The benefits and drawbacks of a multimegawatt downwind compared to upwind wind turbine are assessed using unsteady, three-dimensional (3D) computational fluid dynamics. For the same operating conditions, the downwind turbine has a 3% higher output power and a similar mean flapwise root bending moment. However, in comparison to the upwind turbine, the downwind turbine has a 3% higher thrust and a factor 3 larger peak-to-peak unsteady loading. These features arise due to higher flow incidences on the blade, higher axial velocities ahead of the rotor, and higher loading on the inboard span of the blade when the downwind turbine is compared to the upwind turbine. Overall, it is concluded that the downwind turbine configuration may be better suited for the design of multimegawatt offshore wind turbines.

Issue Section:
Research Papers
Keywords:
Efficiency, Renewable, Simulation, Wind, Wind turbine
Topics:
Blades, Rotation, Rotors, Thrust, Turbines, Flow (Dynamics), Wind turbines, Stress, Simulation

References

1.
Global Wind Energy Council
,
2013
, “
Global Wind Report Annual Market Update 2013
.”
2.
Paska
,
J.
,
Sałek
,
M.
, and
Surma
,
T.
,
2009
, “
Current Status and Perspectives of Renewable Energy Sources in Poland
,”
Renewable Sustainable Energy Rev.
,
13
(
1
), pp.
142
–
154
.10.1016/j.rser.2007.06.013
Google Scholar
Crossref
Search ADS
 
3.
Lee
,
A. T.
, and
Flay
,
R. G.
,
1999
, “
Compliant Blades for Passive Power Control of Wind Turbines
,”
Trans. Inst. Prof. Eng. N. Z., Electr./Mech./Chem. Eng. Sect.
,
26
(
1
), p.
7
.10.1260/0309524001495369
5.
Yoshida
,
S.
,
2006
, “
Performance of Downwind Turbines in Complex Terrain
,”
Wind Eng.
,
30
(
6
), pp.
487
–
501
.10.1260/030952406779994169
Google Scholar
Crossref
Search ADS
 
6.
Glasgow
,
J. C.
,
Miller
,
D. R.
, and
Corrigan
,
R. D.
,
1981
, “
Comparison of Upwind and Downwind Rotor Operations of the DOE/NASA 100-kW MOD-O Wind Turbine
,”
2nd DOE/NASA Wind Turbine Dynamics Workshop
, Cleveland, Feb. 24–26, Vol.
1
, pp.
24
–
26
.
7.
Manwell
,
J. F.
,
Rogers
,
A.
,
Ellis
,
A.
,
Abdulwahid
,
U.
, and
Solomon
,
M.
,
2001
, “
Experimental Investigation of Yaw Damping on a Downwind Turbine
,”
AIAA
Paper No. 2001-0042.10.2514/6.2001---42
8.
Picot
,
N.
,
Verelst
,
D. R. S.
, and
Larsen
,
T. J.
,
2011
, “
Free Yawing Stall-Controlled Downwind Wind Turbine With Swept Blades and Coned Rotor
,”
Proceedings of the European Wind Energy Association
.
9.
Kress
,
C.
,
Chokani
,
N.
, and
Abhari
,
R. S.
,
2015
, “
Downwind Wind Turbine Yaw Stability and Performance
,” (in press).
10.
Yoshida
,
K.
,
Xianwu
,
L.
,
Shuhong
,
L.
,
Eguchi
,
H.
, and
Nishi
,
M.
,
2011
, “
Development of Micro Downwind Turbine Generator Having Soft Blades
,”
J. Environ. Eng. (Trans. AIJ)
,
6
(
3
), pp.
313
–
321
.10.1299/jfst.6.313
11.
Hubbard
,
H. H.
, and
Shepard
,
K. P.
,
1991
, “
Aeroacoustics of Large Wind Turbines
,”
J. Acoust. Soc. Am.
,
86
(
6
), pp.
2495
–
2508
.10.1121/1.401021
Google Scholar
Crossref
Search ADS
 
12.
Möller
,
L.
, and
Olsson
,
G.
,
1987
, “
Operational Experiences From WTS-3 Wind Turbine Maglarp, Sweden
,”
IEE Proc., Part A
,
134
(
5
), pp.
431
–
434
.10.1049/ip---a---1.1987.0065
13.
Kress
,
C.
,
Chokani
,
N.
, and
Abhari
,
R. S.
,
2015
, “
Design Considerations of Rotor Cone Angle for Downwind Wind Turbines
,”
ASME
Paper No. GT2015-42335.
14.
Duque
,
E. P. N.
,
Van Dam
,
C.
, and
Hughes
,
S. C.
,
1999
, “
Navier–Stokes Simulations of the NREL Combined Experiment Phase II Rotor
,”
EWEC- Conference
, Nice, France, pp.
79
–
84
.10.2514/6.1999-37
15.
Duque
,
E. P. N.
,
Johnson
,
W.
,
van Dam
,
C. P.
,
Cortes
,
R.
, and
Yee
,
K.
,
2000
, “
Numerical Predictions of Wind Turbine Power and Aerodynamic Loads for the NREL Phase II Combined Experimental Rotor
,”
AIAA
Paper No. 2000-0038.
16.
Janajreh
,
I.
,
Talab
,
I.
, and
Macpherson
,
J.
,
2010
, “
Numerical Simulation of Tower Rotor Interaction for Downwind Wind Turbine
,”
Modell. Simul. Eng.
,
2010
, p.
860814
.10.1155/2010/860814
17.
Zahle
,
F.
,
Srensen
,
N. N.
, and
Johansen
,
J.
,
2009
, “
Wind Turbine Rotor-Tower Interaction Using an Incompressible Overset Grid Method
,”
Wind Energy
,
12
(
6
), pp.
594
–
619
.10.1002/we.327
Google Scholar
Crossref
Search ADS
 
18.
Ansys, Inc.
,
2013
,
ansys cfx-Solver Theory Guide
,
Ansys
,
Canonsburg
.
19.
Menter
,
F. R.
,
1993
, “
Zonal Two Equation k-Turbulence Models for Aerodynamic Flows
,”
AIAA
Paper No. 2906.10.2514/6.1993---2906
20.
Tsalicoglou
,
C.
,
Jafari
,
S.
,
Chokani
,
N.
, and
Abhari
,
R.
,
2014
, “
RANS Computations of MEXICO Rotor in Uniform and Yawed Inflow
,”
ASME J. Eng. Gas Turbines Power
,
136
(
1
), p.
011202
.10.1115/1.4025362
Google Scholar
Crossref
Search ADS
 
21.
Wang
,
J.
,
2014
, “
Unsteady Full RANS Simulation of Downwind Wind Turbine
,” Master's thesis, ETH Zurich, Zurich.
22.
Johansen
,
J.
, and
Sørensen
,
N.
,
2004
, “
Aerofoil Characteristics From 3D CFD Rotor Computations
,”
Wind Energy
,
7
(
4
), pp.
283
–
294
.10.1002/we.127
Google Scholar
Crossref
Search ADS
 
23.
Hansen
,
M. O. L.
,
Sørensen
,
N. N.
, and
Michelsen
,
J. A.
,
1997
, “
Extraction of Lift, Drag and Angle of Attack From Computed 3-D Viscous Flow Around a Rotating Blade
,”
European Wind Energy Conference
, Dublin.
Copyright © 2015 by ASME
You do not currently have access to this content.