Study of Phase Transition in Freezing Groundе

This paper considers the movement of water and air in freezing and thawing soil, based on the equations of non-isothermal two-phase filtration. In order to achieve this, the equations of mass conservation, two-phase filtration, and heat balance are employed. The proposed one-dimensional mathematical model considers the phase transition in the extended region, the varying filtration properties of the soil, and the filtration of water into the phase transition region. This paper presents several empirical relationships for the intensity of the water-ice phase transition and their verification with experimental data from the literature. Numerical experiments have demonstrated the fulfillment of the physical maximum principle for soil porosity and the formation of a layer of lower permeability in the soil. This affects the absorption capacity of the soil and the distribution of surface and subsurface runoff during spring snowmelt. The proposed mathematical model can be used to simulate melting snow on the surface of frozen ground.