Abonnement à la biblothèque: Guest
Portail numérique Bibliothèque numérique eBooks Revues Références et comptes rendus Collections
Journal of Porous Media
Facteur d'impact: 1.752 Facteur d'impact sur 5 ans: 1.487 SJR: 0.43 SNIP: 0.762 CiteScore™: 2.3

ISSN Imprimer: 1091-028X
ISSN En ligne: 1934-0508

Volumes:
Volume 23, 2020 Volume 22, 2019 Volume 21, 2018 Volume 20, 2017 Volume 19, 2016 Volume 18, 2015 Volume 17, 2014 Volume 16, 2013 Volume 15, 2012 Volume 14, 2011 Volume 13, 2010 Volume 12, 2009 Volume 11, 2008 Volume 10, 2007 Volume 9, 2006 Volume 8, 2005 Volume 7, 2004 Volume 6, 2003 Volume 5, 2002 Volume 4, 2001 Volume 3, 2000 Volume 2, 1999 Volume 1, 1998

Journal of Porous Media

DOI: 10.1615/JPorMedia.v12.i11.50
pages 1083-1100

Numerical Analysis of Natural Convection in Porous Cavities with Partial Convective Cooling Conditions

Watit Pakdee
Dept. of Mechanical Engineering, Dept. of Mechanical Engineering Faculty of Engineering Center for R&D on Energy Efficiency Thermo-Fluid Systems (CETF) Center of Excellence in Electromagnetic Energy Utilization in Engineering (CEEE), Thammasat University, Rangsit Center Pathumtani, Thailand Faculty of Engineering Center for R&D on Energy Efficiency Thermo-Fluid Systems (CETF), Center of Excellence in Electromagnetic Energy Utilization in Engineering (CEEE), Thammasat University, Rangsit Center Pathumtani, Thailand
P. Rattanadecho
Faculty of Engineering, Thammasat University (Rangsit Campus), Pathumthani 12121

RÉSUMÉ

Transient natural convection flow through a fluid-saturated porous medium in a square enclosure with a partially cooling surface condition was investigated using a Brinkmann-extended Darcy model. The physical problem consists of a rectangular cavity filled with porous medium. The cavity is insulated, except the top wall that is partially exposed to an outside ambient. The exposed surface allows convective transport through the porous medium, generating a thermal stratification and flow circulations. The formulation of differential equations is nondimensionalized and then solved numerically under appropriate initial and boundary conditions using the finite difference method. The finite difference equations handling the convection boundary condition of the open top surface are derived for cooling conditions. In addition to the negative density gradient in the direction of gravitation, a lateral temperature gradient in the region close to the top wall induces the buoyancy force under an unstable condition. The two-dimensional flow is characterized mainly by the clockwise and anti-clockwise symmetrical vortices driven by the effect of buoyancy. The directions of vortex rotation generated under the cooling condition are in the opposite direction as compared to the heating condition. Unsteady effects of associated parameters were examined. The modified Nusselt number (Nu) was systematically derived. This newly developed form of Nu captures the heat-transfer behaviors reasonably accurately. It was found that the heat-transfer coefficient, Rayleigh number, Darcy number, as well as flow direction strongly influenced characteristics of flow and heat-transfer mechanisms.


Articles with similar content:

MIXED CONVECTION IN A 90° HORIZONTAL BEND
International Heat Transfer Conference 10, Vol.14, 1994, issue
J.J.M. Sillekens, Anton A. van Steenhoven, Camilo C. M. Rindt
EFFECTS OF RADIATION, VISCOUS DISSIPATION, AND MAGNETIC FIELD ON NANOFLUID FLOW IN A SATURATED POROUS MEDIA WITH CONVECTIVE BOUNDARY CONDITION
Computational Thermal Sciences: An International Journal, Vol.8, 2016, issue 2
B. Shankar, Eshetu Haile
SORET AND DUFOUR EFFECTS ON MHD NATURAL CONVECTIVE HEAT AND SOLUTE TRANSFER IN A FLUID-SATURATED POROUS CAVITY
Journal of Porous Media, Vol.19, 2016, issue 8
Naikoti Kishan, Ali J. Chamkha, Balla Chandra Shekar
Mixed Convection Boundary Layer Flow of a Micropolar Fluid Along a Vertical Cylinder
International Journal of Fluid Mechanics Research, Vol.33, 2006, issue 3
Harmindar S. Takhar, Ali J. Chamkha, Rama Subba Reddy Gorla
VISCOUS DISSIPATION AND OHMIC HEATING EFFECTS ON MAGNETOHYDRODYNAMIC MIXED CONVECTION ALONG A VERTICAL MOVING SURFACE EMBEDDED IN A FLUID-SATURATED POROUS MEDIUM
Journal of Porous Media, Vol.13, 2010, issue 2
Ahmed M. Rashad, Rama Subba Reddy Gorla, Ahmed Y. Bakier