Numerical simulation of the aerodynamic performance of an H-rotor

NUMERICAL SIMULA nON OF THE AERODYNAMIC PERFORMANCE OF AN H-ROTOR YanChen August 1 st, 2011 Vertical axis wind turbines (VAWTs) are devices to convert wind energy into electricity. Unlike horizontal axis wind turbines (HA WT) where the main rotor shaft is set horizontally, VAWTs use vertical rotor shaft. Unlike HAWTs, VAWTs can be effectively used in urban environment where flow is characterized with unsteadiness and turbulence. The efficiency of the VA WTs highly depends on the aerodynamics of the wind blades. In this thesis we study the aerodynamics of the H-rotor, one type ofVAWTs using computational fluid dynamics methods. Two different approaches are used in this study. One is based on direct numerical simulation (DNS) method and another is based on Reynolds averaged Navier-Stoke (RANS) model. For DNS study we solve the incompressible Navier-Stokes equations with a CFD package, OVERTURE. An overlapping moving grids technique is employed to handle the rotation of the wind turbine. For RANS simulation we used a commercial CFD package ANSYS-Fluent. The