Incorporating realistic geophysical effects of mean wind from LIDAR measurements in large eddy simulation of wind turbine arrays

The present paper aims at performing Large Eddy Simulation of a 3 × 3 wind turbine array in atmospheric boundary layer, by incorporating realistic large scale geophysical effects, such as the variation in mean wind flux (gusts) and wind direction (wind veer) from the data obtained by field measurements. The purpose of this study is to understand the effect of realistic winds on turbulence and wake interactions, and also on the power generated by the wind turbines. The wind turbines are modelled using a state-of-the- art reduced order actuator line (AL) model, which is computationally more efficient than resolving the blades of the turbine. The inflow conditions are generated by spectrally interpolating the data from a precursor Atmospheric Boundary Layer (ABL) simulation and incorporating the geophysical effects obtained from LIDAR scans to adjust the wind flux and wind direction from the precursor simulations, as appropriate. Additionally, we also present a comparison of the above approach with an LES performed with a standard turbulent inflow to further understand the influence of the geophysical effects on large-scale coherence and subsequently on wind power. Furthermore, the knowledge of the influence of geophysical effects in a long term is expected to improve decision making capabilities in wind farm optimization algorithms and contribute to the design and validation of data assimilation algorithms.