عنوان مقاله [English]
The aim of the present paper is fabrication and testing an axial wind turbine with power-coefficient greater than 55 percent. Since this power-coefficient is the highest value among the most recent fabricated axial turbines. The present study has led to manufacturing new design of a small wind turbine that has shown power-coefficient of 68 to 80 percent in experimental measurements. Measuring power-coefficient of two-propeller rotor of the wind turbine is in accordance with double-actuator-disc theory, which has proved achievement to power-coefficient of 64 percent. The rotor of the wind turbine consists of an axial three-blade propeller and an optimized six-blade combined-propeller. The parts of the wind turbine have been manufactured with three-dimensional print technology. A large axial fan has been installed horizontally to produce wind flow. A miniature mechanical brake has been installed on the rotor’s axis and it is adjustable for generating constant braking torque. The rotor’s drag force has been measured with the S-type load-cell that was accommodated in an aerodynamic structure. The small wind turbine has preserved its optimum power-coefficient in the low speed wind flow (in the range 1 to 3 m/sec). Experiment has been accomplished for the rotor of turbine and for the wind turbine having walls and supporting arms and nearly the same results has been achieved.