NATURAL CONVECTION IN CONFINED CYLINDRICAL ENCLOSURE OF POROUS MEDIA WITH CONSTANT AND PERIODIC WALL TEMPERATURE BOUNDARY CONDITIONS
محتوى المقالة الرئيسي
الملخص
Numerical investigations of unsteady natural convection heat transfer through a fluid-saturated porous
media in inclined cylindrical enclosure are studied by solving the governing (3-D) Darcy-Boussinesq
equations using finite difference method. The momentum equation of flow was solved by Relaxation method and the energy equation by using Alternating Direction Implicit (ADI) method. The problem is analyzed for modified Rayleigh number with range of (50-300),angles of inclination (0°,25°,45°60°90°), amplitude of sinusoidal temperature (0.2, 0.4, 0.8) and period (0.005, 0.01, 0.02). Results indicate an increase in the heat transfer with increasing of Rayleigh number, time, amplitude, angle of inclination and period. Also average and local Nusselt number were calculated and it is found that Maximum temperature and velocity occur at angle α=45 and this indicate a strong buoyancy force effect on convective flow.
تفاصيل المقالة
القسم
كيفية الاقتباس
المراجع
Bejan, A.; ''Convective Heat Transfer'', Wiley, New York, 1984.
• Hiroyuki O., and Tsutomu S., 1981''Natural Convection in Inclined Circular Cylindrical Annulus Heated and Cooled on its End Plates'', Int. J. Heat Mass Transfer, Vol.24, No. 4, pp.727-737.
• Iyer, S. V. and Vafai, K.; ''Passive Heat Transfer Augmentation in a Cylindrical Annulus Utilizing a Porous Perturbation'', Numerical Heat Transfer, Part A, 36, PP.115-128, 1999.
• Mohammad, A. A. and Saeid, N. H.; ''Natural Convection in a Porous Cavity with Spatial Sidewall Temperature Variation'', Int. J. of Numerical Methods for Heat and Fluid Flow, Vol.15, No.6, PP.555-566, 2005.
• Mohammad, M. S.; ''Natural Convection in Confined Cylindrical Enclosure of Porous Media with Constant and Periodic Wall Temperature Boundary conditions'', M.Sc. Thesis, University of Baghdad, 2008.
• Shivakumara, I. S., Prasanna, B. M. R. Rudraiah, N. and Venkatachalappa, M.; ''Numerical Study of Natural Convection in a Vertical Cylindrical Annulus Using Non-Darcy Equation'', J. of Porous Media, Vol.5, No.2, PP.87-102, 2002.
• Wang, B. X. and Zhang; ''Natural Convection in Liquid-Saturated Porous Media between Concentric Inclined cylinder'', Int. J. Heat Mass Transfer, Vol.33, PP.827-833, 1990.
• Wajeeh, K. H.; ''Transient Three-Dimensional Natural Convection in Confined Porous Media with Periodic Boundary Conditions'', PhD. Thesis, University of Technology, 2006.