Study on aerodynamic performance of a straight-bladed Vertical Axis Wind Turbine by CFD simulations

Abstract

The flow around the vertical axis wind turbine is a three dimensional and complicated flow field due to the relative inflow angle to the rotor blade depending on the azimuth angle and the detour of the flow in the vertical direction. This study aimed to clarify the three dimensional effect occurred in the vertical axis wind turbine using numerical analysis. In this study, three dimensional steady analysis of flow field around a vertical axis wind turbine using CFD was performed. It is verified by considering the load in the span-wise direction of the blade as the influence of the three dimensional flow field on the rotor blade surface. The three-dimensional nature of the flow field around the vertical axis wind turbine was verified by examining the amount of circulation around the rotor blades and the wake vortex generated from the rotor blades. When the rotor blades pass the upstream side, the amount of circulation around the rotor blades becomes the largest at the center height of the blades and decreases as approaching the blade tip. The upstream flow into the wind turbine bypasses in the vertical direction of the wind turbine as it approaches the wind turbine due to the thrust generated on the rotor blade and has a velocity component in the vertical direction.