Design and analysis of small-scale vertical axis wind turbine

This study presents a combined experimental, computational and theoretical study of the aerodynamic performance of a small scale straight bladed vertical axis wind turbine (SB-VAWT). The wind tunnel tests were carried out to study the overall performance of the turbine using three different airfoil profiles. It is shown experimentally that blade profile has significant effect on its performance. Unsteady-flow computations were performed helping to understand the aerodynamics of the turbines´ performance. The two- and three-dimensional unsteady flow field simulation around the turbines were performed using time accurate Reynolds Averaged Navier Stokes (RANS) solver. Interesting features about the dynamic stall around the blades and the interaction of the blade wakes with the following blades were observed. Comparisons of the 2D and 3D simulations highlight the strong 3D effects, including the blade tip vortices and effects. Wind tunnel measurements were carried out at low tip-speed ratios (TSRs) to study the self-starting capability initially, while a motor was used to study the full range of TSR performance of small scale turbine model. Comparisons of the overall turbine performance coefficient have been studied through wind tunnel measurements, simulations and theoretical analysis. Significant tunnel wall effects were observed from simulation results and strongly influence the overall performance results.