scholarly journals Open Access Wind Tunnel Measurements of a Downwind Free Yawing Wind Turbine

2016 ◽  
Vol 753 ◽  
pp. 072013 ◽  
Author(s):  
David Verelst ◽  
Torben Larsen ◽  
Jan-Willem van Wingerden
Keyword(s):  
Open Access ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Tunnel Measurements

scholarly journals Linear stability analysis of wind turbine wakes performed on wind tunnel measurements

2013 ◽  
Vol 737 ◽  
pp. 499-526 ◽  
Author(s):  
G. V. Iungo ◽  
F. Viola ◽  
S. Camarri ◽  
F. Porté-Agel ◽  
F. Gallaire
Keyword(s):  
Stability Analysis ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Rotational Velocity ◽  
Base Flow ◽  
Wind Tunnel Measurements ◽  
Turbine Wake ◽  
Wind Turbine Wake

AbstractWind tunnel measurements were performed for the wake produced by a three-bladed wind turbine immersed in uniform flow. These tests show the presence of a vorticity structure in the near-wake region mainly oriented along the streamwise direction, which is denoted as the hub vortex. The hub vortex is characterized by oscillations with frequencies lower than that connected to the rotational velocity of the rotor, which previous works have ascribed to wake meandering. This phenomenon consists of transversal oscillations of the wind turbine wake, which might be excited by the vortex shedding from the rotor disc acting as a bluff body. In this work, temporal and spatial linear stability analyses of a wind turbine wake are performed on a base flow obtained with time-averaged wind tunnel velocity measurements. This study shows that the low-frequency spectral component detected experimentally matches the most amplified frequency of the counter-winding single-helix mode downstream of the wind turbine. Then, simultaneous hot-wire measurements confirm the presence of a helicoidal unstable mode of the hub vortex with a streamwise wavenumber roughly equal to that predicted from the linear stability analysis.

The Effect of Distributed Roughness on the Power Performance of Wind Turbines

2010 ◽  
Author(s):  
G. Pechlivanoglou ◽  
S. Fuehr ◽  
C. N. Nayeri ◽  
C. O. Paschereit
Keyword(s):  
Steady State ◽  
Wind Tunnel ◽  
Numerical Simulations ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Power Production ◽  
Aerodynamic Performance ◽  
Power Performance ◽  
Turbine Performance ◽  
Wind Tunnel Measurements

The effects of distributed roughness on wind turbines are extensively investigated in this paper. The sources of roughness are identified and analyzed and their effects on airfoil are estimated from simulations and measured with wind tunnel measurements. In addition to the environmental and manufacturing induced roughness, several forms of roughness-related shape deviations are investigated and their effects on the aerodynamic performance of airfoils is qualitatively predicted through numerical simulations. The actual effects of roughness on wind turbine performance are also presented through power production measurements of wind turbines installed in sandy environments. These measurements are correlated with simulated power predictions, utilizing a steady state BEM code.

Experimental and Numerical Investigation of Inflow Turbulence on the Performance of Wind Turbine Airfoils

2013 ◽  
Author(s):  
O. Eisele ◽  
G. Pechlivanoglou ◽  
C. N. Nayeri ◽  
C. O. Paschereit
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Tunnel Test ◽  
Wind Turbine Blade ◽  
Two Dimensional ◽  
Airfoil Surface ◽  
Wind Tunnel Measurements ◽  
Inflow Turbulence ◽  
The Impact

Wind turbine blade design is currently based on the combination of a plurality of airfoil sections along the rotorblade span. The two-dimensional airfoil characteristics are usually measured with wind tunnel experiments or computed by means of numerical simulation codes. The general airfoil input for the calculation of the rotorblade power characteristics as well as the subsequent aerodynamic and aeroelastic loads are based on these two-dimensional airfoil characteristics. In this paper, the effects of inflow turbulence and wind tunnel test measurement deviations are investigated and discussed, to allow considerations of such effects in the rotorblade design process. The results of CFD simulations with various turbulence models are utilized in combination with wind tunnel measurements in order to assess the impact of such discrepancies. It seems that turbulence, airfoil surface roughness and early transition effects are able to contribute significantly to the uncertainty and scattering of measurements. Various wind tunnel facilities generate different performance characteristic curves, while grid-generated turbulence is generally not included in the wind tunnel measurements during airfoil characterization. Furthermore the correlation of grid-generated wind tunnel turbulence with the atmospheric turbulence time and length scales is not easily achieved. All the aforementioned uncertainties can increase the performance scattering of current wind turbine blade designs as well as the generated aeroelastic loads. A brief assessment of the effect of such uncertainties on wind turbine performance is given at the last part of this work by means of BEM simulations on a wind turbine blade.

Smart dynamic rotor control using active flaps on a small-scale wind turbine: aeroelastic modeling and comparison with wind tunnel measurements

Wind Energy ◽  
2012 ◽  
pp. n/a-n/a ◽  
Author(s):  
T.K. Barlas ◽  
W. van Wingerden ◽  
A.W. Hulskamp ◽  
G.A. M. van Kuik ◽  
H.E. N. Bersee
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Small Scale ◽  
Wind Tunnel Measurements ◽  
Rotor Control

scholarly journals Localization of wind turbine noise using a microphone array in wind tunnel measurements

Wind Energy ◽  
2021 ◽  
Author(s):  
Christof Ocker ◽  
Esther Blumendeller ◽  
Philipp Berlinger ◽  
Wolfram Pannert ◽  
Andrew Clifton
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Microphone Array ◽  
Wind Turbine Noise ◽  
Wind Tunnel Measurements

scholarly journals Large-Eddy Simulation of Yawed Wind-Turbine Wakes: Comparisons with Wind Tunnel Measurements and Analytical Wake Models

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4574 ◽  
Author(s):  
Mou Lin ◽  
Fernando Porté-Agel
Keyword(s):  
Wind Tunnel ◽  
Large Eddy Simulation ◽  
Wind Turbine ◽  
Wind Farms ◽  
Disk Model ◽  
Actuator Disk ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Wind Tunnel Measurements ◽  
Tangential Forces

In this study, we validated a wind-turbine parameterisation for large-eddy simulation (LES) of yawed wind-turbine wakes. The presented parameterisation is modified from the rotational actuator disk model (ADMR), which takes account of both thrust and tangential forces induced by a wind turbine based on the blade-element theory. LES results using the yawed ADMR were validated with wind-tunnel measurements of the wakes behind a stand-alone miniature wind turbine model with different yaw angles. Comparisons were also made with the predictions of analytical wake models. In general, LES results using the yawed ADMR are in good agreement with both wind-tunnel measurements and analytical wake models regarding wake deflections and spanwise profiles of the mean velocity deficit and the turbulence intensity. Moreover, the power output of the yawed wind turbine is directly computed from the tangential forces resolved by the yawed ADMR, in contrast with the indirect power estimation used in the standard actuator disk model. We found significant improvement in the power prediction from LES using the yawed ADMR over the simulations using the standard actuator disk without rotation, suggesting a good potential of the yawed ADMR to be applied in LES studies of active yaw control in wind farms.

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