Int. J. Engineering Systems Modelling and Simulation, Vol. 5, Nos. 1/2/3, 2013 147 Copyright © 2013 Inderscience Enterprises Ltd. Evaluation of RANS/actuator disk modelling of wind turbine wake flow using wind tunnel measurements Jonathon Sumner* Physics Department, Dawson College, 3040 Sherbrooke St. W., Montreal, Quebec, H3Z 1A4, Canada E-mail: jsumner@dawsoncollege.qc.ca *Corresponding author Guillaume Espana Laboratoire PRISME, Université d’Orléans, 8, Rue Léonard de Vinci, F-45072 Orléans Cedex 2, France E-mail: gespana@laposte.net Christian Masson Département de Genie Mécanique, École de Technologie Supérieure, 1100, Rue Notre-Dame Ouest Montréal, Québec, H3C 1K3, Canada Fax: +1-514-396-8530 E-mail: christian.masson@etsmtl.ca Sandrine Aubrun Laboratoire PRISME, Université d’Orléans, 8, Rue Léonard de Vinci, F-45072 Orléans Cedex 2, France Fax: +33-(0)2-38-41-73-83 E-mail: sandrine.aubrun@univ-orleans.fr Abstract: Wake modelling plays a central role in wind farm planning through the evaluation of losses, the prediction of the energy yield, and the estimation of turbine loads. These models must be reasonably accurate – to minimise financial risk – and yet economical so that many configurations can be tested within reasonable time. While many such models have been proposed, an especially attractive approach is based on the solution of the Reynolds-averaged Navier-Stokes equations with two-equation turbulence closure and an actuator disk representation of the rotor. The validity of this approach and its inherent limitations however remain to be fully understood. To this end, detailed wind tunnel measurements in the wake of a porous disk (with similar aerodynamic properties as a turbine rotor) immersed in a uniform flow are compared with the predictions of several closures. Agreement with measurements is found to be excellent for all models. This unexpected result seems to derive from a fundamental difference in the turbulent nature of the homogeneous wind tunnel flow and that of the atmospheric boundary layer. Keywords: wind turbine wake; turbulence modelling; wind tunnel; computational fluid dynamics; actuator disk. Reference to this paper should be made as follows: Sumner, J., Espana, G., Masson, C. and Aubrun, S. (2013) ‘Evaluation of RANS/actuator disk modelling of wind turbine wake flow using wind tunnel measurements’, Int. J. Engineering Systems Modelling and Simulation, Vol. 5, Nos. 1/2/3, pp.147–158. Biographical notes: Jonathon Sumner completed a Bachelor of Engineering Science at Western University (Canada) in 2003 and a Master of Mechanical Engineering at the École de Technologie Supérieure (Canada) in 2006. He recently earned a PhD from the École de Technologie Supérieure working in the NEAT research group. His expertise is in the simulation of atmospheric flows, especially in the context of wind resource assessment and wind farm power performance evaluation. He is currently a faculty member of the Physics Department at Dawson College (Canada). After completing a master’s degree in aerodynamics and aeroacoustics, Guillaume Espana arrived at the PRISME Laboratory of the University of Orléans (France) in 2006. There, he carried out wind tunnel studies on the steady and unsteady characteristics of wind turbine wakes and was awarded a PhD in 2009 based on this work. Following his doctorate, he taught courses in fluid mechanics and thermodynamics at the University of Orléans. He is presently a project and sales manager for the wind turbine manufacturer Enercon GmbH.