Table of Contents
ISRN Mechanical Engineering
Volume 2012, Article ID 428671, 10 pages
http://dx.doi.org/10.5402/2012/428671
Research Article

Assessment of Two-Equation Turbulence Models and Validation of the Performance Characteristics of an Experimental Wind Turbine by CFD

1Ecole Polytechnique de Montreal, 2500 Chemin de Polytechnique, Montréal, QC, Canada H3T 1J4
2Université du Québec à Rimouski (UQAR), 300, Allée des Ursulines, Rimouski, QC, Canada G5L 3A1

Received 7 September 2011; Accepted 27 October 2011

Academic Editors: A. Z. Sahin and B. Yu

Copyright © 2012 Ece Sagol 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

The very first step in the simulation of ice accretion on a wind turbine blade is the accurate prediction of the flow field around it and the performance of the turbine rotor. The paper addresses this prediction using RANS equations with a proper turbulence model. The numerical computation is performed using a commercial CFD code, and the results are validated using experimental data for the 3D flow field around the NREL Phase VI HAWT rotor. For the flow simulation, a rotating reference frame method, which calculates the flow properties as time-averaged quantities, has been used to reduce the time spent on the analysis. A basic grid convergence study is carried out to select the adequate mesh size. The two-equation turbulence models available in ANSYS FLUENT are compared for a 7 m/s wind speed, and the one that best represents the flow features is then used to determine moments on the turbine rotor at five wind speeds (7 m/s, 10 m/s, 15 m/s, 20 m/s, and 25 m/s). The results are validated against experimental data, in terms of shaft torque, bending moment, and pressure coefficients at certain spanwise locations. Streamlines over the cross-sectional airfoils have also been provided for the stall speed to illustrate the separation locations. In general, results have shown good agreement with the experimental data for prestall speeds.