HomeDLSU Engineering Journalvol. 18 no. 1 (2006)

Design for Variable-Geometry Rotor of Vertical-Axis Wind Turbine Using CATIA Software

Nilo T. Bugtai | E A. Jungao

Discipline: Engineering, Technology



A ten-year plan of Philippine Energy which started in 1999 projected a wind energy contribution of 410 mega watts. The action is a part of its commitment to United Nations Framework Convention on Climate Change and is also to utilize the country's wind resource potential. However, the country is situated in a typhoon-belt Wind gustover250km/h during typhoon is one of the key problems that may hinder the wind turbine development in the country. ln the search for an alternative solution, a variable-geometry vertical axis wind turbine rotor (£0.6meter) as a test model with straight and symmetrical airfoil blades was designed. The rotor was so designed that the blades can be reefed to reduce the size of its projected area to limit both power and blade loads by self-acting control. The reduction in load was estimated based on blade element-theory; and used in the calculation of stress reduction using CATIA Version 5 design software. In the experiment, the test model was subjected to air velocities generated by industrial fans. Rotor torques for corresponding rotational speeds were calculated by inertia-acceleration method. An omni-directional cup anemometer and a non contact speed meter were used in wind speed and rotor's rotational speed measurements, respectively. A maximum power of 2.5watts (l.4%Cp) was generated by the rotor at 10.7 m/s free-air velocity and at 70 rotor rpm with blades not reefed. At the maximum reef of 60° (from vertical position) with a relative rotor area of 41 %, the torque load reduces up to 86%. The data can be used as a guide in the design of a£3-meter prototype rotor