A Mesoscopic Approach for Evaporation in Capillary Porous Media

Abstract

Mathematical modelling of evaporation process in capillary porous media is commonly addressed using two approaches: Continuum models (CMs) derived within the framework of the volume averaging technique and pore network models (PNMs) developed on the basis of invasion percolation concepts. Though widely used, CMs are unable to adequately describe the microstructure of porous media and the relevant physics such as fractal behaviour. PNMs however overcome such limitations by approximating the pore structure of porous media and by formulating conservative transport equations for individual phases at the pore scale. Despite these advantages, PNMs cannot truly resolve the details of the void space geometry and they also bypass individual pore-scale effects. These shortcomings can be overcome by using the lattice Boltzmann method (LBM) which has recently become a popular technique for simulating multiphase flow in porous media. In LBM the void space is precisely described and the averaged intermolecular forces are accommodated. In this chapter, we present a multiphase lattice Boltzmann method called Shan Chen LBM for simulating pore-scale physics and micro-macro interactions during evaporation process in capillary porous media.