Natural Convection in Fluid/Porous Region Heated from Below with Conductive Partition

Abstract

DOI: 10.2514/1.T3660 A numerical study has been made of natural convection in an enclosure heated from below with a conductive partition. The upper and lower regions are filled with pure fluid and a fluid-saturated porous medium, respectively. Two-dimensional Navier–Stokes-equation and non-Darcian models (including inertia, boundary, and convective effects) govern the fluid region and the porous region. The major parameters of the problem are fluid Rayleigh numberRa,partitionlocationheightratio(denotedHR),aspectratioA,porosity ,conductivityratioofthepartition tothe fluid(denotedKR),andconductivityratioofthe fluid/porousmatrixtothe fluidke=kf.Theresultsindicatethat the partition location and thermal conductivity significantly influence the heat transfer rate. Lower HR (a thinner porous region) and higher thermal conductivity ratio KR possess a higher heat transfer rate and intensify the occurrenceoftheonsetofconvection.Inaddition,highporosityandhigheffectivethermalconductivityintheporous mediumcanincreasetheheattransferrate.TheincreaseofNuisabout35 � 41%,withincreaseofke=kf from1–5for porosity ranging from 0.4–0.6.