quiet revolution

egg beater wind turbines

"Eggbeater" turbines. They have good efficiency, but produce large torque ripple and cyclic stress on the tower, which contributes to poor reliability. Also, they generally require some external power source, or an additional Savonius rotor, to start turning, because the starting torque is very low. The torque ripple is reduced by using three or more blades which results in a higher solidity for the rotor. Solidity is measured by blade area over the rotor area. Newer Darrieus type turbines are not held up by guy-wires but have an external superstructure connected to the top bearing.

wind turbine

A wind turbine is a rotating machine which converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is then converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.

Bluenergy Solar-Wind-Turbine

Bluenergy Solar-Wind-Turbine

"BSWT is a vertical wind turbine based on sailing engineering. The wind rotor is rotated by two spiral-formed vanes. For best performance, these vanes are covered in solar cells, so that sun and wind produce electricity as one element. The BSWT installation costs relatively little, produces no noise or significant shadowing, can be easily maintained from ground level, and is an attractive addition to any home." - http://www.bluenergy-ag.net/English/products_wind.html

Wind Dam

The massive growth in 2008 swelled the nation’s total wind power generating capacity by 50% and channeled an investment of some $17 billion into the economy, positioning wind power as one of the leading sources of new power generation in the country today along with natural gas, AWEA added. However, at year’s end financing for new projects and orders for turbine components slowed to a trickle as layoffs began to hit the wind turbine manufacturing sector.
“Our numbers are both exciting and sobering,” said AWEA CEO Denise Bode. “The U.S. wind energy industry’s performance in 2008 confirms that wind is an economic and job creation dynamo, ready to deliver on the President’s call to double renewable energy production in three years US - Wind Energy Generating Capacity Grows by 50%
in 2008 »
wind-energy1
Posted on January 28, 2009 1 Comment »

The Java Virtual Wind Tunnel

A Two Dimensional Computational Fluid Dynamics SimulationThe Java Virtual Wind Tunnel is an applet which uses computational fluid dynamics (CFD) methods to simulate the flow of air over a two dimensional object. The applet is not just a movie projector; it actually solves the equations of motion (the Euler equations) in real time. So the results on the screen are the real thing, not an animation. And in a virtual wind tunnel, adding instruments costs nothing. In fact, the simulation provides more information about the flow than you could easily access in any real wind tunnel.
The Java Virtual Wind Tunnel is just a prototype. But it shows how Java can be used to build educational tools for undergraduate and graduate fluids mechanics courses. At the undergraduate level, the simulations might help students visualize and understand 2-D fluid flow. At the graduate level, it might help students understand the power and limitations of computational fluid dynamics.
The prototype Java Virtual Wind Tunnel is running at the top of this page. This demonstration shows the flow of air through a channel with a "bump" in one of the walls. If you let the applet run, a shock wave will appear above the bump where the flow jumps from supersonic to subsonic speeds. Moving the sliders will change the flow conditions and cause the shock to appear and disappear. - http://raphael.mit.edu/Java/ - David Oh / Computational Aerospace Sciences Laboratory, MIT / bamf@attbi.com