Effect of periodic surface temperature on heat transfer in layered saturated soil

This paper presents numerical analyses of one-dimensional heat transfer in layered saturated soil with effective porosity and under a periodic temperature boundary condition using the numerical model HT1. The model characterizes the soil layer using separate columns to represent solid matrix and mobile pore fluid components, and a series-parallel approach to model soil thermal conductivity. Numerical simulations are presented to illustrate the effect of fluid velocity, thermal retardation factor, thermal conductivity of solid particles, effective porosity and layer heterogeneity. Numerical results indicate that increasing downward fluid velocity and decreasing retardation factor can increase the distance that temperature oscillations from the surface can propagate into the layer. In addition, decreasing fluid velocity, increasing retardation factor, and increasing thermal conductivity of solid particles can decrease the temperature oscillation amplitude in the soil. Temperature profiles also indicate the significance of soil effective porosity and multiple soil layers on heat transfer behavior.