Computational fluid dynamics (CFD) and heat transfer simulations are conducted for a novel heat exchanger. The heat exchanger consists of semi-circle cross-sectioned tubes that create narrow slots oriented in the streamwise direction. Numerical simulations are conducted for Reynolds numbers (Re) ranging from 700 to 30,000. Three-dimensional turbulent flows and heat transfer characteristics in the tube bank region are modeled by the k-ε Reynolds-averaged Navier–Stokes (RANS) method. The flow structure predicted by the two-dimensional and three-dimensional simulations is compared against that observed by the particle image velocimetry (PIV) for Re of 1500 and 4000. The adequate agreement between the predicted and observed flow characteristics validates the numerical method and the turbulent model employed here. The three-dimensional and the two-dimensional steady flow simulations are compared to determine the effects of the wall on the flow structure. The wall influences the spatial structure of the vortices formed in the wake of the tubes and near the exit of the slots. The heat transfer coefficient of the slotted tubes improved by more than 40% compare to the traditional nonslotted tubes.

References

1.
Choi
,
S. U.
, and
Eastman
,
J. A.
,
1995
, “
Enhancing Thermal Conductivity of Fluids With Nanoparticles
,” Argonne National Laboratory, Report No. ANL/MSD/CP–84938; CONF-951135–29.
2.
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
.10.1063/1.1341218
3.
Timofeeva
,
E. V.
,
Routbort
,
J. L.
, and
Singh
,
D.
,
2009
, “
Particle Shape Effects on Thermophysical Properties of Alumina Nanofluids
,”
J. Appl. Phys.
,
106
(
1
), p.
014304
.10.1063/1.3155999
4.
Yang
,
Y.
,
Oztekin
,
A.
,
Neti
,
S.
, and
Mohapatra
,
S.
,
2012
, “
Particle Agglomeration and Properties of Nanofluids
,”
J. Nanopart. Res.
,
14
(
5
), p.
852
.10.1007/s11051-012-0852-2
5.
Jang
,
J. Y.
, and
Chen
,
L. K.
,
1997
, “
Numerical Analysis of Heat Transfer and Fluid Flow in a Three-Dimensional Wavy-Fin and Tube Heat Exchanger
,”
Int. J. Heat Mass Transfer
,
40
(
16
), pp.
3981
3990
.10.1016/S0017-9310(97)00047-1
6.
Nuntaphan
,
A.
,
Kiatsiriroat
,
T.
, and
Wang
,
C. C.
,
2005
, “
Air Side Performance at Low Reynolds Number of Cross-Flow Heat Exchanger Using Crimped Spiral Fins
,”
Int. Commun. Heat Mass Transfer
,
32
(
1–2
), pp.
151
165
.10.1016/j.icheatmasstransfer.2004.03.022
7.
Khan
,
W. A.
,
Culham
,
J. R.
, and
Yovanovich
,
M. M.
,
2006
, “
Convection Heat Transfer From Tube Banks in Crossflow: Analytical Approach
,”
Int. J. Heat Mass Transfer,
49
(
25–26
), pp.
4831
4838
.10.1016/j.ijheatmasstransfer.2006.05.042
8.
Khan
,
W. A.
,
Culham
,
R. J.
, and
Yovanovich
,
M. M.
,
2007
, “
Optimal Design of Tube Banks in Cross Flow Using Entropy Generation Minimization Method
,”
J. Thermophys. Heat Transfer
,
21
(
2
), pp.
372
378
.10.2514/1.26824
9.
Ravagnani
,
M. A. S. S.
,
Silva
,
A. P.
,
Biscaia
,
E. C.
, and
Caballero
,
J. A.
,
2009
, “
Optimal Design of Shell-and-Tube Heat Exchangers Using Particle Swarm Optimization
,”
Industrial & Engineering Chemistry Research
,
48
(
6
), pp.
2927
2935
.10.1021/ie800728n
10.
Matos
,
R. S.
,
Vargas
,
J.
,
Laursen
,
T. A.
, and
Saboya
,
F.
,
2001
, “
Optimization Study and Heat Transfer Comparison of Staggered Circular and Elliptic Tubes in Forced Convection
,”
Int. J. Heat Mass Transfer
,
44
(
20
), pp.
3953
3961
.10.1016/S0017-9310(01)00006-0
11.
Unuvar
,
A.
, and
Kargici
,
S.
,
2004
, “
An Approach for the Optimum Design of Heat Exchangers
,”
Int. J. Energy Res.
,
28
(
15
), pp.
1379
1392
.10.1002/er.1080
12.
Hilbert
,
R.
,
Janiga
,
G.
,
Baron
,
R.
, and
Thévenin
,
D.
,
2006
, “
Multi-Objective Shape Optimization of a Heat Exchanger Using Parallel Genetic Algorithms
,”
Int. J. Heat Mass Transfer
,
49
(
15–16
), pp.
