This paper presents a comparative numerical study of heat transfer enhancement in steady, laminar, hydrodynamically fully developed flow of water-based ferrofluids under no magnetic field in micro and macro parallel plate channels subjected to constant equal heat fluxes on its top and bottom, considering Brownian diffusion and thermophoresis of ferroparticles in the base fluid. While the microchannel results match very well with the experimental data for water in an equivalent microtube (Kurtoglu et al., 2014, “Experimental Study on Convective Heat Transfer Performance of Iron Oxide Based Ferrofluids in Microtubes,” ASME J. Therm. Sci. Eng. Appl., 6(3), p. 034501.), the numerically predicted enhancement factor in ferrofluids is much below that for the same microtube. A detailed parametric study points to possible inaccuracies in the experimental results of Kurtoglu et al. (2014, “Experimental Study on Convective Heat Transfer Performance of Iron Oxide Based Ferrofluids in Microtubes,” ASME J. Therm. Sci. Eng. Appl., 6(3), p. 034501.) for ferrofluids. The nanoparticle concentration profiles in the microchannel flow reveal that (a) the nanoparticle concentration at the wall increases with axial distance, (b) the wall nanoparticle concentration decreases with increasing heat flux, and (c) the concentration profile of nanoparticles is parabolic at the exit. A comparison of thermally developing flow in microchannel and macrochannel of the same length (0.025 m) indicates that the enhancement factor at the microchannel exit is 1.089 which is only marginally higher than that at the macrochannel exit in the heat flux range of 20–80 kW/m2. On the other hand, for the thermally fully developed flow in both microchannel and macrochannel of the same length (0.54 m) the maximum enhancement factor for the macrochannel is 1.7, as compared to 1.1 for the microchannel, in the heat flux range of 1–4 kW/m2.

References

References
1.
Goharkhah
,
M.
, and
Ashjaee
,
M.
,
2014
, “
Effect of an Alternating Nonuniform Magnetic Field on Ferrofluid Flow and Heat Transfer in a Channel
,”
J. Magn. Magn. Mater.
,
362
, pp.
80
89
.
2.
Azizian
,
R.
,
Doroodchi
,
E.
,
McKrell
,
T.
,
Buongiorno
,
J.
,
Hu
,
L. W.
, and
Moghtaderi
,
B.
,
2014
, “
Effect of Magnetic Field on Laminar Convective Heat Transfer of Magnetite Nanofluids
,”
Int. J. Heat Mass Transfer
,
68
, pp.
94
109
.
3.
Choi
,
S.
,
1995
, “
Enhancing Thermal Conductivity of Fluids With Nanoparticles
,”
Developments and Applications of Non-Newtonian Flows
,
D. A.
Siginer
and
H. P.
Wang
, eds.,
ASME
,
New York
, pp.
99
105
.
4.
Eastman
,
J. A.
,
Choi
,
S. U. S.
,
Li
,
S.
,
Thompson
,
L. J.
, and
Lee
,
S.
,
1996
, “
Enhancing Thermal Conductivity Through the Development of Nanofluids
,”
Proc. Mat. Res. Soc., Symp.
,
457
, pp.
3
11
.
5.
Xuan
,
Y.
, and
Li
,
Q.
,
2000
, “
Heat Transfer Enhancement of Nanofluids
,”
Int. J. Heat Fluid Flow
,
21
(
1
), pp.
58
64
.
6.
Eastman
,
J. A.
,
Choi
,
S. U. S.
,
Li
,
S.
,
Yu
,
W.
, and
Thompson
,
L. J.
,
2001
, “
Anomalously Increased Effective Thermal Conductivities of Ethylene Glycol-Based Nanofluids Containing Copper Nanoparticles
,”
Appl. Phys. Lett.
,
78
(
6
), pp.
718
720
.
7.
Wen
,
D.
, and
Ding
,
Y.
,
2004
, “
Effect on Heat Transfer of Particle Migration in Suspensions of Nanoparticles Flowing Through Minichannels
,”
ASME
Paper No. ICMM2004-2434.
8.
Nan
,
C. W.
,
Birringer
,
R.
,
Clarke
,
D. R.
, and
Gleiter
,
H.
,
1997
, “
Effective Thermal Conductivity of Particulate Composites With Interfacial Thermal Resistance
,”
J. Appl. Phys.
,
81
(
10
), pp.
6692
6699
.
9.
Keblinski
,
P.
,
Phillpot
,
S. R.
,
Choi
,
S. U. S.
, and
Eastman
,
J. A.
,
2002
, “
Mechanisms of Heat Flow in Suspensions of Nano-Sized Particles (Nanofluids)
,”
Int. J. Heat Mass Transfer
,
45
(
4
), pp.
855
863
.
10.
Jang
,
S. P.
, and
Choi
,
S. U. S.
,
2004
, “
Role of Brownian Motion in the Enhanced Thermal Conductivity of Nanofluids
,”
Appl. Phys. Lett.
,
84
(
21
), pp.
4316
4318
.
11.
Koo
,
J.
, and
Kleinstreuer
,
C.
,
2004
, “
A New Thermal Conductivity Model for Nanofluids
,”
J. Nanopart. Res.
,
6
(
6
), pp.
577
588
.
12.
Prasher
,
R.
,
Bhattacharya
,
P.
, and
Phelan
,
P. E.
,
2005
, “
Brownian Motion-Based Convective-Conductive Model for the Effective Thermal Conductivity of Nanofluids
,”
ASME J. Heat Transfer
,
128
(
6
), pp.
588
595
.
13.
Xuan
,
Y.
, and
Roetzel
,
W.
,
2000
, “
Conceptions of Heat Transfer Correlation of Nanofluids
,”
Int. J. Heat Mass Transfer
,
43
(
19
), pp.
3701
3707
.
14.
Buongiorno
,
J.
,
2006
, “
Convective Transport in Nanofluids
,”
ASME J. Heat Transfer
,
128
(
3
), pp.
240
250
.
15.
Rossi di Schio
,
E.
,
Celli
,
M.
, and
Barletta
,
A.
,
2013
, “
Effects of Brownian Diffusion and Thermophoresis on the Laminar Forced Convection of a Nanofluid in a Channel
,”
ASME J. Heat Transfer
,
136
(
2
), p.
022401
.
16.
Burmeister
,
L. C.
,
1993
,
Convective Heat Transfer
,
2nd ed.
,
Wiley
,
New York
.
17.
Kurtoglu
,
E.
,
Kaya
,
A.
,
Gozuacik
,
D.
,
Funda Yagci Acar
,
H.
, and
Kosar
,
A.
,
2014
, “
Experimental Study on Convective Heat Transfer Performance of Iron Oxide Based Ferrofluids in Microtubes
,”
ASME J. Therm. Sci. Eng. Appl.
,
6
(3), p.
034501
.
18.
Ghoshdastidar
,
P. S.
,
2012
,
Heat Transfer
,
2nd ed.
,
Oxford University Press
,
New Delhi, India
.
19.
Srivastava
,
N.
,
2011
, “A Numerical Investigation of Convective Heat Transfer in Macro and Microtube Flow,” M.Tech thesis, Indian Institute of Technology Kanpur, Kanpur, India.
20.
Brinkman
,
H. C.
,
1952
, “
The Viscosity of Concentrated Suspensions and Solutions
,”
J. Chem. Phys.
,
20
(4), pp.
571
581
.
21.
Maxwell
,
J. C.
,
1881
,
A Treatise on Electricity and Magnetism
,
2nd ed.
,
Clarendon
,
Oxford, UK
.
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