Computational Fluid Dynamics Turbulence and Wake Study of a Utility-Scale Rotating Three-Blade Horizontal Axis Wind Turbine

Abstract

Wind turbines deployed in utility scale wind farms can help to meet future energy demands and reduce carbon dioxide emissions by reducing energy needs from fossil fuels. Wind turbines, however, produce downstream wakes and turbulence. In wind farms such turbulence can negatively impact power production of downstream turbines. It is critical, therefore, to understand this downstream turbulence, but this is challenging. Wind farm layouts are costly and mandate advanced analysis and sophisticated simulations be done to define a wind farm configuration long-before its construction. This is usually done using high-speed computers, and even super computers, to simulate and analyze downstream conditions. In this work the successful deployment of Computational Fluid Dynamics (CFD) using a desktop workstation to study downstream turbulence and wakes of a single utility-scale, rotational three-blade horizontal axis wind turbine (HAWT) are presented. A three-dimensional flow field assuming incompressible flow and unsteady state SST k-ω (two equation) turbulence model was constructed using an unstructured grid around an operational typical utility size HAWT with a rotor hub elevation of 80 meters and a blade length of 40 meters rotating at 18 RPMs. Various wind velocities of up to 25 meters per second providing pressures and velocities were successfully studied.