Transient LES of an offshore wind turbine
Abstract. The estimation of the cost of energy of offshore wind farms has a high uncertainty, which is partly due to the lacking accuracy of information on wind conditions and wake losses inside of the farm. Wake models that aim on reducing the uncertainty by modeling the wake interaction of turbines for various wind conditions need to be validated with measurement data before they can be considered as a reliable estimator. A methodology is shown to create realistic transient wind conditions in a Large-Eddy-Simulation of a marine boundary layer interacting with an offshore wind turbine for a direct comparison of modeled with measured flow data. A mesoscale simulation is used for determining the boundary conditions of the model. The simulations of the ambient wind conditions and the wake simulation generally show a good agreement with measurements from a met mast and lidar measurements, respectively. Advanced metrics to describe the wake shape and development are derived from simulations and measurements but a quantitative comparison is difficult due to the scarcity and the low sampling rate of the available measurement data. The methodology presents a possibility to compare flow measurements with simulations. Due to the implementation of changing wind conditions in the LES it could be also beneficial for case studies of wind turbine and wind farm control.