In this paper, the first-ever measurements of the wake of a full-scale wind turbine using an instrumented uninhabited aerial vehicle (UAV) are reported. The key enabler for this novel measurement approach is the integration of fast response aerodynamic probe technology with miniaturized hardware and software for UAVs that enable autonomous UAV operation. The measurements, made to support the development of advanced wind simulation tools, are made in the near-wake (0.5D–3D, where D is rotor diameter) region of a 2 MW wind turbine that is located in a topography of complex terrain and varied vegetation. Downwind of the wind turbine, profiles of the wind speed show that there is strong three-dimensional shear in the near-wake flow. Along the centerline of the wake, the deficit in wind speed is a consequence of wakes from the rotor, nacelle, and tower. By comparison with the profiles away from the centerline, the shadowing effects of nacelle and tower diminish downstream of 2.5D. Away from the centerline, the deficit in wind speed is approximately constant ≈ 25%. However, along the centerline, the deficit is ≈ 65% near to the rotor, 0.5D–1.75D, and only decreases to ≈ 25% downstream of 2.5D.

References

1.
Zambrano
,
T. G.
, and
Gyatt
,
G. W.
, 1983, “
Wake Structure Measurements at the MOD-2 Cluster Test Facility at Goodnoe Hills
,”
IEEE Proceedings
,
Washington
, Vol.
130
, pp.
562
565
.
2.
Taylor
,
G. J.
, 1983, “
Wake and Performance Measurements on the Lawson-Tancred 17 m Horizontal-Axis Windmill
,”
IEEE Proceedings
, Vol.
130
, pp.
604
612
.
3.
Baker
,
R. W.
,
Walker
,
S. N.
, 1984, “
Wake Measurements Behind a Large Horizontal Axis Wind Turbine Generator
,”
Sol. Energy
,
33
, pp.
5
12
.
4.
Högström
,
U.
,
Asimakopoulos
,
D. N.
,
Kambezidis
,
H.
,
Helmis
,
C. G.
, and
Smedman
,
A.
, 1988, “
A Field Study of the Wake Behind a 2 MW Wind Turbine
,”
Atmos. Environ.
,
22
, pp.
803
820
.
5.
Kambezidis
,
H. D.
,
Asimakopoulos
,
D. N.
, and
Helmis
,
C. G.
, 1990, “
Wake Measurements Behind a Horizontal-Axis 50 kW Wind Turbine
,”
Solar Wind Technol.
,
7
, pp.
177
184
.
6.
Elliott
,
D. L.
, and
Barnard
,
J. C.
, 1990, “
Observations of Wind Turbine Wakes and Surface Roughness Effects on Wind Flow Variability
,”
Sol. Energy
,
45
, pp.
265
283
.
7.
Helmis
,
C. G.
,
Papadopoulos
,
K. H.
,
Asimakopoulos
,
D. N.
,
Papageorgas
,
P. G.
, and
Soilemes
,
A. T.
, 1995, “
An Experimental Study of the Near-Wake Structure of a Wind Turbine Operating over Complex Terrain
,”
Sol. Energy
,
54
, pp.
413
428
.
8.
Smith
,
D. A.
,
Harris
,
M. A.
,
Coffey
,
S.
,
Mikkelsen
,
T.
,
Jorgensen
,
H. E.
,
Mann
,
J.
, and
Danielian
,
G.
, 2006, “
Wind LIDAR Evaluation at the Danish Wind Test Site in Hovsore
,”
Wind Energy
,
9
, pp.
87
93
.
9.
Antoniou
,
I.
,
Courtney
,
M.
,
Jørgensen
,
H. E
,
Mikkelsen
,
T.
,
von Hunerbein
,
S.
,
Bradley
,
S.
,
Piper
,
B.
,
Harris
,
M.
,
Marti
,
I.
,
Aristu
,
M.
,
Foussekis
,
D.
, and
Nielsen
,
M. P.
, 2007, “
Remote Sensing the Wind Using LIDARs and SODARs
,”
Proceedings EWEC
.
10.
Courtney
,
M.
,
Wagner
,
R.
,
Lindelow
,
P.
, 2008, “
Testing and Comparison of LIDARs for Profile and Turbulence Measurements in Wind Energy
,”
14th International Symposium for the Advancement of Boundary Layer Remote Sensing, IOP Conference Series: Earth Environmental Science, (1012021)
.
11.
Axford
,
D. N.
, 1968, “
On the Accuracy of Wind Measurements using an Inertial Platform in an Aircraft and an Example of a Measurement of the Vertical Mesoscale of the Atmosphere
,”
J. Appl. Meteorl.
,
7
, pp.
645
666
.
12.
Lenschow
,
D. H.
, 1986,
“Aircraft Measurements in the Boundary Layer,”
Probing the Atmospheric Boundary Layer
,
D. H.
Lenschow
, ed.,
American Meteorological Society
, pp.
39
55
.
13.
Beswick
,
K. M.
,
Gallagher
,
M. W.
,
Webb
,
A. R.
,
Norton
,
E. G.
, and
Perry
,
F.
, 2008, “
Application of the Aventech AIMMS20AQ Airborne Probe for Turbulence Measurements During the Convective Storm Initiation Project
,”
Atmos. Chem. Phys.
