FDM FORMULATION OF THE COUPLED THERMO-HYDRAULIC FLOW PROBLEM IN UNSATURATED POROUS MEDIA

Karla B. Souza¹; Christianne de L. Nogueira¹

¹ Universidade Federal de Ouro Preto

doi:10.20906/CPS/CILAMCE2017-0173

Resumo

The moisture and heat flows in unsaturated porous media involves the flow of liquid water, vapor of water and adsorbed water, and the heat flow (latent heat, heat of wetting, conduction and convection). The mathematical model which represents this physical phenomenon include the moisture and heat flows equations, by guarantee the mass and energy conservation, taking into account the hydraulic and thermodynamic principals that describes the equilibrium between the liquid phase (liquid water and dissolved air) and gas phase (dry air and vapor of water). This paper presents a generalized formulation of the coupled thermo-hydraulic flow problem which represents the equilibrium equation of the moisture and heat flows in undeformable porous media in thermic equilibrium between the phases. The formulation considers water pressure, gas pressure and temperature as primary variables. This paper also, brings the finite difference method formulation for this problem in unidimensional condition in order to modeling flow process in the interface soil-atmosphere considering the environmental boundary condition (precipitation, evaporation and evapotranspiration).

Palavras-chave: thermo-hydraulic coupling; finite difference methods; unsaturated soil