Pore-scale lattice Boltzmann model for heat and mass transfers in frozen soil

Abstract

The water and thermal characteristics of frozen soil will change during the freezing process, leading to frost heave disasters. Traditional macroscopic numerical methods have some difficulty in dealing with water and heat transport problems in frozen soil. The lattice Boltzmann method (LBM) can overcome these limitations by effectively capturing the complex interactions within porous media. In this study, a pore-scale lattice Boltzmann (LB) model was developed to simulate the coupled heat and mass transfer processes in frozen soil. The developed model incorporates a multicomponent multiphase pseudopotential and an enthalpy-based phase transition model. The relative errors of the model were 0.92 % ∼ 8.01 %, 2.46 % ∼ 14.14 %, and 0.02 % ∼ 13.56 % for the water contents at 12 h, 24 h, and 50 h, respectively, indicating that the current LB model can accurately describe the heat and water transfer characteristics in frozen soil. The inclusion of the freezing suction force in the model can reflect the actual water suction and transport process, resulting in variations of water content at different depths in the frozen soil.