A Problem about Soil Moisture and Temperature Changes in a Case of Finite Soil Type for an Airtight Container

A study of simultaneous transfer of heat and moisture in a soil (I)

Abstract

In this paper, a comparison of experimental and numerical analyses is made regarding the problem of the simultaneous transfer of heat and moisture of a sandy soil for an airtight cylindrical container.
Befor calculation and discussion the following items are made clear: a few physical properties of the soil, thermal conductivity and hydraulic diffusion coefficient versus soil moisture content and order of correction factor of vapor flux in the soil (the authors reported before that the order would be kept almost constant in capillary potential of the soil water).
Consequently, in the soil moisture distribution measurements clearly exist processes of both sorption and desorption. It is found in all domains of the measured distribution that the calculated distribution with hydraulic diffusion coefficient of the sorption process is in good agreement with the measured distribution in the domain of the sorption process only, but not with that in the domain of the desorption process. This fact gives a good evidence to the recent report that the hydraulic diffusion coefficient in the desorption process tends to become smaller at the same moisture content than that in the sorption process.
Calculated temperature distribution is in good agreement with measured one.
In the last section of this paper, the correction factor of vapor flux by thermal gradientis obtained from the steady state data about the measured distributions of soil moisture and temperature.