Numerical study of water and heat transfer in unsaturated clay-loam soil

This present study is the numerical estimation of the temperature distribution and the water content distribution underground soil under the Mediterranean climate type. We use as input data of ambient temperature, air humidity and solar radiation, average values during 10 years estimated from data supplied by the local meteorological station (Tizi-Ouzou, Northern Algeria, 36°47′59″, North latitude and 4°1′59″, East longitude). A theoretical model, based on heat and water transfer equations, was established for an unsaturated soil submitted to the climatic conditions of this site. The mathematical model established in mono dimensional type, for a semi infinite transfer model, is based on Whitaker theory of heat and mass transfers in unsaturated porous medium (Withaker 1977, 1980) with the hypothesis that air pressure into soil porosity is equal to atmospheric pressure. The equations were discretized according to the finite volume method, which is more adapted for this type of problem, and were solved by the Newton-Raphson iterative method in the environment of Matlab software. The simulations have been done for two typical days (January 15 and May 15). Curves of temperature and water content evolutions in term of depth and time were obtained.