Suppresing Vortex Induced Vibrations of Wind Turbine blades with flaps

The present paper describes an exploratory work aiming to analyze the impact oftrailing edge flaps activation on Vortex Induced Vibrations (VIV) suppression. A computationalstudy of the VIV of the AVATAR rotor blade, a 10MW design suitable for offshore locations,was performed. A Fluid Structure Interaction (FSI) approach was adopted for the simulations,coupling an Improved Delayed Detached Eddy Simulations (IDDES) flow solver with a beam-based structural model.

Initial simulations based on the clean geometry identified significantedgewise VIV for certain free stream velocity and flow inclination angles. The inflow conditionsshowing the maximum amplitude of blade vibrations were used in order to test several trailingedge flap geometries and operating angles.

The best flap configuration found in that parametricstudy managed to suppress the VIV phenomenon. However, when assessing a wider range ofinflow conditions, the amplitudes of vibration of the blade equipped with flaps were found tobe equivalent to the ones obtained for its clean counterpart. It is therefore concluded that are-calibration of the flap operating angle should be required in order to adapt it to the consideredwind speed and wind direction.