Validation of Chaviaro Poulos and Hansen Stall Delay Model in the Case of Horizontal Axis Wind Turbine Operating in Yaw Conditions

Abdelfattah Bouatem, Ahmed Al Mers

Department of Energetic, Moulay Ismail University, Meknes, Morocco.
Department of Mechanical Engineering, Moulay Ismail University, Meknes, Morocco.

DOI: 10.4236/epe.2013.51003                

Abstract

Operating in natural wind field, the horizontal axis wind turbines are subject to cyclical variation of aerodynamic loads. This cyclical loads fluctuation is a result of two aerodynamic phenomenon: the first one is the advancing and retreating blade effect; the second one is related to the cyclical variation of induced velocity at the rotor plane. In these operating conditions, the correct prediction of this load variation is necessary to predict some important parameters linked to the fatigue and stability of free yawing turbines. The main objective of the present study is the evaluation of the azimuthal variation of normal force at different radial positions. To model the problem, the blade element momentum theory is used and wind turbine is supposed operate in yaw conditions. The aerodynamic coefficients are corrected using Chaviaropoulos and Hansen model to take into account the phenomenon of stall delay. A computer code was developed to obtain the numerical values and results are compared with measurements performed in the NASA Ames wind tunnel.

Keywords

Wind Turbine; Wake; Yaw; Stall; Stall Delay; Skewed Wake; Renewable Energy

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	R. E. Froude, “On the Part Played in Propulsion by Difference in Pressure,” Transactions of the Institution of Naval Architects, 1889, pp. 390-423.
[2]	W. J. M. Rankine, “On the Mechanical Principles of the Action of Propellers,” Transactions of the Institution of Naval Architects, 1865, pp. 13-39.
[3]	H. Glauert, “Airplane Propellers,” In: W. F. Durand, Eds., Aerodynamic Theory, Vol. 4, 1934, p. 332.
[4]	P. J. Moriartry and A. C. Hansen, “Aerodyn Theory Manual,” National Renewable Energy Laboratory, 2005, NREL TP-500-36881.
[5]	J. Hernandez and A. Crespo, “Aerodynamics Calculation of the Performance of Horizontal Axis Wind Turbines and Comparison with Experimental Results,” Wind Engineering, Vol. 11, No. 4, 1987, pp. 177-187.
[6]	S. P. Breton, “Study of the Stall Delay Phenomenon and of Wind Turbine Blade Dynamics Using Numerical Approaches and NREL’s Wind Tunnel Tests,” Doctoral Thesis, Norwegian University of Science and Technology, Trondheim, 2008.
[7]	J. G. Shepers, “Final Report of IEA Annex XX: Comparison between Calculations and Measurements on a Wind Turbine in Yaw in the NASA-Ames Wind Tunnel,” ECN-E-07-072.