Pore-scale Modeling of Rarified Gas Flow in Micro Fractal Porous Media, Using Lattice Boltzmann Method (LBM)

Due to the widespread use of rarified gas flow in micro porous media in industrial and engineering problems, a pore-scale modeling of rarified gas flow through porous media with fractal geometries is presented using lattice Boltzmann method (LBM). For this purpose, square- and circular-based Sierpinski fractal geometries are selected due to their inherent behavior for real porous media. Diffusive reflection slip model is used and developed for these porous media through this study. With this respect, planar Poiseuille flow is selected as benchmark and validated with literatures. The effect of Knudsen number (Kn) on the permeability and Darcy number (Da) is investigated and compared in each geometry. It is shown that as Knudsen number increases permeability and Darcy number will increase due to the gas slippage effect on the blocks. In addition, it is observed that the permeability and Darcy number are more sensitive to gas flow behavior at slip and beginning of transition flow regimes.

Keywords:

Lattice Boltzmann method (LBM) , Knudsen number , Fractal , Porous media , Pore-scale modeling ,