Stainless steel wire meshes offer high mechanical strength, corrosion resistance, thermal stability, and versatility through various mesh sizes, weave types, and wire cross-sections. These characteristics make them well suited for filtering highly viscous fluids such as polymer melts, which typically show non-Newtonian behavior. Simulations for flow through wire mesh filters must therefore incorporate this effect to ensure an accurate determination of the fabric’s permeability and predictions of the pressure drop and filter efficiency.

The geometric properties of such fabrics can be parametrized very well, facilitating the performance of microscale computational fluid dynamics (CFD) studies. The microgeometry is reconstructed by modeling individual metal wires and their contact regions using an in-house development from Fraunhofer ITWM (TexMath) [1]. Polypropylene (PP) rheology models then capture the non-Newtonian behavior of the melt. Together, these enable accurate CFD simulations to calculate the expected flow field (and differential pressure) depending on the fluid under consideration (density and viscosity law) and the inflow velocity with another in-house tool (FLUID) [2]. This, in turn, reduces the need for physical prototypes and the associated experimental effort to test the weave design.

The flow simulation is coupled with particle tracking to simulate the separation performance of the fabric. Various rheology models are compared with each other in terms of differential pressure and filter efficiency. In the talk, we present the different models and discuss the corresponding results.