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Modelling and Simulation in Engineering
Volume 2010, Article ID 860814, 11 pages
http://dx.doi.org/10.1155/2010/860814
Research Article

Numerical Simulation of Tower Rotor Interaction for Downwind Wind Turbine

Masdar Institute of Science and Technology, P.O. Box 54224, Abu Dhabi, UAE

Received 24 July 2009; Revised 13 May 2010; Accepted 8 June 2010

Academic Editor: Andreas Tolk

Copyright © 2010 Isam Janajreh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Downwind wind turbines have lower upwind rotor misalignment, and thus lower turning moment and self-steered advantage over the upwind configuration. In this paper, numerical simulation to the downwind turbine is conducted to investigate the interaction between the tower and the blade during the intrinsic passage of the rotor in the wake of the tower. The moving rotor has been accounted for via ALE formulation of the incompressible, unsteady, turbulent Navier-Stokes equations. The localized , , and are computed and compared to undisturbed flow evaluated by Panel method. The time history of the , aerodynamic forces ( and ), as well as moments were evaluated for three cross-sectional tower; asymmetrical airfoil (NACA0012) having four times the rotor's chord length, and two circular cross-sections having four and two chords lengths of the rotor's chord. 5%, 17%, and 57% reductions of the aerodynamic lift forces during the blade passage in the wake of the symmetrical airfoil tower, small circular cross-section tower and large circular cross-section tower were observed, respectively. The pronounced reduction, however, is confined to a short time/distance of three rotor chords. A net forward impulsive force is also observed on the tower due to the high speed rotor motion.