Full-Scale Wind Turbine Near-Wake Measurements Using an Instrumented Uninhabited Aerial Vehicle

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.

[1]  G. J. Taylor,et al.  Wake and performance measurements on the Lawson-Tancred 17 m horizontal-axis windmill , 1983 .

[2]  E. G. Norton,et al.  Application of the Aventech AIMMS20AQ airborne probe for turbulence measurements during the Convective Storm Initiation Project , 2007 .

[3]  Li Qiang,et al.  A miniature robotic plane meteorological sounding system , 2004 .

[4]  R. Abhari,et al.  Effect of Wake Flow Nonuniformity on Wind Turbine Performance and Aerodynamics , 2013 .

[5]  Reza S. Abhari,et al.  Terrain Effects on Wind Flow: Simulations With an Immersed Boundary Method , 2011 .

[6]  G. J. Holland,et al.  The Aerosonde Robotic Aircraft: A New Paradigm for Environmental Observations , 2001 .

[7]  Reza S. Abhari,et al.  Seven-Sensor Fast-Response Probe for Full-Scale Wind Turbine Flowfield Measurements , 2011 .

[8]  Harry D. Kambezidis,et al.  Wake measurements behind a horizontal-axis 50 kW wind turbine , 1990 .

[9]  D. N. Asimakopoulos,et al.  A field study of the wake behind a 2 MW wind turbine , 1988 .

[10]  Sean P. Burns,et al.  Improved Wind Measurements on Research Aircraft , 1999 .

[11]  James E. Murray,et al.  Estimating Wind Velocities in Mountain Lee Waves Using Sailplane Flight Data , 2010 .

[12]  Per Jonas Petter Lindelöw,et al.  Testing and comparison of lidars for profile and turbulence measurements in wind energy , 2008 .

[13]  Y. Yongqiang,et al.  Numerical Simulation of Global Temperature Change during the 20th Century with the IAP/LASG GOALS Model , 2004 .

[14]  Reza S. Abhari,et al.  A probabilistic uncertainty evaluation method for turbomachinery probe measurements , 2006 .

[15]  Panagiotis Papageorgas,et al.  An experimental study of the near-wake structure of a wind turbine operating over complex terrain , 1995 .

[16]  G. W. Gyatt,et al.  Wake structure measurements at the Mod-2 cluster test facility at Goodnoe Hills , 1983 .

[17]  Antoine Drouin,et al.  Paparazzi - The free autopilot : build your own UAV , 2007 .

[18]  Reza S. Abhari,et al.  Effect of Wake Flow Non-Uniformity on Wind Turbine Performance and Aerodynamics , 2011 .

[19]  R. Baumann,et al.  Test and Calibration of the DLR Falcon Wind Measuring System by Maneuvers , 1991 .

[20]  Tad McGeer,et al.  Autonomous aerosondes for economical atmospheric soundings anywhere on the globe , 1992 .

[21]  Jens Bange,et al.  First application of the meteorological Mini-UAV 'M2AV' , 2007 .

[22]  D. N. Axford,et al.  On the Accuracy of Wind Measurements Using an Inertial Platform in an Aircraft, and an Example of a Measurement of the Vertical Mesostructure of the Atmosphere. , 1968 .

[23]  J. Bange,et al.  Measuring the Wind Vector Using the Autonomous Mini Aerial Vehicle M2AV , 2008 .

[24]  Erich Hau,et al.  Wind Turbines: Fundamentals, Technologies, Application, Economics , 1999 .

[25]  Stel Nathan Walker,et al.  Wake measurements behind a large horizontal axis wind turbine generator , 1984 .

[26]  Christian Roduner,et al.  On the Development and Application of the Fast-Response Aerodynamic Probe System in Turbomachines—Part 1: The Measurement System , 2000 .

[27]  Pascal Brisset,et al.  The Small Unmanned Meteorological Observer SUMO: A new tool for atmospheric boundary layer research , 2009 .

[28]  Torben Mikkelsen,et al.  Remote sensing the wind using lidars and sodars , 2007 .

[29]  J. C. Barnard,et al.  Observations of wind turbine wakes and surface roughness effects on wind flow variability , 1990 .

[30]  H. Jørgensen,et al.  Wind lidar evaluation at the Danish wind test site in Høvsøre , 2006 .