Abstract
It has been speculated that a forced pipe flow is always assisted by free convection owing to the dependency of fluid properties on its temperature. The purpose of the current study is to experimentally examine the effect of different-sized smooth horizontal pipes on mixed convection of water in internal flows under uniform heat flux (UHF) wall conditions. Infrared thermal imaging is used to measure outer surface temperature in axial and circumferential directions. Reynolds number range is taken between 1000 and 18,000 on three test sections of the diameter of 8 mm, 13.8 mm, and 17.8 mm. The outcome of varying tube diameter, mass flux, and heat flux on mixed flow characteristics is studied. The strength of free convection is illustrated by the ratio of top to bottom local heat transfer coefficient. It is found to be maximum at the tube outlet by 50% and 80% for 8 mm and 13.8 mm tube diameter than the inlet. This enhanced the laminar Nusselt number by 3 to 6 times the analytical value of Nu = 4.36 under UHF condition. The Nusselt number increases with the increase in the tube diameter. The Nusselt number increased by 36% when the surface area increased from a tube diameter of 8 mm to 17.8 mm. Also, the temperature distribution in the turbulent regime remains constant from the highest point to the bottom point. However, it significantly differs in laminar flow. A suitable correlation is suggested for the variation of the Nusselt number under the laminar regime showing the emphasis of free convection on forced convection.
Issue Section:
Electronic Cooling
References
1.
Shah
,
R. K.
, and
London
,
A. L.
, 1978
, Laminar Flow Forced Convection in Ducts: A Source Book for Compact Heat Exchanger Analytical Data
,
Academic Press
, Cambridge, MA
, Vol. Suppl. 1.2.
Boutina
,
L.
, and
Bessaïh
,
R.
, 2011
, “
Numerical Simulation of Mixed Convection Air-Cooling of Electronic Components Mounted in an Inclined Channel
,” Appl. Therm. Eng.
,
31
(11–12
), pp. 2052
–2062
.10.1016/j.applthermaleng.2011.03.021
3.
Li
,
Z. Y.
,
Huang
,
Z.
, and
Tao
,
W. Q.
, 2016
, “
Three-Dimensional Numerical Study on Fully-Developed Mixed Laminar Convection in Parabolic Trough Solar Receiver Tube
,” Energy
,
113
, pp. 1288
–1303
.10.1016/j.energy.2016.07.148
4.
Al-Farhany
,
K.
,
Alomari
,
M. A.
,
Albattat
,
A.
, and
Chamkha
,
A. J.
, 2022
, “
MHD Mixed Convection on Cu-Water Laminar Flow Through a Horizontal Channel Attached to Two Open Porous Enclosure
,” Eur. Phys. J. Spec. Top.
,
231
(13–14
), pp. 2851
–2864
.10.1140/epjs/s11734-022-00589-4
5.
Zayed
,
M. E.
,
Zhao
,
J.
,
Du
,
Y.
,
Kabeel
,
A. E.
, and
Shalaby
,
S. M.
, 2019
, “
Factors Affecting the Thermal Performance of the Flat Plate Solar Collector Using Nanofluids: A Review
,” Sol. Energy
,
182
, pp. 382
–396
.10.1016/j.solener.2019.02.054
6.
Everts
,
M.
,
Bhattacharyya
,
S.
,
Bashir
,
A. I.
, and
Meyer
,
J. P.
, 2020
, “
Heat Transfer Characteristics of Assisting and Opposing Laminar Flow Through a Vertical Circular Tube at Low Reynolds Numbers
,” Appl. Therm. Eng.
,
179
, p. 115696
.10.1016/j.applthermaleng.2020.115696
7.
Kupper
,
A.
,
Hauptmann
,
E. G.
, and
Iqbal
,
M.
, 1969
, “
Combined Free and Forced Convection in a Horizontal Tube Under Uniform Heat Flux
,” Sol. Energy
,
12
(4
), pp. 439
–446
.10.1016/0038-092X(69)90066-8
8.
Huang
,
Y. Y.
,
Zhang
,
L. J.
,
Yang
,
G.
, and
Wu
,
J. Y.
, 2018
, “
Secondary Flow and Entropy Generation of Laminar Mixed Convection in the Entrance Region of a Horizontal Square Duct
,” ASME J. Heat Mass Transfer-Trans. ASME
,
140
(3
), p. 034503.10.1115/1.4038134
9.
Alim
,
M. A.
,
Alam
,
M. M.
, and
Al-Mamun
,
A.
, 2007
, “
Joule Heating Effect on the Coupling of Conduction With Magnetohydrodynamic Free Convection Flow From a Vertical Flat Plate
,” Nonlinear Anal. Model. Control
,
12
(3
), pp. 307
–316
.10.15388/NA.2007.12.3.14688
10.
