Transient and steady natural convection from a heat source embedded in thermally stratified porous layer

• Published in: International journal of thermal sciences 2010-09, Vol.49 (9), p.1527-1535
• Main Authors: Zhang, J., Subotic, M., Lai, F.C.
• Format: Article
• Language: English
• Subjects: Buoyancy; Computational fluid dynamics; Convection; Convection and heat transfer; Exact sciences and technology; Flows through porous media; Fluid dynamics; Fundamental areas of phenomenology (including applications); Heat sources; Heat transfer; Heat transfer coefficients; Natural convection; Nonhomogeneous flows; Physics; Porous media; Rayleigh number; Thermal stratification; Turbulent flows, convection, and heat transfer; Wastes
• ISSN: 1290-0729; 1778-4166
• DOI: 10.1016/j.ijthermalsci.2010.03.009

Numerical results are presented for transient and steady natural convection from a heat source buried in a saturated, porous layer. The porous layer is thermally stratified with a negative temperature gradient but its corresponding Rayleigh number is not greater than that of the critical value (Ra c = 40). The effects of the size of the heat source and its buried depth are also 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 Rayleigh number and stratification parameter. The results thus obtained have important implications for applications in geothermal energy and underground disposal of nuclear wastes.