From the front, the windturbine looks something like the air intake of a jet engine. As air approaches,it first encounters a set of fixed blades, called the stator, which redirect itonto a set of movable blades--the rotor. The air turns the rotor and emerges onthe other side, moving more slowly now than the air flowing outside theturbine. The shroud is shaped so that it guides this relatively fast-movingoutside air into the area just behind the rotors. The fast-moving air speeds upthe slow-moving air, creating an area of low pressure behind the turbine bladesthat sucks more air through them. The idea for this isn't new, but pastattempts to build similar turbines were limited by the fact that the turbinehad to be very precisely aligned with the wind's direction (3-4 degrees), butaccording to FloDesign's CEO the blade designof this turbine allows it to work at angles of up to 20 degrees off the wind.Currently FloDesign just has aprototype, but a 12 foot diameter model for field testing should be ready bythe end of next year.
So where does the cost savings and increased power output come in? Because theshroud which surrounds the blades directs and speeds up the air hitting theblades, a turbine of a given size with this design can produce as much power asa traditional design with blades twice as large. This size reduction could meanthat turbines could be spaced more closely together, increasing the amount ofpower an area of land could produce.
Source: treehugger.comAdded: 22 December 2008