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. (C) 2016 Elsevier Ltd. All rights reserved.