Wind turbine blade and wind turbine with a plurality of add-on elements
A wind turbine blade includes a plurality of add-on elements, which are arranged on an outer surface of the blade, wherein the plurality of add-on elements includes at least one flexible add-on element and at least one stiff add-on element of the same add-on element type, wherein the flexible add-on element is made at least predominantly of an elastic material and the stiff add-on element are made at least predominantly of a stiff material, which is stiffer than the elastic material, wherein the flexible add-on element and the stiff add-on element are arranged offset in span-wise direction and/or in chord-wise direction of the blade.
1. A wind turbine blade comprising a plurality of add-on elements, which are arranged on an outer surface of the blade, wherein the plurality of add-on elements comprises at least one flexible add-on element and at least one stiff add-on element of the same add-on element type, wherein the at least one flexible add-on element consists at least predominantly of an elastic material and the at least one stiff add-on element consists at least predominantly of a stiff material, which is stiffer than the elastic material, wherein the at least one flexible add-on element and the at least one stiff add-on element are arranged offset in a span-wise direction and/or in a chord-wise direction of the blade,
wherein one or more flexible add-on elements of the at least one flexible add-on element are arranged in a surface portion of the blade, which has a span-wise length between 1 m and 5 m and extends in the chord-wise direction at least partly around an outer circumference of the blade, wherein a center of the surface portion in the span-wise direction is distanced from a root-side end of the blade between 33% and 50% of the span-wise length of the blade, wherein the at least one stiff add-on element is arranged outside of the surface portion.
2. The wind turbine blade according to claim 1 , wherein the blade comprises at least one blade handling zone provided as contact area for a blade lifting means and/or a blade storage means, wherein the at least one blade handling zone extends within a span-wise segment of the outer surface in the chord-wise direction at least partially around the outer circumference of the blade, wherein the at least one flexible add-on element is arranged within the at least one blade handling zone and the at least one stiff add-on element is arranged outside of the at least one blade handling zone.
3. The wind turbine blade according to claim 1 , wherein another one or more flexible add-on elements of the at least one flexible add-on element are arranged in a pair of surface portions, which each have a span-wise length between 1 m and 5 m and which each extend in the chord-wise direction at least partly around the outer circumference of the blade, wherein the surface portions are arranged offset in the span-wise direction around the center of gravity of the blade, wherein the at least one stiff add-on element is arranged outside of the surface portions.
4. The wind turbine blade according to claim 3 , wherein the surface portions of the pair of surface portions are arranged each in a span-wise distance between 10 m and 15 m to the center of gravity.
5. The wind turbine blade according to claim 1 , wherein the blade comprises a root-side handling zone with a span-wise length between 1 m and 5 m, wherein the root-side handling zone extends in the chord-wise direction around the entire circumference of the blade, wherein the add-on elements are arranged outside of the root-side handling zone.
6. The wind turbine blade according to claim 1 , wherein the add-on elements of the same add-on element type are vortex generators, trailing edge profiles, blade surface flaps, or sensor means.
7. The wind turbine blade according to claim 1 , wherein the elastic material of the at least one flexible add-on element is an elastomeric material.
8. The wind turbine blade according to claim 7 , wherein the elastomeric material has a Shore hardness between A30 and A95.
9. The wind turbine blade according to claim 1 , wherein the stiff material of the at least one stiff add-on element is a polymer material.
10. The wind turbine blade according to claim 9 , wherein the stiff material has a Young's modulus between 1000 MPa and 4000 MPa.
11. A wind turbine comprising at least one wind turbine blade according to claim 1 .
12. The wind turbine blade according to claim 1 , wherein the stiff material of the at least one stiff add-on element is acrylonitrile styrene acrylate.
13. A wind turbine blade comprising a plurality of add-on elements, which are arranged on an outer surface of the blade, wherein the plurality of add-on elements comprises at least one flexible add-on element and at least one stiff add-on element of the same add-on element type, wherein the at least one flexible add-on element consists at least predominantly of an elastic material and the at least one stiff add-on element consists at least predominantly of a stiff material, which is stiffer than the elastic material, wherein the at least one flexible add-on element and the at least one stiff add-on element are arranged offset in a span-wise direction and/or in a chord-wise direction of the blade, wherein one or more flexible add-on elements of the at least one flexible add-on element are arranged in a pair of surface portions, which each have a span-wise length between 1 m and 5 m and which each extend in the chord-wise direction at least partly around the outer circumference of the blade, wherein the surface portions are arranged offset in the span-wise direction around the center of gravity of the blade, wherein the at least one stiff add-on element is arranged outside of the surface portions.
14. The wind turbine blade according to claim 13 , wherein the blade comprises at least one blade handling zone provided as contact area for a blade lifting means and/or a blade storage means, wherein the at least one blade handling zone extends within a span-wise segment of the outer surface in the chord-wise direction at least partially around the outer circumference of the blade, wherein the at least one flexible add-on element is arranged within the at least one blade handling zone and the at least one stiff add-on element is arranged outside of the at least one blade handling zone.
15. The wind turbine blade according to claim 13 , wherein another one or more flexible add-on elements of the at least one flexible add-on element are arranged in a surface portion of the blade, which has a span-wise length and extends in the chord-wise direction at least partly around the outer circumference of the blade, wherein a center of the surface portion in the span-wise direction is distanced from a root-side end of the blade between 33% and 50% of the span-wise length of the blade, wherein the at least one stiff add-on element is arranged outside of the surface portion.
16. The wind turbine blade according to claim 13 , wherein the surface portions of the pair of surface portions are arranged each in a span-wise distance between 10 m and 15 m to the center of gravity.
17. The wind turbine blade according to claim 13 , wherein the blade comprises a root-side handling zone with a span-wise length between 1 m and 5 m, wherein the root-side handling zone extends in the chord-wise direction around the entire circumference of the blade, wherein the add-on elements are arranged outside of the root-side handling zone.
18. The wind turbine blade according to claim 13 , wherein the add-on elements of the same add-on element type are vortex generators, trailing edge profiles, blade surface flaps, or sensor means.
19. The wind turbine blade according to claim 13 , wherein the elastic material of the at least one flexible add-on element is an elastomeric material and/or wherein the stiff material of the at least one stiff add-on element is a polymer material.
20. A wind turbine comprising at least one wind turbine blade according to claim 13 .