Devices and methods for mitigating vibrations in wind turbines
The present disclosure relates to devices ( 300 ) for wind turbine blades ( 22 ) and methods for reducing vibrations in wind turbines ( 10 ). More particularly, the present disclosure relates to devices ( 300 ) for mitigating vortex induced vibrations and stall induced vibrations, wind turbine blades ( 22 ) comprising such devices ( 300 ), and methods for reducing wind turbine vibrations when the wind turbine ( 10 ) is parked, especially during wind turbine installation and/or maintenance. A device ( 300 ) comprises a proximal support ( 310 ) configured to be arranged around a first portion ( 221 ) of a wind turbine blade ( 22 ), a distal support ( 320 ) configured to be arranged around a second portion ( 222 ) of the wind turbine blade ( 22 ), and a barrier ( 330 ) extending between the proximal support ( 310 ) and the distal support ( 320 ). The first portion ( 221 ) of the wind turbine blade ( 22 ) is at a different longitudinal position along the blade ( 22 ) than the second portion ( 222 ). The proximal ( 310 ) and distal ( 320 ) supports are configured to provide a gap ( 350 ) between the barrier ( 330 ) and a wind turbine blade surface.
1. A device for mitigating vibrations of a parked wind turbine, comprising:
a proximal support configured to be arranged around a first portion of a wind turbine blade extending through the proximal support, a distal support configured to be arranged around a second portion of the wind turbine blade extending through the distal support, wherein the first portion of the wind turbine blade is at a different longitudinal position along the blade than the second portion;
a barrier extending between the proximal support and the distal support;
wherein the proximal and distal supports are configured to provide a gap between the barrier and a surface of the wind turbine blade such that the barrier is non-contacting relative to the wind turbine blade between the proximal and distal supports; and
the distal support comprising a shape and size to engage against the wind turbine blade at a desired position along the second portion of the wind turbine blade.
2. The device of claim 1 , wherein the device comprises a circular or elliptical cross-section.
3. The device of claim 1 , further comprising one or more additional supports between the proximal and distal supports, the additional supports spaced apart and also maintaining the barrier non-contacting relative to the wind turbine blade.
4. The device of claim 1 , wherein the barrier comprises a plurality of pores.
5. The device of claim 4 , wherein the barrier comprises a net.
6. The device of claim 4 , wherein the plurality of pores represents between 20% and 70% of an external surface of the barrier.
7. The device of claim 1 , further comprising a supporting sleeve configured to surround the wind turbine blade.
8. A device for mitigating vibrations of a parked wind turbine, comprising:
a proximal support configured to be arranged around a first portion of a wind turbine blade extending through the proximal support, a distal support configured to be arranged around a second portion of the wind turbine blade extending through the distal support, wherein the first portion of the wind turbine blade is at a different longitudinal position along the blade than the second portion;
a barrier extending between the proximal support and the distal support;
wherein the proximal and distal supports are configured to provide a gap between the barrier and a surface of the wind turbine blade such that the barrier is non-contacting relative to the wind turbine blade between the proximal and distal supports; and
wherein the device tapers from the proximal support towards the distal support.
9. A device for mitigating vibrations of a parked wind turbine, comprising:
a proximal support configured to be arranged around a first portion of a wind turbine blade, a distal support configured to be arranged around a second portion of the wind turbine blade, wherein the first portion of the wind turbine blade is at a different longitudinal position along the blade than the second portion;
a barrier extending between the proximal support and the distal support; and
wherein the proximal and distal supports are configured to provide a gap between the barrier and a surface of the wind turbine blade; and further comprising a plurality of flapping elements arranged at least partially around the barrier.
10. The device of claim 9 , wherein the flapping elements are provided in a cover configured to at least partially wrapped around the barrier.
11. A device for mitigating vibrations of a parked wind turbine, comprising:
a proximal support configured to be arranged around a first portion of a wind turbine blade, a distal support configured to be arranged around a second portion of the wind turbine blade, wherein the first portion of the wind turbine blade is at a different longitudinal position along the blade than the second portion;
a barrier extending between the proximal support and the distal support; and
wherein the proximal and distal supports are configured to provide a gap between the barrier and a surface of the wind turbine blade; and
further comprising a plurality of fins arranged at least partially around the barrier.
12. The device of claim 11 , wherein the fins are configured to follow a main direction of wind acting on the wind turbine.
13. A method for mitigating vibrations in a parked wind turbine, the method comprising:
moving a device having a barrier extending between a proximal support and a distal support around a wind turbine blade and towards a root of the blade by pulling one or more ropes attached at or near the proximal support;
securing the device on the wind turbine blade;
wherein the wind turbine blade extends through the proximal and distal supports and maintain the barrier non-contacting relative to the wind turbine blade between the proximal and distal supports; and
wherein the device is pulled by the ropes until the distal support engages against the wind turbine blade at a desired position along the wind turbine blade.
14. The method of claim 13 , further comprising lowering the one or more ropes from a hub or a nacelle and attaching the ropes at or near the proximal support.