Comparisons of wake models profiles with LiDAR data measured downstream from an operating onshore wind turbine

Abstract

This study analyzes the performance of Park, Frandsen, and Larsen models to simulate wake development downstream from a wind turbine for freestream wind velocities ranging from 5 to 10 m/s. Analyses are performed in terms of normalized freestream velocity recovery for a longitudinal centerline downstream from the turbine and normalized wind velocity profiles for cross-sections located 500 and 700 m downstream from the wind turbine. Simulated results are compared with high resolution LiDAR data measured during operation of a North American wind farm. Comparisons of longitudinal profiles demonstrate that Larsen and Frandsen models provide the best agreement with measured data for the case of 5 m/s freestream wind velocity, whereas Park model performs best for the 6–9 m/s freestream wind velocity bins. Post-processing of measured data indicates asymmetry of wake profiles at the selected cross-sections. At these locations, Larsen model accurately predicts the west side of normalized velocity profiles, whereas Park and Frandsen models only predict the velocity recovery at the wake centerline.