,
8
, pp.
5449
5463
.
14.
Bögel
,
W.
, and
Baumann
,
R.
, 1991, “
Test and Calibration of the DLR Falcon Wind Measuring System by Maneuvers
,”
J. Atmos. Ocean. Technol.
,
8
, pp.
5
18
.
15.
Khelif
,
D.
,
Burns
,
S. P.
, and
Friehe
,
C. A.
, 1999, “
Improved Wind Measurements on Research Aircraft
,”
J. Atmos. Oceanic Technol.
,
16
, pp.
860
875
.
16.
Millane
,
R. P.
,
Stirling
,
G. D.
,
Brown
,
R. G.
,
Zhang
,
N.
,
Lo
,
V. L.
,
Enevoldson
,
E.
, and
Murray
,
J. E.
, 2010, “
Estimating Wind Velocities in Mountain Lee Waves Using Sailplane Flight Data
,”
J. Atmos. Oceanic Technol.
,
27
, pp.
147
158
.
17.
Holland
,
G. J.
,
McGeer
,
T.
, and
Youngren
,
H.
, 1992, “
Autonomous Aerosondes for Economical Atmospheric Soundings Anywhere on the Globe
,”
Bull. Am. Meteorl. Soc.
,
73
, pp.
1987
1998
.
18.
Holland
,
G. J.
,
Webster
,
P. J.
,
Curry
,
J. A.
,
Tyrell
,
G.
,
Gauntlett
,
D.
,
Brett
,
G.
,
Becker
,
J.
,
Hoag
,
R.
, and
Vaglienti
,
W.
, 2001, “
The Aerosonde Robotic Aircraft: A New Paradigm for Environmental Observations
,”
Bull. Am. Meteorl. Soc.
,
82
, pp.
889
901
.
19.
Ma
,
S. Q.
,
Chen
,
H. B.
,
Wang
,
G.
,
Pan
,
Y.
, and
Li
,
Q.
, 2004, “
A Miniature Robotic Plane Meteorological Sounding System
,”
Adv. Atmos. Sci.
,
21
, pp.
890
896
.
20.
Spiess
,
T.
,
Bange
,
J.
,
Buschmann
,
M.
, and
Vörsmann
,
P.
, 2007, “
First Application of the Meteorological Mini-UAV ’M2AV’
,”
Meteorol. Z.
,
16
, pp.
159
169
.
21.
Reuder
,
J.
,
Brisset
,
P.
,
Jonassen
,
M.
,
Mueller
,
M.
, and
Mayer
,
S.
, 2009, “
The Small Unmanned Meteorological Observer SUMO: A New Tool for Atmospheric Boundary Layer Research
,”
Meteorol. Z.
,
18
, pp.
141
147
.
22.
Van den Kroonenberg
,
A.
,
Martin
,
T.
,
Buschmann
,
M.
,
Bange
,
J.
, and
Vörsmann
,
P.
, 2008, “
Measuring the Wind Vector using the Autonomous Mini Aerial Vehicle M2AV
,”
J. Atmos. Ocean. Technol.
,
25
,
1969
1982
.
23.
Barber
,
S.
,
Chokani
,
N.
, and
Abhari
,
R. S.
, 2011,
“Effect of Wake Flow Non-Uniformity on Wind Turbine Performance and Aerodynamics,”
ASME-GT2011-46320.
24.
Jafari
,
S.
,
Chokani
,
N.
, and
Abhari
,
R. S.
, 2011,
“Terrain Effects on Wind Flow: Simulation with an Immersed Boundary Method,”
ASME-GT2011-46240, 2011.
25.
Mansour
,
M.
,
Kocer
,
G.
,
Lenherr
,
C.
,
Chokani
,
N.
, and
Abhari
,
R. S.
, 2011, “
Seven-Sensor Fast-Response Probe for Full-Scale Wind Turbine Flowfield Measurements
,”
J. Eng. Gas Turbines Power
,
133
, p.
081601
.
26.
Mueller
,
M.
, and
Drouin
,
A.
, 2007,
“Paparazzi - the Free Autopilot. Build your Own UAV,”
24th Chaos Communication Congress
, December.
27.
Kupferschmied
,
P.
,
Köppel
,
P.
,
Roduner
,
C.
, and
Gyarmathy
,
G.
, 2000, “
On the Development and Application of the Fast-Response Aerodynamic Probe System in Turbomachines—Part 1: The Measurement System
,”
ASME J. Turbomach.
,
122
, pp.
505
516
.
28.
Brücker
,
D.
, 2010,
“Assessment and Improvement of UAV Measurement System,”
Masters thesis, Laboratory for Energy Conversion, ETH Zurich.
29.
Behr
,
T.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
, 2006, “
A Probabilistic Uncertainty Evaluation Method for Turbomachinery Probe Measurements
,”
Proceedings 18th Symposium on Measuring Techniques in Turbomachinery
, Transonic and Supersonic Flow in Cascades and Turbomachines, September.
30.
Hau
,
E.
, 2006,
Wind Turbines: Fundamentals, Technologies, Applications, Economics
,
Springer-Verlag
,
Berlin
.
You do not currently have access to this content.