Large eddy simulation of turbine loading and performance in a wind farm

•We present an aeroelastic code coupled to an LES solver for wind farm modelling.•Turbine control is included to allow transient above- and below-rated simulation.•Turbine wakes, loads, power fluctuation and control utitlisation are examined.•Wake meandering is observed and found to influence local onset wind directions.•A simulation including yaw control is also presented with significant actuation.

We investigate multiple wind turbines operating in a small turbine array using a coupled LES/aero-elastic method. Wake interaction effects are assessed for multiple wind-speeds, with performance of the wind farm quantified, including measurement of efficiency, controller utilisation and loading effects. Power losses are shown to peak at over 40% for the full-wake case, with increased power fluctuation and control actuator usage noted at downwind turbine locations. Spectral analysis of the wake indicates a broad peak meandering frequency. Dynamic yaw control has also been included in the simulations – a first for LES simulation of wind farms – with significant yaw actuation observed due to local wind direction changes despite a constant global wind direction.