This paper deals with the steady, laminar, and two-dimensional natural convection inside vertical parallel-plate channels with isoflux heating. The main objective of this paper is to assess the joint influence of intense heating and variable physical properties on the flow and heat transfer characteristics of the upward air. To capture the physics of the problem, the discretized conservation equations are solved by the finite-volume technique in an aggrandized computational domain that is much larger than the physical domain. Representative numerical results based on the FLUENT computer program are presented in terms of local quantities such as air velocity and temperature profiles, as well as global quantities such as the average heat transfer coefficients and mass flow rates, all in response to the controlling geometrical and thermal parameters. A detailed comparison of these results is made against those produced by the simple model limited to constant physical properties.

1.
Manca
,
O.
,
Morrone
,
B.
,
Nardini
,
S.
, and
Naso
,
V.
, 2000,
Natural Convection in Open Channels, in Computational Analysis of Convection Heat Transfer
,
B.
Sunden
and
G.
Comini
, eds.,
WIT
,
Southampton, UK
, pp.
235
278
.
2.
Bar-Cohen
,
A.
,
Watwe
,
A. A.
, and
Prasher
,
R. S.
, 2003, “
Heat Transfer in Electronic Equipment
,”
Heat Transfer Handbook
,
A.
Bejan
and
A. D.
Kraus
, eds.,
Wiley
,
New York
, Chap. 13.
3.
Kays
,
W. M.
, and
Crawford
,
M. E.
, 1993,
Convective Heat and Mass Transfer
,
McGraw-Hill
,
New York
.
4.
Wirtz
,
R. A.
, and
Stutzman
,
R. J.
, 1982, “
Experiments on Free Convection Between Vertical Plates With Symmetric Heating
,”
ASME J. Heat Transfer
0022-1481,
104
, pp.
501
507
.
5.
Guo
,
Z. -Y.
,
Song
,
Y. -Z.
, and
Zhao
,
X. -W.
, 1991, “
Experimental Investigation on Natural Convection in Channel by Laser Speckle Photography
,”
Exp. Therm. Fluid Sci.
0894-1777,
4
, pp.
594
600
.
6.
Ambrosini
,
D.
,
Paoletti
,
D.
, and
Tanda
,
G.
, 2004, “
Investigation of Natural Convection in Vertical Channels by Schilieren and Holografic Interferometry
,”
J. Flow Visualization Image Process.
1065-3090,
11
(
4
) pp.
62
72
.
7.
Kettleborough
,
C. F.
, 1972, “
Transient Laminar Free Convection Between Heated Vertical Plates Including Entrance Effects
,”
Int. J. Heat Mass Transfer
0017-9310,
15
, pp.
883
896
.
8.
Nakamura
,
H.
,
Asako
,
Y.
, and
Naitou
,
T.
, 1982, “
Heat Transfer by Free Convection Between Two Parallel Flat Plates
,”
Numer. Heat Transfer
0149-5720,
5
, pp.
95
106
.
9.
Naylor
,
D.
,
Floryan
,
J. M.
, and
Tarasuk
,
J. D.
, 1991, “
A Numerical Study of Developing Free Convection Between Isothermal Vertical Plates
,”
ASME J. Heat Transfer
0022-1481,
113
, pp.
620
626
.
10.
Chang
,
T. -S.
, and
Lin
,
T. -F.
, 1989, “
Transient Buoyancy-Induced Flow Through a Heated, Vertical Channel of Finite Height
,”
Numer. Heat Transfer, Part A
1040-7782,
16
, pp.
15
35
.
11.
Morrone
,
B.
,
Campo
,
A.
, and
Manca
,
O.
, 1997, “
Optimum Plate Separation in Vertical Parallel-Plate Channels for Natural Convective Flows: Incorporation of Large Spaces at the Channel Extremes
,”
Int. J. Heat Mass Transfer
0017-9310,
40
, pp.
993
1000
.
12.
Anand
,
N. K.
,
Kim
,
S. H.
, and
Fletcher
,
L. S.
, 1992, “
The Effect of Plate Spacing of Vertical, Natural Convection Between Heated Parallel Plates
,”
ASME J. Heat Transfer
0022-1481,
114
, pp.
515
518
.
13.
Marcondes
,
F.
, and
Maliska
,
C. R.
, 1999, “
Treatment of the Inlet Boundary Conditions in Natural-Convection Flows in Open-Ended Channels
,”
Numer. Heat Transfer, Part B
1040-7790,
35
, pp.
317
345
.
14.
Gray
,
D. D.
, and
Giorgini
,
A.
, 1976, “
The Validity of the Boussinesq Approximation for Liquids and Gases
,”
Int. J. Heat Mass Transfer
0017-9310,
19
, pp.
545
551
.
15.
Hernández
,
J.
, and
Zamora
,
B.
, 2005, “
Effects of Variable Properties and Non-Uniform Heating on Natural Convection Flows in Vertical Channels
,”
Int. J. Heat Mass Transfer
0017-9310,
48
, pp.
793
807
.
16.
Vargaftik
,
N. B.
, 1975,
Tables of Thermophysical Properties of Liquids and Gases
, 2nd ed.,
Wiley
,
New York
.
17.
FLUENT 6.2 User’s Manual, Fluent Inc., 2006.
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