Simulating the interaction of electrostatically charged particles in the inflow area of cabin air filters using a fully coupled system

Precise simulations of particulate flow through fibrous filters are essential in order to predict and enhance filtration performances. To run the computation in reasonable time, a continuum approach is commonly used to emulate the air flow. The software GeoDict [1] allows for the simulation of the complete process, ranging from calculating a flow field, tracking particles inside that field to finding collisions with porous filter media. However, this approach completely neglects particle-particle interactions although particles often carry electrostatic charges [2]. Comparing the results of GeoDict to a fully coupled system shows the influence of this simplification. The software ESPResSo [3, 4] uses such a four-way coupling combining a molecular-dynamics-like approach for partricle simulation with an integrated Lattice-Boltzmann fluid dynamics solver. Already for a simple scenario, which represents the filter media as a mesh consisting of cylindrical fibers, significant influences of the full coupling on the particle trajectories and even the collection efficiency can be observed. We decribe the modeling and setup for both approaches and present numerical results for simplified yet meaningful test cases