The present work investigates the effects of buoyancy and wall heating condition on the thermal performance of a rotating two-pass square channel with smooth walls. The U-bend channel has a square cross section with a hydraulic diameter of 5.08 cm (2 in.). The lengths of the first and second passes are 514 mm and 460 mm, respectively. The turbulent flow entered the channel with Reynolds numbers of up to 34,000. The rotational speed varied from 0 to 600 rpm with rotational numbers up to 0.75. For this study, two approaches were considered for tracking the buoyancy effect on heat transfer. In the first case, the density ratio was set constant, and the rotational speed was varied. In the second case, the density ratio was changed in the stationary case, and the effect of density ratio was discussed. The range of buoyancy number along the channel is 0–6. The objective was to investigate the impact of buoyancy forces on a broader range of rotation number (0–0.75) and buoyancy number scales (0–6), and their combined effects on heat transfer coefficient for a channel with an aspect ratio of 1 : 1. Results showed that increasing the density ratio increased the heat transfer ratio in both stationary and rotational cases. Furthermore, in rotational cases, buoyancy force effects were very significant. Increasing the rotation number induced more buoyancy forces, which led to an enhancement in heat transfer. The buoyancy effect was more visible in the turning region than any other region.

References

References
1.
Deng
,
H.
,
Qui
,
L.
,
Tao
,
Z.
, and
Tian
,
S.
,
2013
, “
Heat Transfer Study in Rotating Smooth Square U-Duct at High Rotation Number
,”
Int. J. Heat Mass Transfer
,
66
, pp.
733
744
.
2.
Wagner
,
J. H.
,
Johnson
,
B. V.
, and
Hajek
,
T. J.
,
1989
, “
Heat Transfer in Rotating Passages With Smooth Walls and Radial Outward Flow
,”
34th Gas Turbine and Aeroengine Congress and Exhibition
,
Toronto, Ontario, Canada
, Paper No. 89-GT-272.
3.
Amano
,
R. S.
, and
Beyhaghi
,
S.
,
2016
, “
Heat Transfer in a Rotating Two-Pass Square Channel Representing Internal Cooling of Gas Turbine Blades
,”
54th AIAA Aerospace Sciences Meeting
,
San Diego, CA
, p.
0655
.
4.
Li
,
Y.
,
Deng
,
H.
,
Xu
,
G.
, and
Tian
,
S.
,
2015
, “
Heat Transfer Investigation in Rotating Smooth Square U-Duct With Different Wall-Temperature Ratios and Channel Orientations
,”
Int. J. Heat Mass Transfer
,
89
, pp.
10
23
.
5.
Burberi
,
E.
,
Missini
,
D.
,
Cocchi
,
L.
,
Mazzei
,
L.
,
Andreini
,
A.
, and
Facchini
,
B.
,
2016
, “
Effect of Rotation on a Gas Turbine Blade Internal Cooling System: Numerical Investigation
,”
ASME J. Turbomach.
139
(
3
), p.
031005
.
6.
Mayo
,
I.
,
Arts
,
T.
, and
Wyer
,
N.
,
2017
, “
Rotation Effects on the Heat Transfer Distribution in a Two-Pass Rotation Internal Cooling Channel Equipped With Triangular Ribs
,”
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition
,
Charlotte, NC
,
June 26–30
, Paper No. GT2017-64879, p. V05AT16A017.
7.
Grosnickel
,
T.
,
Duchaine
,
F.
,
Gicquel
,
L. Y. M.
, and
Koupper
,
C.
,
2017
, “
Large Eddy Simulations of Static and Rotating Ribbed Channels in Adiabatic and Isothermal Conditions
,”
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition
,
Charlotte, NC
,
June 26–30
, Paper No. GT2017-64241, p. V05AT11A012.
8.
Johnson
,
B. V.
,
Wagner
,
J. H.
, and
Yeh
,
F. C.
,
1992
, “
Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow
,”
ASME 1992 International Gas Turbine and Aeroengine Congress and Exposition
,
Cologne, Germany
,
June 1–4
, Paper No. 92-GT-191, p. V004T09A008.
