Abstract:

In the field of renewable energy, a growing attention is given to cross flow turbine such as the Darrieus turbine. This turbine, originally used as a wind turbine, is currently used as a water turbine to extract energy from water currents, reservoirs, rivers and oceans to eventually convert into electrical energy. In the work presented in this paper a series of painstaking experiments, for different velocity of the water flow (V = 0.37 m/s to 0.73 m/s), was conducted (at the Hydro-Pneumatic Power Laboratory of Northeastern University, Boston, USA) to determine the influence of this velocity on the performance parameters of a water Darrieus turbine, such as torque, mechanical power and power coefficient. The experimental model of the water Darrieus turbine has three NACA0020 blades with a length of 0.216 m, a chord of 0.069 m and a solidity of 2. These blades are fixed at a radius of 0.104 m and an offset angle of 120°. The main finding from the results analysis, obtained with a good consistency, is the increase of the water flow velocity from 0.37 m/s to 0.73 m/s (corresponding relative Reynolds number from 3.5 104 to 2.8 105) causes an increase in torque, power and power coefficient generated by this turbine model respectively from 0.18 Nm to 0.75 Nm, from 1.66 W to 11.67 W and from 16.92 % to 31.77 %, which gives a 604 % power relative increase for a water velocity relative increase equal to 100 %.<

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