Numerical Model for Heat Transfer in Saturated Layered Soil with Effective Porosity

Abstract

A numerical model, called HT1, is presented for one-dimensional (1D) heat transfer in saturated incompressible layered soil with effective porosity and steady fluid flow. The model uses a series-parallel approach for heat transfer and accounts for advection, conduction, and thermal mechanical dispersion assuming local thermal equilibrium between solid and fluid phases. The key to HT1 is the definition of separate columns for the solid matrix and mobile pore fluid. The solid matrix column includes the solid phase and immobile pore fluid and consists of fixed elements. The mobile pore fluid column uses Lagrangian element-tracking to follow the fluid motion, which reduces numerical dispersion and simplifies heat transfer to that of dispersive flux between contiguous elements. Development of the HT1 model is first presented, followed by verification checks using available analytical and numerical solutions. Simulation results for several numeric examples are used to demonstrate model performance and the effects of various parameters, including effective porosity and multiple soil layers, on heat transfer behavior for saturated incompressible soil.