VALIDATION OF A FREE-VORTEX WAKE MODEL FOR WIND TURBINES IN YAWED FLOW

A time-accurate free-vortex wake model has been used to predict the skewed wake geometry behind an upwind wind turbine in yawed flow over a range of yaw angles and tip speed ratios. The predicted tip vortex positions compared well with flow visualization measurements of the tip vortex positions found in the experiments. Increasing wake skewness was found to cause the wake to roll up along its edges. Good agreement was achieved between the predicted and measured turbine thrust for the entire range of conditions used in the experiment.

[1]  Tonio Sant,et al.  Measurement and Modelling of Tip Vortex Paths in the Wake of a HAWT under Yawed Flow Conditions , 2005 .

[2]  J. Gordon Leishman,et al.  Accuracy of the Induced Velocity from Helicoidal Wake Vortices Using Straight-Line Segmentation , 2005 .

[3]  G. Vatistas,et al.  A simpler model for concentrated vortices , 1991 .

[4]  Maureen Hand,et al.  NREL Unsteady Aerodynamics Experiment in the NASA-Ames Wind Tunnel: A Comparison of Predictions to Measurements , 2001 .

[5]  Ian Grant,et al.  A DPIV study of the trailing vortex elements from the blades of a horizontal axis wind turbine in yaw , 2000 .

[6]  F. N. Coton,et al.  The prediction of horizontal axis wind turbine performance in yawed flow using an unsteady prescribed wake model , 1999 .

[7]  J. Gordon Leishman,et al.  Challenges in Modeling the Unsteady Aerodynamics of Wind Turbines , 2002 .

[8]  David J. Laino,et al.  Continued Validation of the AeroDyn Subroutines Using NREL Unsteady Aerodynamics Experiment Data , 2002 .

[9]  Ian Grant,et al.  Optical vortex tracking studies of a horizontal axis wind turbine in yaw using laser-sheet, flow visualisation , 1997 .

[10]  A. T. Conlisk,et al.  Formation of a Rotor Tip Vortex , 2002 .

[11]  J. Sørensen,et al.  Analysis of wake states by a full‐field actuator disc model , 1998 .

[12]  J. Sørensen,et al.  Wind turbine wake aerodynamics , 2003 .

[13]  J. Gordon Leishman,et al.  Role of Filament Strain in the Free-Vortex Modeling of Rotor Wakes , 2004 .

[14]  P. B. S. Lissaman,et al.  Applied Aerodynamics of Wind Power Machines , 1974, Renewable Energy.

[15]  J. G. Leishman,et al.  Correlation of Helicopter Rotor Tip Vortex Measurements , 2000 .

[16]  Jason Jonkman,et al.  FAST User's Guide , 2005 .

[17]  Frank N. Coton,et al.  A high resolution tower shadow model for downwind wind turbines , 2001 .

[18]  J. Gordon Leishman,et al.  ACCURACY OF THE INDUCED VELOCITY OF WIND TURBINE WAKES USING VORTEX SEGMENTATION , 2004 .

[19]  J. Schepers.  An engineering model for yawed conditions, developed on basis of wind tunnel measurements , 1999 .

[20]  Scott Schreck,et al.  Wind Tunnel Testing of NREL's Unsteady Aerodynamics Experiment , 2001 .

[21]  J. Gordon Leishman,et al.  A Generalized Model for Transitional Blade Tip Vortices , 2004 .

[22]  J. Gordon Leishman,et al.  STABILITY OF METHODS IN THE FREE-VORTEX WAKE ANALYSIS OF WIND TURBINES , 2004 .

[23]  D. Kocurek,et al.  Lifting surface performance analysis for horizontal axis wind turbines , 1987 .

[24]  A. Hansen,et al.  Aerodynamics of Horizontal-Axis Wind Turbines , 1993 .

[25]  J. Gordon Leishman,et al.  Free-Vortex Filament Methods for the Analysis of Helicopter Rotor Wakes , 2002 .

[26]  Leishman,et al.  The Role of Filament Stretching in the Free-Vortex Modeling of Rotor Wakes , 2002 .

[27]  Niels N. Sørensen,et al.  Navier-Stokes predictions of the NREL phase VI rotor in the NASA Ames 80-by-120 wind tunnel , 2002 .

[28]  J. Gordon Leishman,et al.  COMPARISON OF MOMENTUM AND VORTEX METHODS FOR THE AERODYNAMIC ANALYSIS OF WIND TURBINES , 2005 .