Design and Manufacturing of Wind Turbine Blades of Low Capacity Using CAD/CAM Techniques and Composite Materials

Abstract

This paper proposes a methodology for design and manufacturing of wind turbine blades of low capacity with CAD (Computer Aided Design)/ CAM (Computer Aided Manufacturing) techniques and composite materials. The design of the blades was performed with help of specialized software, one of them developed in the author's institution (TIMEO®). The manufacturing of the blades model was executed in a machining center of three axes CNC, DYNA MYTE DM-4800. The final manufacture of composite materials was performed.The wind energy is an indirect form of the solar energy, since they are the temperature differences and the pressure-induced in the atmosphere by absorbing solar radiation, which set in motion the winds. The rotor mission in a wind turbine is transforming this kinetic energy of wind to mechanic energy. In this paper the design of the blades is based on the blade element moment theory. For the design and manufacturing CAD/CAM was developed a general methodology. In manufacturing of the blade was necessary to manufacture a false bed, which was used as a virtual axis, this is because the milling machine where this was manufactured only has three axes.The mechanical efficiency of a wind turbine depends on other factors airfoil blade, since the aerodynamic forces that occur in this provides the torque necessary for rotating the electric generator. In this sense, obtaining highly accurate airfoil geometries helps to improve the efficiency of the wind machine.Blades were manufactured of length 75.5cm, for a 600 watts wind turbine power, the design parameters were based on the environmental conditions of the coast of Michoacán, Mexico. The machining of the blades model are made from wood by mechanical milling, which is a manufacturing process for metal removal performed by the motion of a rotating cutting tool called milling cutter. The final manufacture of fiberglass performed and in which an internal structure is proposed to provide the parameters necessary rigidity and flexibility.The results obtained show that is feasible the manufacture of this type of mechanical elements through these techniques. We show that the precise control of geometry directly impacts in the aerodynamic efficiency of wind machine.