A straight-bladed vertical axis turbine for wave energy conversion: Effect of guide vane position on the performance

Abstract

A straight-bladed vertical axis turbine for wave energy conversion has been proposed in order to develop a novel air turbine suitable for an oscillating water column based on a wave energy plant. This study aims at investigating the effect of guide vane position on the performance of a straight-bladed vertical axis turbine. The experimental study was performed using a wind tunnel. The rotor comprises four straight blades with a profile of NACA0018, chord length of 80.5 mm, pitch radius of R = 230 mm, and a blade width of 490 mm. The guide vane has a profile of a circular arc and a chord length of l = 87 mm. The distance between these two guide vanes w and the gap between the rotor blade and guide vane G were altered to investigate the effects of the guide vane solidity l/w and position G/R. In addition, we performed computational fluid dynamics (CFD) on exactly the same configuration as the experimental system to study the effect of the guide vane position. The experimental results indicated that the guide vane solidity l/w and position G/R suitable for the proposed turbine are obtained in the case of l/w = 1.09 and G/R = 0.11. The flow visualization was determined using CFD. Moreover, we confirmed the control of the flow separation by the setting of the guide vane.