Dinosaur features applied to wind turbine blades

["Richard W. Travsky" <rtravsky@uwyo.edu>]

http://www.newscientist.com/article/mg21528825.500-dinosaurinspired-upgrades-add-bite-to-wind-turbines.html

WHEN it comes to wind turbines, every bit of extra power counts. Replacing 
the machines entirely can be a costly business, however.

So Siemens has unveiled three designs for enhancing the aerodynamics of 
turbine blades. The first, DinoTails, resembles the back plates of a 
stegosaur and increases the area of a blade, adding lift and so power. It 
also makes them quieter. When air flows from above and below the trailing 
edge of a turbine blade meet, they create turbulence, which can increase 
drag and make it noisy. The DinoTails' serrated edge breaks up that flow, 
reducing the turbulence.

A snow-shovel-shaped device called DinoShells extends the blade shape down 
to where it joins the main shaft, making the turbine more efficient. The 
third attachment is called a vortex generator, featuring small fins that 
force the air to stay in contact with the top of the blade for longer, 
increasing lift. Siemens says combining the three could increase the 
energy output of an older turbine by up to 1.5 per cent. That may not 
sound like a lot, but the Altamont Pass Wind Farm in California - one of 
the world's biggest - produces 125 megawatts on average. A 1.5 per cent 
increase there would meet the energy needs of an extra 2500 households.
...