Wind turbine wake encounter by light aircraft

Abstract

The wake vortices generated by a wind turbine or a wind farm could interference with passing-by flying vehicles. A wind turbine wake study using engineering wake modelling, CFD, LIDAR field measurement and piloted flight simulation are carried out at University of Liverpool in cooperation with CAA, UK. A modified Kocurek wind turbine wake vortex model has been developed to simulate wind turbine wakes. It has been validated on the MEXICO wind turbine with the PIV wind tunnel measurements and the full CFD wake simulation results. This wake vortex model was applied to a WTN250 wind turbine, which has been installed near the East Midlands Airport, UK, where field measurements of wind turbine wake using LIDAR were carried out. The LIDAR measurement data were compared with the wake velocity fields generated by different wake modelling methods. The WTN250 wind turbine wake velocities generated by the Kocurek wake vortex model were integrated into an aircraft flight dynamic model to simulate a wind turbine wake encounter scenario, designed for a light aircraft approaching an airport, where a wind turbine was installed. The severity of the wind turbine wake encounter was investigated using piloted flight simulations. The simulation results suggest that the wake generated minor upsets on the aircraft and resulted a severity rating of B if only the disturbances caused by wake velocity deficits were taken into account.