Heat and Moisture Transfer in a Partly Frozen Nonheaving Soil

Abstract

AbstractThe purpose of this research was to develop a computer model to simulate water and heat movement in the soil under freezing conditions. The model was based on the theory of coupled heat and mass transport, which was derived from the theory of irreversible thermodynamics. A finite difference scheme was used to solve the coupled‐fluxes equations in space. The difference scheme used only first‐order derivatives to facilitate the simulation of steep gradients of hydraulic potential at the freezing front. The simulated results were compared against two sets of laboratory experiments in which soil columns were suddenly cooled below freezing at one end. Thermal and hydraulic soil properties used in the simulation model were either obtained from independent measurements on the soil or by well‐established estimating procedures. The simulated results agreed well with the observed values in the first experiment, and in the second experiments the simulated data followed the trend, but a too low ice content was predicted and the freezing front prediction lagged behind. Overall it seems that although the model in its present form is limited to nonheaving conditions, the theory of irreversible thermodynamics is a promising approach to simulate heat and moisture transfer in partly frozen soils.