Large-eddy simulation of wind farm wake behavior and power efficiency: Effects of atmospheric stratification and staggered configurations

Wake interference between wind turbine arrays significantly affects wind farm performance. While staggered configurations, both laterally and vertically, have shown potential in mitigating this interference, their performance under different atmospheric stratifications remains ambiguous. This study uses large eddy simulation (LES) to evaluate the advantages of staggered configurations over the conventional aligned configuration, focusing on their ability to reduce turbulence-induced instability and improve energy efficiency, underscoring their potential applicability in real-world scenarios. Simulation results indicate that the laterally-staggered configuration, which increases the effective distance between consecutive turbines, allows turbine wakes to experience lower velocity deficits and turbulence intensity when interacting with downstream turbines, thereby improving aerodynamic performance. However, the performance of the laterally-staggered configuration is highly sensitive to changes in stratification regimes due to the modulating effects of atmospheric stratification on the internal flow within the wind farm, altering the inherent power generation patterns under different stratification regimes. Nonetheless, the laterally-staggered configuration improved power generation by 36% and reduced turbulence intensity inside the wind farm by 11.5%. In contrast, the vertically-staggered configurations demonstrate minimal sensitivity to stratification changes, with a relatively larger hub height difference (2Hd) between turbines improving power generation (up to 18.4%) and reducing turbulence intensity (up to 5.7%).