Fine particles dominate the particle number distribution of Arizona dust ISO 12103-1 A2, commonly used for the performance evaluation of fibrous filter media. However, their role in the overall deposit formation process and subsequent filter clogging is not yet fully understood.

In this work, we investigate the influence of the fine particle fraction on the evolution of deposits using a novel three-dimensional hybrid simulation framework, referred to as SEMI-IB. Here, the fluid flow around fiber(s) and deposited particles is solved under steady-state conditions using spatially resolved immersed boundary method (IBM) simulations, while calculating the fluid-particle and particle-particle/fiber interactions during the unsteady deposition phase using one-way-coupled CFD-DEM simulations based on a coarsened and frozen flow-field solution.

Particle deposition on representative filter media segments is studied considering particle systems with and without the fine particle fraction, such that its impact on deposit formation, possible particle rearrangement and onset of clogging can be evaluated. The results are used for the development of a computationally efficient submodel capturing the effect of the fine particle fraction on the dynamic filtration process without resolving its deposition in detail.