Patent ID: 8721279

Claim:
A wind turbine for extracting energy out of an airflow, the wind turbine having an axis of rotation, the wind turbine comprising: turbine blades mounted for axial rotation; a first shroud surrounding the turbine blades and defining a first axial air passage, the first shroud having an upstream opening and a downstream opening; a plurality of plates attached to the first shroud, the plates spaced radially outward from the first shroud, the plates spaced around the circumference of the first shroud and projecting beyond the downstream opening of the first shroud, the plurality of plates forming a second discontinuous shroud; the first shroud and the plurality of plates forming a second axial air passage between the first shroud and plurality of plates; the plurality of plates having gaps between adjacent plates such that air exiting the downstream opening of the first shroud and air moving through the second axial air passage are mixed and a portion of the mixed air exits through the gaps.