Experimental assessment of a 100 W prototype horizontal axis tidal turbine by towing tank tests

Abstract

In the present research, the performance of a prototype tidal turbine is evaluated via towing tank tests. The examined model is a three-bladed horizontal axis with a 1.15 m diameter. Previously, we studied the hydrodynamic behavior of this turbine and calculated the hydrodynamic coefficients using a numerical approach. Thus, this work concentrates on overwhelming the challenges, from manufacturing and assembling to data acquisition and power storage. The turbine is tested under various conditions namely: pitch angle, electrical load, carriage speed, and immersion depth to improve efficiency. Our experiment indicated the turbine performance to be the best being close to the surface of the water at different flow speeds. The optimum electrical load was found to be 20 Ω adding 16–40% to efficiency. By fixing the optimum load and tip immersion depth, the maximum efficiency of the whole rotor achieved around 0.265 at less than 0.56 m/s as towing speed while at the speed of 1.1 m/s, the maximum output power was more than 120 W having the pitch of the blades fixed at 20.4°.