Background:
This patent is based on the wind industry technology called Diffuser Augmented
Wind Turbines (DAWTs). This technology consists of a horizontal axis wind turbine, which is
housed inside a duct with diverging section in the direction of the free air stream. In this paper, a review
of preceding patents related to this technology is carried out.
Objective:
This paper presents an innovative patent to improve the performance of horizontal axis wind
turbines. In particular, this system is aimed at improving the performance of those turbines that otherwise
might not be installed due to the low wind resource existing at certain locations.
Methods:
The most innovative elements of this patent are: (1) the semi-spherical grooves, which are
mechanized on the surface of the two diffusers in order to guarantee a more energetic boundary layer;
(2) the coaxial diffuser, which is located downwind following the first diffuser in order to increase the
suction effect on the air mass close to the inlet; (3) the coaxial rings located around the first diffuser
outlet, which are used to deflect the external airflow toward the turbine wake; and (4), the selforientating
system to orientate the system by the prevailing wind direction.
Results:
An application of the patent for increasing the power generated by a horizontal axis wind turbine
with three blades is presented. The patent is designed and its performance is evaluated by using a
Computational Fluid Dynamics code. The numerical results show that this system rises the airflow
going through the rotor of the turbine.
Conclusion:
The patented device is an original contribution aimed at enabling a more profitable installation
of wind turbines in places where the wind resource is insufficient because of the wind shear
caused both by the proximity of the earth and the obstacles on the earth surface.