TY - GEN

T1 - Natural convection in horizontal fluid-superposed porous layers heated locally from below

AU - Bagchi, Aniruddha

AU - Kulacki, Francis A.

PY - 2010

Y1 - 2010

N2 - This paper reports numerical studies of steady two-dimensional natural convection in fluid-superposed porous layers heated locally from below. The numerical simulation is based on the Darcy-Brinkman-Forchheimer model for the porous layer and focuses on the parametric domain in which the flow is well established, i.e., the overall Rayleigh number is several orders of magnitude larger than the critical value. An emphasis is placed on revealing the effects of two dimensionless parameters on the overall Nusselt number: The porous layer-to-cavity height ratio (η = Hm/H) and the heater-to-cavity base length ratio (δ = LH/L). Calculations cover η = 0.25, 0.5, 0.75, δ = 0.25, 0.5, 1, and overall Rayleigh numbers from 10 3 to 106. For a fixed height ratio, overall Nusselt numbers increase with a decrease in the heater length. For a given heater length ratio, overall Nusselt number increases with an increase in the height of the overlying fluid layer. Recirculating flow is confined primarily to the overlying fluid layer with some penetration into the upper part of the porous layer. The present results represent an extension of the well studied problem of buoyant convection in superposed layers with a fully heated lower surface.

AB - This paper reports numerical studies of steady two-dimensional natural convection in fluid-superposed porous layers heated locally from below. The numerical simulation is based on the Darcy-Brinkman-Forchheimer model for the porous layer and focuses on the parametric domain in which the flow is well established, i.e., the overall Rayleigh number is several orders of magnitude larger than the critical value. An emphasis is placed on revealing the effects of two dimensionless parameters on the overall Nusselt number: The porous layer-to-cavity height ratio (η = Hm/H) and the heater-to-cavity base length ratio (δ = LH/L). Calculations cover η = 0.25, 0.5, 0.75, δ = 0.25, 0.5, 1, and overall Rayleigh numbers from 10 3 to 106. For a fixed height ratio, overall Nusselt numbers increase with a decrease in the heater length. For a given heater length ratio, overall Nusselt number increases with an increase in the height of the overlying fluid layer. Recirculating flow is confined primarily to the overlying fluid layer with some penetration into the upper part of the porous layer. The present results represent an extension of the well studied problem of buoyant convection in superposed layers with a fully heated lower surface.

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U2 - 10.1115/IMECE2010-39604

DO - 10.1115/IMECE2010-39604

M3 - Conference contribution

AN - SCOPUS:84881464660

SN - 9780791844441

T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)

SP - 1571

EP - 1579

BT - ASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010

T2 - ASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010

Y2 - 12 November 2010 through 18 November 2010

ER -