Posters

Abstract

In response to the growing global demand for clean energy, wind power has become an essential component of the renewable energy portfolio. Due to the limited availability of wind resources in flat terrains, onshore wind farm site selection is increasingly shifting toward mountainous regions. Sometimes the construction of wind farms in complex terrain requires semi-excavation techniques to level turbine platforms, given administrative and environmental constraints. These high-slope structures resulting from semi-excavation significantly alter wind flow distribution around turbine platforms, potentially affecting turbine performance, structural loads, and operational stability. This study focuses on two turbine platforms at an operational wind farm in Yunnan Province, China, to investigate wind flow distribution under various semi-excavation configurations through computational fluid dynamics (CFD) simulations. Due to the highly complex topography of semi-excavation platforms, this study adopts an unstructured grid with a one-meter resolution, in contrast to the decameter-level resolution structured grid which is commonly used in wind resource assessment. By integrating LiDAR measurements for validation, the study identifies optimal CFD parameters, including atmospheric stability, surface roughness, and vegetation conditions, tailored to the wind farm's specific terrain. Furthermore, a comparative analysis across three scenarios—semi-excavation versus original terrain, semi-excavation versus full-excavation, and full-excavation versus original terrain—reveals significant variations in wind flow parameters (including speed-up factor, turbulence intensity, inflow angle and deviation) related to both height and distance from the semi-excavation slope. The findings provide valuable insights for optimizing wind farm site selection and construction strategies in mountainous areas, ultimately contributing to enhanced turbine performance and long-term operational efficiency.