Ducted wind turbine and support platform

Abstract

A wind-energy-power-generating device is disclosed for flotation on a body of water. The device includes a turbine assembly having rotor blades rotating about a rotation axis for harnessing kinetic energy from an airflow. The device includes a cowl at least partially surrounding said turbine assembly and defining an airflow passageway between a cowl inlet and outlet, having an inlet and outlet axis, respectively. The inlet and outlet axis intersect at a redirect angle. The device includes a base platform adapted to support the turbine assembly and cowl on the water. The cowl is rotatably mounted on the base platform such that it is rotatable around the turbine assembly to self-align with a wind direction. Stabilising arms extend from the base platform and are spaced circumferentially around a platform axis, to stabilise it on the water. A wind-energy-power-generating device secured to the ground or other fixed non-floating structure is also described.

We claim: 
     
         1 . A wind energy power generating device for securing to the ground or other fixed and non-floating structure, comprising:
 a turbine assembly including a plurality of rotor blades rotating about a rotation axis for harnessing kinetic energy from an airflow;   a cowl at least partially surrounding said turbine assembly and defining an airflow passageway between a cowl inlet, having an inlet axis, and a cowl outlet, having an outlet axis; and   a base platform adapted to support the turbine assembly and the cowl;   wherein the cowl is rotatably mounted on the base platform such that it is rotatable around the turbine assembly to self-align with the prevailing wind direction; and   wherein the inlet axis and the outlet axis intersect with one another at a redirect angle α.   
     
     
         2 . A wind energy power generating device according to  claim 1 , wherein the redirect angle α is between 90 and 170 degrees. 
     
     
         3 . A wind energy power generating device according to  claim 1 , wherein the plurality of turbine rotor blades are respectively assembled on sets of coaxial contra-rotating hubs such that a primary set of rotor blades rotates around a rotational axis in one direction and a secondary set of rotor blades rotates around said rotational axis in an opposite direction. 
     
     
         4 . A wind energy power generating device according to  claim 1 , wherein the rotation axis of said plurality of rotor blades extends through the base platform.  5 , A wind energy power generating device according to  claim 1 , wherein the internal surface of the cowl comprises horizontally arranged air flow guide vanes and a central vertically arranged air flow baffle. 
     
     
         6 . A wind energy power generating device according to  claim 1 , wherein the inner surface of the cowl is aerodynamically optimised to facilitate smooth flow of air flow therethrough with minimal energy losses. 
     
     
         7 . A wind energy power generating device according to  claim 1 , wherein the outer surface of the cowl is aerodynamically optimised to minimise structural loads and aerodynamic turbulence on the turbine and base platform. 
     
     
         8 . A wind energy power generating device according to  claim 1 , wherein the wind turbine arrangement is provided with a vertical stabiliser tail, either integrated with or separated from yet connected to, the ducted wind turbine in order to facilitate said weathervane movement. 
     
     
         9 . A wind energy power generating device according to  claim 8 , wherein the orientation of the cowl relative to the prevailing wind direction is controlled actively using a forward-looking sensing system, wherein sensing data is processed by on board or remote computer control systems which are configured to send control responses to electro-mechanical, pneumatic, magnetic and/or hydraulic actuators in order to either directly drive the wind turbine cowl into the wind or cause the components of the tail to deflect and therefore cause the cowl to rotate into the wind. 
     
     
         10 . A wind energy power generating device according to  claim 8 , wherein the tail comprises a corresponding rudder control surface, a horizontal stabiliser and corresponding elevator control surfaces and/or trim-tabs.