The combed-teeth structure of Siemens’ new low-noise DinoTail aerodynamic blade add-on mimics an owl wing’s trailing edge fringe. For comparison, an un-combed blade is shown on the left.
By Editors of Power Engineering
Following years of research and development, Siemens announced a breakthrough in low-noise wind turbine blade design. The new DinoTail technology is an aeroacoustic noise augmentation tool patterned after the trailing fringe of an owl’s wing during flight. It can be added to existing blades.
Silent operation of onshore wind projects is important for facilities located near populations that might be disturbed by noisier turbine blades. To combat this problem, Siemens patterned new technology after the wings of owls, who are silent hunters that fly without noise to better hunt their prey. A serrated, fringed structure at the back edge of the wing, along with small combs at the front edge of the wing, is believed to mitigate the noise of airflow via the creation of small vortices.
In addition to vortex generators on the blade surface, Siemens now equips trailing edges with a combination of serrations and combs. These combed teeth create fine vortices at the point where the fast air stream from above the blade meets the slower flow from below. As a result, the aerodynamic noise from the trailing edge of the blade is reduced significantly.
“In our wind tunnel measurements and field tests, the combed teeth showed a substantial reduction in wind turbine noise at all wind speeds,” said Stefan Oerlemans, Key Expert, Aeroacoustics, at the technology department of Siemens Wind Power.
The new combed-teeth blade add-on will largely replace Siemens’ first generation DinoTail for onshore wind turbines. Serial manufacturing will begin soon as part of the low-noise equipment of the new Siemens wind turbine SWT-3.3-130LN. The new DinoTail technology will also be applied to subsequent turbine models.
The new design does not compromise blade performance or annual energy production, says Siemens.