A STUDY OF THE NEAR WAKE STRUCTURE OF A WIND TURBINE COMPARING MEASUREMENTS FROM LABORATORY AND FULL-SCALE EXPERIMENTS

Wake flow measurements have been performed using the technique of part icle image velocimetry (PIV) at stations downstream from a model wind turbine rotor, and evaluated against experimental data from two full-s cale machines. Comparisons include both mean velocity and turbulent in tensity cross-wake profiles at a range of tip speed ratios. The applic ation of PIV to the study of wind turbine wakes is described in detail , including the steps required to ensure appropriate and accurate simu lation of the flow field conditions. The results suggest that the PIV method is a potentially useful tool in the investigation of detailed w ake how, though significant differences are observed between wake velo city deficits at full- and model scale. These are discussed with regar d to scale effect, the influence of terrain, model similarity, and the phenomenon of wake meandering and effective cross-wake smoothing. Cop yright (C) 1996 Elsevier Science Ltd.