Laser interferometry and flow visualization were used to study free convective heat transfer inside a vertical channel. Most studies in the literature have investigated buoyancy forces in a single direction. The study presented here investigated opposing buoyancy forces, where one wall is warmer than the ambient and the other wall is cooler than the ambient. An experimental model of an isothermally, asymmetrically heated vertical channel was constructed. Interferometry provided temperature field visualization and flow visualization was used to obtain the streamlines. Experiments were carried out over a range of aspect ratios between 8.8 and 26.4, using temperature ratios of 0, −0.5, and −0.75. These conditions provide a modified Rayleigh number range of approximately 5 to 1100. In addition, the measured local and average Nusselt number data were compared to numerical solutions obtained using ANSYS FLUENT. Air was the fluid of interest. So the Prandtl number was fixed at 0.71. Numerical solutions were obtained for modified Rayleigh numbers ranging from the laminar fully developed flow regime to the turbulent isolated boundary layer regime. A semi-empirical correlation of the average Nusselt number was developed based on the experimental data.

Issue Section:
Natural and Mixed Convection
Keywords:
interferometry, flow visualization, numerical modeling, natural convection, vertical channel
Topics:
Buoyancy, Flow (Dynamics), Flow visualization, Interferometry, Natural convection, Rayleigh number, Temperature, Lasers, Computer simulation, Turbulence

