Room:
Diesel Hall
Topic:
B. Wind, wakes, turbulence and wind farms
Form of presentation:
Oral
Duration:
120 Minutes
Chaired by: J. Meyers, J. Peinke
16:30
Wind turbine wake tracking and its correlations with wind turbine monitoring sensors
Dr. Sandrine Aubrun | Université d'Orléans | France
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Authors:
Dr. Sandrine Aubrun | Université d'Orléans | France
Matthieu Boquet | France
Eulalio Torres Garcia | France
Nicolas Girard | France
Olivier Coupiac | France
Within the frame of the French project ANR SMARTEOLE, a 6-month measurement campaign has been set-up in the north of France to study the wake behaviour of two wind turbines, with an original set-up using: one ground based scanning LIght Detection And Ranging system (LIDAR), 2 nacelle-mounted LIDARs and a nacelle-embedded 2-axis inclinometer. The present paper will give first insight into the results and describe the different post-processing strategies used to prepare the data to be cross-correlated.
16:50
Wind Shear, Gust, and Yaw-Induced Dynamic Stall on Wind-Turbine Blades
Prof. David Rival | Queen's University | Canada
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Authors:
Prof. David Rival | Queen's University | Canada
Benen laBastide | Canada
Jaime Wong | Canada
This study examined the effect of a spanwise angle of attack gradient on the growth and stability of a dynamic stall vortex on a rotating blade. It was found that a spanwise angle of attack gradient induces a corresponding spanwise vorticity gradient, which, in combination with spanwise flow, results in a redistribution of circulation along the blade. Specifically, when replicating the angle of attack gradient experienced by a wind turbine at the 30% span position during a gust event, the spanwise vorticity gradient was aligned such that circulation was transported from areas of high circulation to areas of low circulation. This circulation redistribution behaviour describes a mechanism by which the fluctuating loads on a wind turbine are magnified, which is detrimental to turbine lifetime and performance.
17:10
Wind-tunnel simulation of stably stratified atmospheric boundary layers for the assessment of effects on wind turbines and wakes
Dr. Philip Hancock | University of Surrey | United Kingdom
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Authors:
Dr. Philip Hancock | University of Surrey | United Kingdom
Paul Hayden | United Kingdom
Results are presented of wind-tunnel simulations of a stable boundary layer of moderate surface condition and zero overlying inversion strength, as part of a programme of work investigating stable and convective wind conditions on wind turbines. The layer depth is matched to model scale by artificially thickening the boundary layer by means of flow generators (spires) at the working-section inlet. A non-uniform inlet temperature profile is essential in order to preclude the upper part of the layer retaining neutral conditions. The layer behaviour is sensitive to the prescribed form and care is needed in its specification. The results also show that the surface cooling should be started some distance downstream of the working-section inlet. The developed flow is closely horizontally homogeneous.
17:30
Model Wind Turbines Tested at Full-Scale Similarity
Marcus Hultmark | Princeton University | United States
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Authors:
Mark Miller | Princeton University | United States
Janik Kiefer | United States
Carsten Westergaard | United States
Marcus Hultmark | Princeton University | United States
The enormous length scales associated with modern wind turbines complicate any efforts to predict their performance and aerodynamics. Both experiments and numerical simulations are constrained by the large Reynolds numbers governing the full-scale aerodynamics. The limited fundamental understanding of Reynolds number effects in combination with the lack of empirical data affects our ability to predict, model, and design improved turbines and wind farms. A new experimental approach is presented, which utilizes a highly pressurized wind tunnel (up to 220 bar). It allows exact matching of the Reynolds numbers (no matter how it is defined), tip speed ratios, and Mach numbers on a geometrically similar, small-scale model. The design of a measurement and instrumentation stack to control the turbine and measure the loads in the pressurized environment is discussed. Results are then presented in the form of power coefficients as a function of Reynolds number and Tip Speed Ratio.