Darrieus Wind Turbines
Darrieus Wind Turbines
What is a Darrieus wind turbine - Darrieus (VAWT)
wind | educationA
Darrieus is a type of
vertical axis wind turbine (VAWT) generator. Unlike the
Savonius wind turbine, the
Darrieus is a
lift-type VAWT. Rather than collecting the wind in cups
dragging the turbine around, a Darrieus uses
lift forces generated by the wind hitting
aerofoils to create rotation.
Benefits of the Darrieus Wind Turbine
A Darrieus wind turbine can spin at many times the speed of the wind hitting it (i.e. the
tip speed ratio (TSR) is greater than 1). Hence a Darrieus wind turbine generates less torque than a Savonius but it rotates much faster. This makes Darrieus wind turbines much better suited to electricity generation rather than water pumping and similar activities. The centrifugal forces generated by a Darrieus turbine are very large and act on the turbine blades which therefore have to be very strong - however the forces on the bearings and generator are usually lower than are the case with a Savonius.
Self Starting Darrieus Wind Turbines
Darrieus wind turbines are not
self-starting. Therefore a small powered motor is required to start off the rotation, and then when it has enough speed the wind passing across the aerofoils starts to generate torque and the rotor is driven around by the wind. An alternative is shown in the illustration above. Two small
Savonius rotors are mounted on the shaft of the Darrieus turbine to start rotation. These slow down the Darrieus turbine when it gets going however they make the whole device a lot simpler and easier to maintain.
Variants of the Darrieus wind turbine are the
giromill and
cycloturbine.
Article Last Modified: 16:27, 30th Jan 2007
Recommended Related Articles
People who read this article also enjoyed the following articles:
VAWT Vertical Axis Wind TurbineUnderstand the advantages and disadvantages of VAWTs
Article Last Modified: 15:35, 30th Jan 2007windSavonius Wind TurbinesWhat is a savonius wind turbine - savonius (VAWT)
Article Last Modified: 12:31, 23rd Jul 2008wind | educationGiromill Darrieus Wind TurbinesWhat is a Giromill wind turbine - Darrieus (VAWT)
Article Last Modified: 16:27, 30th Jan 2007wind | educationBuy a VAWT Vertical Wind TurbineUnderstand the advantages and disadvantages of VAWTs
Article Last Modified: 09:06, 10th Jul 2008windFree VAWT Wind Turbine PlansMake your own 250 Watt vertical axis wind turbine (VAWT)
Article Last Modified: 09:31, 28th Dec 2006wind | educationBuild a Savonius Wind TurbineFind out how to build a simple DIY Savonius type VAWT
Article Last Modified: 12:31, 23rd Jul 2008windDIY 2kW Wind TurbineRead about a home built 2kW wind turbine constructed from scrap
Article Last Modified: 08:46, 4th Oct 2007wind | recyclingPVC Wind Turbine BladesLearn how to make your own PVC wind turbine blades
Article Last Modified: 15:16, 19th Aug 2008windPermanent Magnet GeneratorBuild a wind or water power system with around a PM Generator
Article Last Modified: 11:44, 21st Jul 2008wind | hydroHow I Built A Wind TurbineRead how a wind turbine was built for under US$150
Article Last Modified: 15:16, 19th Aug 2008wind | education
|
|
