“Blind test” calculations of the performance and wake development for a model wind turbine

This is a summary of the results from the “Blind test” Workshop on wind turbine wake modeling organized jointly by Nowitech and Norcowe in Bergen, October, 2011. A number of researchers were invited to predict the performance and the wake development for a model wind turbine that has been developed by and extensively tested at the Department of Energy and Process Engineering, NTNU. In the end, contributions were received from eight different groups using a wide range of methods, from standard Blade Element Momentum (BEM) methods to advanced fully resolved Computational Fluid Dynamics (CFD) and Large Eddy Simulation (LES) models. The range of results submitted was large, but the overall trend is that the current methods predict the power generation as well as the thrust force reasonably well, at least near the design operating conditions. But there is considerable uncertainty in the prediction of the wake velocity defect and turbulent kinetic energy distribution in the wake.

► Comparison between predictions and experimental data for a model wind turbine. ► 11 predictions from a total of 8 independent groups. ► Models ranging from simple Blade Element Momentum methods to full resolution Large Eddy Simulations. ► Performance and thrust forces predicted with reasonable accuracy. ► Wake development only predicted well with Large Eddy Simulation method.