2567
2577
.10.1016/j.ijheatmasstransfer.2005.12.015
13.
Stanescu
,
G.
,
Fowler
,
A. J.
, and
Bejan
,
A.
,
1996
, “
The Optimal Spacing of Cylinders in Free-Stream Cross-Flow Forced Convection
,”
Int. J. Heat Mass Transfer
,
39
(
2
), pp.
311
317
.10.1016/0017-9310(95)00122-P
14.
Leu
,
J.-S.
,
Wu
,
Y.-H.
, and
Jang
,
J.-Y.
,
2004
, “
Heat Transfer and Fluid Flow Analysis in Plate-Fin and Tube Heat Exchangers With a Pair of Block Shape Vortex Generators
,”
Int. J. Heat Mass Transfer
,
47
(
19–20
), pp.
4327
4338
.10.1016/j.ijheatmasstransfer.2004.04.031
15.
Torii
,
K.
,
Kwak
,
K. M.
, and
Nishino
,
K.
,
2002
, “
Heat Transfer Enhancement Accompanying Pressure-Loss Reduction With Winglet-Type Vortex Generators for Fin-Tube Heat Exchangers
,”
Int. J. Heat Mass Transfer
,
45
(
18
), pp.
3795
3801
.10.1016/S0017-9310(02)00080-7
16.
Hwang
,
S. W.
,
Kim
,
D. H.
,
Min
,
J. K.
, and
Jeong
,
J. H.
,
2012
, “
CFD Analysis of Fin Tube Heat Exchanger With a Pair of Delta Winglet Vortex Generators
,”
J. Mech. Sci. Technol.
,
26
(
9
), pp.
2949
2958
.10.1007/s12206-012-0702-2
17.
Popiel
,
C. O.
,
Robinson
,
D. I.
, and
Turner
,
J. T.
,
1993
, “
Vortex Shedding From a Circular Cylinder With a Slit and Concave Rear Surface
,”
Appl. Scientific Res.
,
51
(
1
), pp.
209
215
.10.1007/BF01082539
18.
Yayla
,
S.
,
2013
, “
Flow Characteristic of Staggered Multiple Slotted-Tubes in the Passage of a Fin Tube Heat Exchanger
,”
Strojniski vestnik–J. Mech. Eng.
,
59
(
7–8
), pp.
462
472
.10.5545/sv-jme.2012.902
19.
Reynolds
,
O.
,
1895
, “
On the Dynamical Theory of Incompressible Viscous Fluids and the Determination of the Criterion
,”
Philos. Trans. R. Soc. London, Ser. A
,
186
, pp.
123
164
.10.1098/rsta.1895.0004
20.
Shih
,
T. H.
,
Liou
,
W. W.
,
Shabbir
,
A.
,
Yang
,
Z.
, and
Zhu
,
J.
,
1995
, “
A New k-ϵ Eddy Viscosity Model for High Reynolds Number Turbulent Flows
,”
Comput. Fluids
,
24
(
3
), pp.
227
238
.10.1016/0045-7930(94)00032-T
21.
Taylor
,
G. I.
,
1938
, “
Production and Dissipation of Vorticity in a Turbulent Fluid
,”
Proc. Royal Soc. London. A, Math. Phys. Sci.
,
164
(
916
), pp.
15
23
.10.1098/rspa.1938.0002
22.
Grimison
,
E. D.
,
1937
, “
Correlation and Utilization of New Data on Flow Resistance and Heat Transfer for Cross Flow of Gases Over Tube Banks
,”
Trans. ASME
,
59
(
7
), pp.
583
594
.
23.
Žukauskas
,
A.
,
1972
, “
Heat Transfer From Tubes in Crossflow
,”
Adv. Heat Transfer
,
8
, pp.
93
160
.10.1016/S0065-2717(08)70038-8
24.
Žukauskas
,
A.
, and
Ulinskas
,
R.
,
1988
,
Heat Transfer in Tube Banks in Crossflow
,
Hemisphere
,
New York
.
25.
Incropera
,
F. P.
, and
DeWitt
,
D. P.
,
2011
,
Fundamentals of Heat and Mass Transfer
, 7th ed.,
Wiley
, Hoboken, NJ.
26.
ANSYS
Fluent 14.0 User’s Guide, Nov.
2011
.
27.
Webb
,
R. L.
, and
Eckert
,
E. R. G.
,
1972
, “
Application of Rough Surfaces to Heat Exchanger Design
,”
Int. J. Heat Mass Transfer
,
15
(
9
), pp.
1647
1658
.10.1016/0017-9310(72)90095-6
28.
Moon
,
S. W.
, and
Lau
,
S. C.
,
2003
, “
Heat Transfer Between Blockages With Holes in a Rectangular Channel
,”
ASME J. Heat Transfer
,
125
(
4
), pp.
587
594
.10.1115/1.1576812
You do not currently have access to this content.