Babu
,
D. H.
, and
Narayana
,
P. V. S.
, 2016
, “
Joule Heating Effects on MHD Mixed Convection of a Jeffrey Fluid Over a Stretching Sheet With Power Law Heat Flux: A Numerical Study
,” J. Magn. Magn. Mater.
,
412
, pp. 185
–193
.10.1016/j.jmmm.2016.04.011
11.
Brown
,
A. R.
, and
Thomas
,
M. A.
, 1965
, “
Combined Free and Forced Convection Heat Transfer for Laminar Flow in Horizontal Tubes
,” J. Mech. Eng. Sci.
,
7
(4
), pp. 440
–448
.10.1243/JMES_JOUR_1965_007_066_02
12.
Bergles
,
A. E.
, and
Simonds
,
R. R.
, 1971
, “
Combined Forced and Free Convection for Laminar Flow in Horizontal Tubes With Uniform Heat Flux
,” Int. J. Heat Mass Transfer
,
14
(12
), pp. 1989
–2000
.10.1016/0017-9310(71)90023-8
13.
Morcos
,
S. M.
, and
Bergles
,
A. E.
, 1975
, “
Experimental Investigation of Combined Forced and Free Laminar Convection in Horizontal Tubes
,” ASME J. Heat Transfer-Trans. ASME
,
97
(2
), pp. 212
–219
.10.1115/1.3450343
14.
Ghajar
,
A. J.
, and
Tam
,
L. M.
, 1995
, “
Flow Regime Map for a Horizontal Pipe With Uniform Wall Heat Flux and Three Inlet Configurations
,” Exp. Therm. Fluid Sci.
,
10
(3
), pp. 287
–297
.10.1016/0894-1777(94)00107-J
15.
Yasuo
,
M.
,
Kozo
,
F.
,
Shinobu
,
T.
, and
Masakuni
,
N.
, 1966
, “
Forced Convective Heat Transfer in Uniformly Heated Horizontal Tubes 1st Report-Experimental Study on the Effect of Buoyancy
,” Int. J. Heat Mass Transfer
,
9
(5
), pp. 453
–463
.10.1016/0017-9310(66)90101-3
16.
Chen
,
X.
,
Wang
,
C.
,
Wu
,
Y.
,
Chen
,
C.
, and
Ma
,
C.
, 2016
, “
Numerical Simulation of Mixed Convection Heat Transfer of Molten Salt in Horizontal Square Tube With Single Surface Heating
,” Appl. Therm. Eng.
,
104
, pp. 282
–293
.10.1016/j.applthermaleng.2016.05.054
17.
Faheem
,
A.
,
Ranzi
,
G.
,
Fiorito
,
F.
, and
Lei
,
C.
, 2016
, “
A Numerical Study of Turbulent Mixed Convection in a Smooth Horizontal Pipe
,” ASME J. Heat Mass Transfer-Trans. ASME
,
138
(1
), p. 012501.10.1115/1.4031112
18.
Ede
,
A. J.
, 1961
, “
The Heat Transfer Coefficient for Flow in a Pipe
,” Int. J. Heat Mass Transfer
,
4
, pp. 105
–110
.10.1016/0017-9310(61)90065-5
19.
Zhang
,
S.
, 2022
, “
Mixed Convective Heat Transfer of Medium-Prandtl-Number Fluids in Horizontal Circular Tubes
,” Int. J. Heat Mass Transfer
,
190
, p. 122740
.10.1016/j.ijheatmasstransfer.2022.122740
20.
Andrzejczyk
,
R.
, and
Muszynski
,
T.
, 2017
, “
Thermodynamic and Geometrical Characteristics of Mixed Convection Heat Transfer in the Shell and Coil Tube Heat Exchanger With Baffles
,” Appl. Therm. Eng.
,
121
, pp. 115
–125
.10.1016/j.applthermaleng.2017.04.053
21.
Chae
,
M. S.
,
Lee
,
D. Y.
, and
Chung
.
B. J.
, 2019
, “
Experimental Study on Local Variation of Buoyancy-Aided Mixed Convection Heat Transfer in a Vertical Pipe Using a Mass Transfer Method
,” Exp. Therm. Fluid Sci.
,
104
, pp. 105
–115
.10.1016/j.expthermflusci.2019.02.015
22.
Ganjbakhsh
,
N.
,
Alikhani
,
S.
, and
Behzadmehr
,
A.
, 2019
, “
Numerical Study of the Effects of Surface Roughness on the Mixed Convection Heat Transfer of a Laminar Flow Inside a Horizontal Curved Dimpled Tube
,” Heat Mass Transfer
,
55
(7
), pp. 2009
–2016
.10.1007/s00231-018-2502-4
23.
