Authors: M Sathiyamoorthy S Narasimman
Publish Date: 2011/05/20
Volume: 89, Issue: 3, Pages: 421-
Abstract
Natural convection flow in a differentially heated square enclosure filled with porous matrix with a solid adiabatic thin fin attached at the hot left wall is studied numerically The Brinkman–Forchheimerextended Darcy model is used to solve the momentum equations in the porous medium The numerical investigation is done through streamlines isotherms and heat transfer rates A parametric study is carried out using the following parameters Darcy number Da from 10−4 to 10−2 dimensionless thin fin lengths L p 03 05 and 07 dimensionless positions S p 025 05 and 075 with Prandtl numbers Pr 07 and 100 for Ra = 106 For Da = 10−3 and Pr = 07 it is observed that there is a counter clockwise secondary flow formation around the tip of the fin for S p = 05 for all lengths of L p Moreover when Da = 10−2 the secondary circulation behavior has been observed for S p = 025 and 075 and there is another circulation between the top wall and the fin that is separated from the primary circulation However these secondary circulations features are not observed for Pr = 100 It is also found that the average Nusselt number decreases as the length of the fin increases for all locations However the rate of decrease of average Nusselt number becomes slower as the location of fin moves from the bottom wall to the top wall The overall heat transfer rate can be controlled with a suitable selection of the fin location and length
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