Risø DTU and Vestas are planning to develop smart wind turbine blades. The wind turbine blades are able to adjust according to the wind. The idea has already been tested in a wind tunnel. The trailing edge of the blade is transformed into a movable flap as it is known from airplanes. The Danish National Advanced Technology Foundation granted 15 million DKK for the project yesterday. The movable flaps reduce the load on blades and turbine structure and at the same time make the wind turbine more efficient. Consequently this type of wind turbine blade will have major significance for the economy of wind turbines.
Nature figured out this principle already when bird life emerged. When a bird of prey is “standing” in the air, chasing mice, it adjusts its wings in a very advanced way causing its eyes to remain completely still. This principle is to be copied in order to develop a new wind turbine blade.
The principle has proved effective in a wind tunnel. Now Vestas and Risø DTU are going to spend the 15 million DKK to show that the idea can be applied on large Vestas wind turbines. More detailed aerodynamic calculations will have to be made and the control of the blade flap will have to be developed.
The system works through a sensor that measures the wind about to hit the wind turbine. Then a computer figures out how the flap should be arranged and sends out a signal to the flap.
To begin with, the system will be tested on a wind turbine at Risø so that the scientists learn to handle the control system. The wind sensor is probably going to be a Pitot tube also used to measure the speed of airplanes. The signals from the sensor will be sent to a computer in the turbine house and this will probably happen through a wireless connection. The control signal of the computer will then be transferred to the flap without the use of wire. The flap may be produced from piezoelectric crystals that bend when power is added. It may also be a hollow rubber rear edge that changes shape when filled with a hydraulic fluid.
The project runs for 3 ½ years. During the first six months PhD students will be hired. They are to contribute to research. Vestas is planning to appoint 2-3 PhD students, Risø is going to appoint an equivalent number and 2 are going to be appointed at DTU’s Department of Mechanical Engineering (MEK). Scientists expect that 10 years will pass before the new blades are common on large Vestas wind turbines. See the press release from The Danish National Advanced Technology Foundation here.
Further information: Senior Scientist Thomas Buhl, T 4677 5467, thomas.buhl@risoe.dk
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