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6.4 Summary
A three-bladed rotor with a diameter of 2.7 m has been developed for the present wind
turbine. Achieved through an iterative process, the rotor is a design compromise, which
takes into consideration aerodynamic performance, strength and stiffness requirements,
as well as material availability and production techniques.
Aerodynamic calculations have been carried out using a rotor design tool, which has been
developed as a part of this project. Structural calculations have been performed using a
combination of numerical finite element analyses and analytical calculations.
The rotor, in combination with the generator, yields a nominal system power output of
1506 W at a wind speed of 12 m/s, which is in agreement with the requirement specifica-
tion. The annual energy production has been calculated as 935 kWh at the targeted instal-
lation site.
An alternative blade design, involving the usage of curved plates as airfoils, was proposed
as a future design option that provides a simpler, but also less efficient rotor.
ROTOR
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