A pore-scale analysis for friction factor and permeability in confined porous medium with LB method

Abstract

The flow characteristic at a micro-scale level is significant to the development of micro-devices. In this study, a confined porous medium with a slip gas flow was simulated using a multiple relaxation time (MRT) - lattice Boltzmann (LB) method. The gas-solid interface incorporated the velocity slip effect to model the flow behavior in slip regime. A pore-scale porous domain with three different micro-obstacles (circle, ellipse and diamond) were considered in staggered formation. The slip flow over different obstacles was investigated for friction factor coefficient and permeability. Knudsen number, Reynolds number and porosity were varied to obtain the numerical results for the comparison. It was observed that the friction factor coefficient presents a decreasing trend, whereas the permeability is increased for all increasing variables. In the end, a predictive correlation for permeability correction factor was proposed based on the obtained results, which will be valuable to understand the slip flow at a micro pore-scale level.