processes. On the other hand, numerical methods are mostly bases on a Lagrangian modelling, i. e. treating the particles as a point of mass neglecting its shape. This requires the use of analytical or empirical correlations for drag and adhesion forces which are often only available for spherical particles. Especially in configurations of particle-particle and particle-wall interactions these correlations may lead to deviations. If non-spherical particles should be considered, the Lagrangian method cannot be applied. In this work, the geometry of the particle is volumetrically resolved and is taken into account in the computational grid for the flow calculation. This is achieved by using an Immersed Boundary Method implemented in the open source CFD code . The method is characterized by a determination of the particle forces through an integration of the viscous and pressure forces acting on the surface as well as the adhesion forces over the particle surface between different parts (particles, walls). Besides the detailed presentation of the model and its implementation in , different application areas of the model are presented.