9.
Bergman
,
T. L.
,
Lavine
,
A. S.
,
Incropera
,
F. P.
, and
Dewitt
,
D. P.
,
2011
,
Fundamentals of Heat and Mass Transfer
,
7th ed.
,
John Wiley & Sons. Inc.
,
New York
.
10.
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
.
11.
Colburn
,
A. P.
,
1964
, “
A Method of Correlating Forced Convection Heat Transfer Data and a Comparison With Fluid Friction
,”
Int. J. Heat Mass Transfer
,
7
(
12
), pp.
1359
1384
.
12.
Yang
,
Y.
, and
Fuchs
,
L.
,
1993
, “
Numerical Study of Viscous Flow in a Rotating Rectangular Channel
,”
Int. J. Eng. Sci.
,
31
(
6
), pp.
873
881
.
13.
Sewall
,
E. A.
, and
Tafti
,
D.
,
2005
, “
Large Eddy Simulation of Flow and Heat Transfer in the Developing Flow Region of a Rotating Gas Turbine Blade Internal Cooling Duct With Coriolis and Buoyancy Forces
,”
ASME J. Turbomach.
,
130
(
1
), p.
011005
.
14.
Li
,
Y.
,
Xu
,
G.
,
Deng
,
H.
, and
Tian
,
S.
,
2014
, “
Buoyancy Effect on Heat Transfer in Rotating Smooth Square U-Duct at High Rotation Number
,”
Propulsion Power Res.
,
3
(
3
), pp.
107
120
.
15.
Huh
,
M.
,
Lei
,
J.
, and
Han
,
J. C.
,
2011
, “
Influence of Channel Orientation on Heat Transfer in a Two-Pass Smooth and Ribbed Rectangular Channel (AR = 2:1) Under Large Rotation Numbers
,”
ASME J. Turbomach.
,
134
(
1
), p.
011022
.
16.
Huh
,
M.
,
Lei
,
J.
,
Hsien
,
Y.
, and
Han
,
J. C.
,
2009
, “
High Rotation Number Effects on Heat Transfer in a Rectangular (AR = 2:1) Two-Pass Channel
,”
ASME Turbo Expo 2009: Power for Land, Sea, and Air
,
Orlando, FL
,
June 8–12
, Paper No. GT2009-59421, pp.
383
394
.
17.
Smith
,
L.
,
Karim
,
H
,
Etemad
,
S.
,
Pfefferle
,
W.
, and
Cunha, F.J.
,
2006
,
Gas Turbine Handbook
,
U.S. Department of Energy-National Energy Technology Laboratory (NETL)
,
Morgantown, WV
, pp.
389
410
.
18.
Amano
,
R. S.
,
Beyhaghi
,
S.
,
Dong
,
P.
,
Saravani
,
S. M.
, and
Morrison
,
M.
,
2017
, “
Computational and Experimental Investigation of Heat Transfer in Stationary and Rotating Internal Ducts With High Rotation Numbers
,”
15th International Energy Conversion Engineering Conference
,
Atlanta, GA
.
19.
Kumar
,
S.
,
2012
,
Investigation of Heat Transfer and Flow Using Ribs Within Gas Turbine Blade Cooling Passage: Experimental and Hybrid LES/RANS Modeling
,
University of Wisconsin-Milwaukee
,
Milwaukee, WI
.
20.
Nicoud
,
F.
, and
Ducros
,
F.
,
1999
, “
Subgrid-Scale Stress Modelling Based on the Square of the Velocity Gradient Tensor
,”
Flow Turbul. Combust.
,
62
(
3
), pp.
183
200
.
21.
Bose
,
S. T.
, and
Moin
,
P.
,
2014
, “
A Dynamic Slip Boundary Condition for Wall-Modeled Large-Eddy Simulation
,”
Phys. Fluids
,
26
(
1
), pp.
015104
.
22.
Wheeler
,
A. J.
, and
Ganji
,
A. R.
,
2010
,
Introduction to Engineering Experimentation
,
3rd ed.
,
Prentice Hall
,
Englewood Cliffs, NJ
.
You do not currently have access to this content.