Numerical Simulation of Flow Through Porous Media

Abstract

The filtration process using porous structures (foams, textile structures, granular materials…) is very complicated and its understanding is important for the production of filter materials for a maximum efficiency, low pressure drop, and filter lifetime. To obtain comprehensive information systematic analysis of the structure of the filter media by image analysis of images obtained by optical and electron microscopy, and through micro-tomography were conducted. In particular, it was the characterization of the morphology and structure incl. directional arrangement, fiber diameters, and pore shape as well as porosity. Based on this information, 2D CAD models were created representing the filter medium with the corresponding parameters. Real filter medium was tested on the experimental test device in order to determine pressure drops at different flow rates. These values determined the boundary conditions of the numerical model and the control values for the verification of the model. The result is a numeric model depicting the water flow depending on the depth and the complexity of the filter. The model shows a very good match with the experimental results. It could significantly help to design the structure of the filter media.