References

1.
Aung
,
W.
,
1972
, “
Fully Developed Laminar Free Convection Between Vertical Plates Heated Asymmetrically
,”
Int. J. Heat Mass Transfer
,
15
(
8
), pp.
1577
–
1580
.10.1016/0017-9310(72)90012-9
2.
Elenbaas
,
W.
,
1942
, “
Heat Dissipation of Parallel Plates by Free Convection
,”
Physica
,
9
, pp.
1
–
28
.10.1016/S0031-8914(42)90053-3
3.
Aung
,
W.
,
Fletcher
,
L. S.
, and
Sernas
,
V.
,
1972
, “
Developing Laminar Free Convection Between Vertical Flat Plates With Asymmetric Heating
,”
Int. J. Heat Mass Transfer
,
15
(
11
), pp.
2293
–
2308
.10.1016/0017-9310(72)90048-8
4.
Bar-Cohen
,
A.
, and
Rohsenow
,
W. M.
,
1984
, “
Thermally Optimum Spacing of Vertical, Natural Convection Cooled, Parallel Plates
,”
ASME J. Heat Transfer
,
106
(
1
), pp.
116
–
123
.10.1115/1.3246622
5.
Raithby
,
G. D.
, and
Hollands
,
K. G. T.
,
1998
, “
Natural Convection
,”
Handbook of Heat Transfer
,
Rohsenow
,
W. M.
,
Harnett
,
J. P.
, and
Cho
,
Y. I.
, eds.,
McGraw-Hill
,
New York
, pp.
4.32
–
4.35
.
6.
Bodoia
,
J. R.
, and
Osterle
,
J. F.
,
1963
, “
The Development of Free Convection Between Heated Vertical Plates
,”
ASME J. Heat Transfer
,
84
(
1
), pp.
40
–
44
.10.1115/1.3684288
7.
Burch
,
T.
,
Rhodes
,
T.
, and
Acharya
,
S.
,
1985
, “
Laminar Natural Convection Between Finitely Conducting Vertical Plates
,”
Int. J. Heat Mass Transfer
,
28
(
6
), pp.
1173
–
1186
.10.1016/0017-9310(85)90125-5
8.
Naylor
,
D.
,
Floryan
,
J. M.
, and
Tarasuk
,
J. D.
,
1991
, “
Numerical Study of Developing Free Convection Between Isothermal Vertical Plates
,”
ASME J. Heat Transfer
,
113
(
3
), pp.
620
–
626
.10.1115/1.2910610
9.
Kazeminejad
,
H.
,
2005
, “
Laminar Free Convection in a Vertical Channel With Asymmetrical Heating
,”
Proceedings of the ASME Summer Heat Transfer Conference
, San Francisco, CA, Vol.
3
, pp.
521
–
530
.
10.
Roeleveld
,
D.
,
Naylor
,
D.
, and
Oosthuizen
,
P. H.
,
2009
, “
Empirical Correlations for Free Convection in an Isothermal Asymmetrically Heated Vertical Channel
,”
Heat Transfer Eng.
,
30
(
3
), pp.
189
−
196
.10.1080/01457630802304287
11.
Habib
,
H. A.
,
Said
,
S. A. M.
,
Ahmed
,
S. A.
, and
Asghar
,
A.
,
2002
, “
Velocity Characteristics of Turbulent Natural Convection in Symmetrically and Asymmetrically Heated Vertical Channels
,”
Exp. Therm. Fluid Sci.
,
26
(
1
), pp.
77
–
87
.10.1016/S0894-1777(02)00113-9
12.
Ayinde
,
T. F.
,
Said
,
S. A. M.
, and
Habib
,
M. A.
,
2008
, “
Turbulent Natural Convection Flow in a Vertical Channel With Anti-Symmetric Heating
,”
Heat Mass Transfer
,
44
(
10
), pp.
1207
–
1216
.10.1007/s00231-007-0359-z
13.
Roeleveld
,
D.
,
Naylor
,
D.
, and
Leong
,
W. H.
,
2014
, “
Free Convection in Antisymmetrically Heated Vertical Channels
,”
J. Heat Transfer
,
136
(
1
), p.
012502
.
14.
ANSYS, Inc.
,
2010
,
ANSYS FLUENT (Version 13.0)
.
15.
Goldstein
,
R. J.
,
1976
, “
Optical Temperature Measurement
,”
Measurement Techniques in Heat Transfer
,
E. R. G.
Eckert
and
R. J.
Goldstein
, eds.,
Technivision Services
,
Slough, UK
, pp.
177
–
228
.
16.
Poulad
,
M. E.
,
Naylor
,
D.
, and
Oosthuizen
,
P. H.
,
2011
, “
Measurement of Time-Averaged Turbulent Free Convection in a Tall Enclosure Using Interferometry
,”
ASME J. Heat Transfer
,
133
(
4
), p.
042501
.10.1115/1.4003081
17.
The Mathworks, Inc.
,
2010
,
MATLAB (Version R2010a), Natick, MA
.
18.
Slepicka
,
S. S.
, and
Cha
,
S. S.
,
1995
, “
Stabilized Nonlinear Regression for Interferogram Analysis
,”
Appl. Opt.
,
34
(
23
), pp.
5039
–
5044
.10.1364/AO.34.005039
19.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng.
,
75
(
1
), pp.
3
–
8
.
20.
Touloukian
,
Y. S.
,
Liley
,
P. E.
, and
Saxena
,
S. C.
,
1970
, “
Thermal Conductivity: Nonmetallic Liquids and Gases
,”
Thermophysical Properties of Matter
, Vol.
3
,
Plenum Publishing Corporation
,
New York
.
21.
Touloukian
,
Y. S.
, and
Makita
,
T.
,
1970
, “
Specific Heat: Nonmetallic Liquids and Gases
,”
Thermophysical Properties of Matter
, Vol.
6
,
Plenum Publishing Corporation
,
New York
.
22.
Touloukian
,
Y. S.
,
Saxena
,
S. C.
, and
Hestermans
,
P.
,
1975
, “
Viscosity: Nonmetallic Liquids and Gases
,”
Thermophysical Properties of Matter
, Vol.
11
,
Plenum Publishing Corporation
,
New York
.
23.
Roeleveld
,
D.
,
2013
, “
Experimental and Numerical Study of Free Convection in a Vertical Channel With Opposing Buoyancy Forces
,” Ph.D. thesis, Ryerson University, Toronto, Ontario.
24.
Walsh
,
P. C.
, and
Leong
,
W. H.
,
2004
, “
Effectiveness of Several Turbulence Models in Natural Convection
,”
Int. J. Numer. Methods Heat Fluid Flow
,
14
(
5
), pp.
633
−
648
.10.1108/09615530410539955
25.
Versteeg
,
H. K.
, and
Malalasekera
,
W.
,
1995
,
An Introduction to Computational Fluid Dynamics: The Finite Volume Method
,
Longman Group Ltd.
,
Essex
, UK.
26.
Patankar
,
S. V.
,
1980
,
Numerical Heat Transfer and Fluid Flow
,
Hemisphere Publishing Corporation
,
New York
.
27.
Van Doormaal
,
J. P.
, and
Raithby
,
G. D.
,
1984
, “
Enhancements of the SIMPLE Method for Predicting Incompressible Fluid Flows
,”
Numer. Heat Transfer
,
7
(
2
), pp.
147
–
163
.10.1080/01495728408961817
28.
Celik
,
I. B.
,
Ghia
,
U.
,
Roache
,
P. J.
,
Freitas
,
C. J.
,
Coleman
,
H.
, and
Raad
,
P. E.
,
2008
, “
Procedure for Estimation and Reporting of Uncertainty Due to Discretization in CFD Applications
,”
ASME J. Fluids Eng.
130
(
7
), p.
078001
. 10.1115/1.2960953
29.
Sparrow
,
E. M.
,
Chrysler
,
G. M.
, and
Azevedo
,
L. F.
,
1984
, “
Observed Flow Reversals and Measured-Predicted Nusselt Numbers for Natural Convection in an One-Sided Heated Vertical Channel
,”
ASME J. Heat Transfer
,
106
(
2
), pp.
325
−
332
.10.1115/1.3246676
30.
Churchill
,
S. W.
, and
Usagi
,
R.
,
1972
, “
A General Expression for the Correlation of Rates of Transfer and Other Phenomena
,”
AIChE J.
,
18
(
6
), pp.
1121
–
1128
.10.1002/aic.690180606
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