Transient Natural Convection From a Vertically Embedded Heat Source in a Thermally Stratified Porous Layer

Numerical results are presented for transient natural convection from a heat source vertically embedded in a saturated porous layer. The porous layer is initially thermally stratified with a negative temperature gradient. The effects of the source strength and its buried depth on the penetration of convective flows are investigated. The results, which include the buoyancy-induced flow patterns and temperature profiles, as well as the heat transfer coefficient in terms of the Nusselt number, are presented for a wide range of base Rayleigh number and stratification parameter. The results thus obtained have important implications for applications in geothermal energy and underground disposal of nuclear wastes.