Thermal conductivity of sands

The thermal properties of soils are important in a variety of applications, including the thermal performance of buried pipelines and geothermal heat pumps. A variety of methods exist for the prediction of thermal conductivity based on empirical fits to databases of soil thermal conductivities. In this paper an analytical model will be developed based on unidirectional heat flow through a three-phase soil element. The performance of this model will be validated against a database of 155 test measurements from the published literature. A variety of alternative prediction methods will be tested against this dataset, with the model derived here being shown to be at least as good as the best empirical model while retaining a physical origin.