Everts
,
M.
, and
Meyer
,
J. P.
, 2020
, “
Laminar Hydrodynamic and Thermal Entrance Lengths for Simultaneously Hydrodynamically and Thermally Developing Forced and Mixed Convective Flows in Horizontal Tubes
,” Exp. Therm. Fluid Sci.
,
118
, p. 110153
.10.1016/j.expthermflusci.2020.110153
24.
Everts
,
M.
,
Mahdavi
,
M.
,
Sharifpur
,
M.
, and
Meyer
,
J. P.
, 2023
, “
Simultaneous Development of the Hydrodynamic and Thermal Boundary Layers of Mixed Convective Laminar Flow Through a Horizontal Tube With a Constant Heat Flux
,” Int. J. Therm. Sci.
,
187
, p. 108178
.10.1016/j.ijthermalsci.2023.108178
25.
Churchill
,
S. W.
, and
Chu
,
H. H. S.
, 1975
, “
Correlating Equations for Laminar and Turbulent Free Convection From a Horizontal Cylinder
,” Int. J. Heat Mass Transfer
,
18
(9
), pp. 1049
–1053
.10.1016/0017-9310(75)90222-7
26.
Meyer
,
J. P.
, and
Everts
,
M.
, 2018
, “
Single-Phase Mixed Convection of Developing and Fully Developed Flow in Smooth Horizontal Circular Tubes in the Laminar and Transitional Flow Regimes
,” Int. J. Heat Mass Transf
er,
117
, pp. 1251
–1273
.10.1016/j.ijheatmasstransfer.2017.10.070
27.
Bergman
,
T. L.
,
Lavine
,
A. S.
,
Incropera
,
F. P.
, and
Dewitt
,
D. P.
, 2011
, Fundamentals of Heat and Mass Transfer, 2011. Fundamentals of Heat and Mass Transfer
, 7th ed.
28.
Lemmon
, E. W.
,
Huber
, M. L.
, and
McLinden
, M. O.
, 2002
, “NIST Reference Fluid Thermodynamic and Transport Properties (REFPROP)
,” NIST Standard Reference Database 23, v7, accessed May 26, 2023, https://webbook.nist.gov/chemistry/fluid/
29.
Petukhov
,
B. S.
, and
Polyakov
,
A. F.
, 1970
, “
Flow and Heat Transfer in Horizontal Tubes Under Combined Effect of Forced and Free Convection
,” Int. Heat Transfer Conf.
4
, pp. 1
–11
.10.1615/IHTC4.3690
30.
Heris
,
S. Z.
,
Etemad
,
S. G.
, and
Esfahany
,
M. N.
, 2006
, “
Experimental Investigation of Oxide Nanofluids Laminar Flow Convective Heat Transfer
,” Int. Commun. Heat Mass Transfer
,
33
(4
), pp. 529
–535
.10.1016/j.icheatmasstransfer.2006.01.005
31.
Siegwarth
,
D. P.
,
Mikesell
,
R. D.
,
Readal
,
T. C.
, and
Hanratty
,
T. J.
, 1969
, “
Effect of Secondary Flow on the Temperature Field and Primary Flow in a Heated Horizontal Tube
,” Int. J. Heat Mass Transfer
,
12
(12
), pp. 1535
–1552
.10.1016/0017-9310(69)90090-8
32.
Mahalingam
,
R.
,
Tilton
,
L. O.
, and
Coulson
,
J. M.
, 1975
, “
Heat Transfer in Laminar Flow of Non-Newtonian Fluids
,” Chem. Eng. Sci.
,
30
(8
), pp. 921
–929
.10.1016/0009-2509(75)80058-3
33.
Sieder
,
E. N.
, and
Tate
,
G. E.
, 1936
, “
Heat Transfer and Pressure Drop of Liquids in Tubes
,” Ind. Eng. Chem.
,
28
(12
), pp. 1429
–1435
.10.1021/ie50324a027
34.
Mori
,
Y.
, and
Futagami
,
K.
, 1967
, “
Forced Convective Heat Transfer in Uniformly Heated Horizontal Tubes (2nd Report, Theoretical Study)
,” Int. J. Heat Mass Transfer
,
10
(12
), pp. 1801
–1813
.10.1016/0017-9310(67)90051-8
35.
Meyer
,
J. P.
,
Bashir
,
A. I.
, and
Everts
,
M.
, 2019
, “
Single-Phase Mixed Convective Heat Transfer and Pressure Drop in the Laminar and Transitional Flow Regimes in Smooth Inclined Tubes Heated at a Constant Heat Flux
,” Exp. Therm. Fluid Sci.
,
109
, p. 109890
.10.1016/j.expthermflusci.2019.109890
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