Influence of Layouts on the Fully-developed Wind-Turbine Array Boundary Layer

When the streamwise scale of the wind farm exceeds an order of magnitude of the atmospheric boundary layer height, it becomes the fully-developed wind farm, which is an important theoretical model to study the flow mechanisms of large wind power plants. However, existing studies are only focused on the regular wind farm layout, and the influence of the layout on the flow characteristics, vertical structure, and mean kinetic energy budget of the atmospheric boundary layer is still not well understood. To this end, we utilize high-fidelity large-eddy simulation to investigate the influence of layout with different wind turbine densities. The results show that layouts can significantly influence the local flow features around wind turbines and flow inhomogeneity of the wind farm, but the influence is limited to the inner layer and wake layer. With the same wind farm density, the mean relative equivalent roughness height difference is only 6.5% and the power harvested difference by wind turbines is about 5.1% between different layouts.