Study of the Shape of a Vertical Axis Micro Wind Turbine With Wooden Blades

The article illustrates the fluid-dynamic and mechanical analysis of some forms of small-power vertical axis wind turbines, resistant type, whose blades are made of wood and easily workable in a joinery. In particular, a classical-shaped Savonius, a modified two blades Savonius, a three-bladed Savonius and, again, a rotor with three straight blades having a crescent-moon section, were studied. A result of the study, worthy of note, concerns the possibility of greatly reducing the mechanical stresses on the support relatively to the rotor having the last shape. This is very important for its installation near inhabited buildings or even integrated into roofs. Furthermore, the crescent-moon section prototype is able to provide 1 kW power at the nominal wind condition of 12.5 m/s and an annual energy production of 1200-1500 kWh/year, considering a typical urbane site having an average wind speed between 4.5 and 5 m/s.