2025 Nair Atmospheric Boundary Layer Wind Tunnel

Understanding the variation in wind properties with height is essential for simulating realistic atmospheric boundary layer (ABL) flow, particularly in the context of wind energy applications. This project aims to generate a neutral ABL in a wind tunnel facility at Imperial, following international wind standards and a specific marine profile typical of wind farms in the English Channel and North Sea. The methodology involves utilizing various ABL simulation devices, such as spires and roughness elements, to artificially replicate real-life ABLs, as conventional wind tunnels often lack sufficient length for natural development of the desired profiles. Key parameters such as vertical velocity gradient, turbulence intensity, and power spectral density of velocity fluctuations are critically assessed. Results indicate that the average wind speed at hub height significantly influences wind load characteristics, with higher turbulence levels leading to critical fluctuations in wind turbine rotational speeds, thereby increasing fatigue loads. Additionally, the research highlights the necessity of accurately reproducing hub height velocity and turbulence intensity to meet design requirements. This study underscores the complexities in ABL dynamics and provides a framework for effective monitoring and control of aerodynamic loading conditions essential for optimizing wind turbine performance.