Numerical Study of Natural Convection in a Vertical Rectangular Enclosure

1969 ◽  
Vol 12 (12) ◽  
pp. II-208 ◽  
Author(s):  
Arthur Rubel
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Rectangular Enclosure

Three-Dimensional Steady and Oscillatory Natural Convection in a Rectangular Enclosure With Heat Sources

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Amin Bouraoui ◽  
Rachid Bessaïh
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Three Dimensional ◽  
Air Cooling ◽  
Heat Sources ◽  
Rectangular Enclosure ◽  
Aspect Ratios ◽  
Simpler Algorithm ◽  
Strong Relation

In this paper, a numerical study of three-dimensional (3D) natural convection air-cooling of two identical heat sources, simulating electronic components, mounted in a rectangular enclosure was carried out. The governing equations were solved by using the finite-volume method based on the SIMPLER algorithm. The effects of Rayleigh number Ra, spacing between heat sources d, and aspect ratios Ax in x-direction (horizontal) and Az in z-direction (transversal) of the enclosure on heat transfer were investigated. In steady state, when d is increased, the heat transfer is more important than when the aspect ratios Ax and Az are reduced. In oscillatory state, the critical Rayleigh numbers Racr for different values of spacing between heat sources and their aspect ratios, at which the flow becomes time dependent, were obtained. Results show a strong relation between heat transfers, buoyant flow, and boundary layer. In addition, the heat transfer is more important at the edge of each face of heat sources than at the center region.

INTERACTION OF WALL CONDUCTION WITH NATURAL CONVECTION FROM HEATED CYLINDERS IN A RECTANGULAR ENCLOSURE

1995 ◽  
Vol 19 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Marcel Lacroix ◽  
Antoine Joyeux
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Vertical Wall ◽  
Complex Function ◽  
Convection Heat Transfer ◽  
Heat Removal ◽  
Thermal Conductivity Ratio ◽  
Bottom Surface ◽  
Rectangular Enclosure ◽  
Vertical Walls

A numerical study has been conducted for natural convection heat transfer for air from two vertically separated horizontal heated cylinders confined to a rectangular enclosure having vertical walls of finite conductances and horizontal walls at the heat sink temperature. The interaction between convection in the fluid filled cavity and conduction in the vertical walls is investigated. Results have been obtained for Rayleigh numbers, Ra, between 103 and 106, dimensionless wall-fluid thermal conductivity ratio α between 0.2 and 1000.0 and dimensionless wall thickness W between 0.25 and 1.375. Results indicate that the Nusselt number along the vertical wall-fluid interface is a complex function of both Ra and α. In general, the relative heat removal contribution by conduction in the wall through the top horizontal surface ηN decreases with Ra while that for the bottom surface ηs increases. For 0.2 ≤ α ≤ 5.0, ηs is nearly independent of Ra. Moreover, for Ra ≥ 105, 0.2 ≤ α ≤ 5.0 and 0.25 ≤ W ≤ 1.375, ηs is independent of α while ηN tends to zero with increasing α.

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