Performance Research of Counter-rotating Tidal Stream Power Unit

Abstract

An experimental investigation was carried out to improve the performance of a counter-rotating type horizontal-axis tidal stream power unit. Front and rear blades were designed separately based on modified blade element momentum (BEM) theory, and their performances at different conditions of blade tip speed ratio were measured in a wind tunnel. Three different groups of blades were designed successively, and the results showed that Group3 possessed the highest power coefficient of 0.44 and was the most satisfactory model. This experiment shows that properly increasing diameter and reducing chord length will benefit the performance of the blade.