Mountable wing tip device for mounting on a rotor blade of a wind turbine arrangement

1. A mountable wing tip device for mounting on a rotor blade of a wind turbine, the mountable wing tip device comprising:

a) a forward extremity and at least three rearward extremities including a first rearward extremity, a second rearward extremity, and a third rearward extremity,

b) wherein the forward extremity and two of the first, second and third rearward extremities are triangularly arranged,

c) a leading edge region extending between the forward extremity and two of the first, second and third rearward extremities, and

d) a trailing edge region extending between the first, second, and third rearward extremities, and

e) a root region at which the wing tip device is mountable on an end of the rotor blade,

f) wherein the root region is positioned between the leading edge region and the trailing edge region

wherein the root region comprises: a rectangular shaped recess, and two holes extending through the wing tip device and opening into the recess such that the two holes are each configured to receive a screw mounted to the rotor blade.

2. The mountable wing tip device according to claim 1 , wherein the leading edge region comprises a V-shape, and a length between one of the first and second rearward extremities and the forward extremity differs from a length between the forward extremity and the third rearward extremity.

3. The mountable wing tip device according to claim 1 , wherein the leading edge region comprises an arced tip portion at the forward extremity.

4. The mountable wing tip device according to claim 1 , wherein a profile of the wing tip device defines an airfoil extending from the forward extremity to the rearward extremities and comprising a maximum thickness disposed between the forward extremity and the first, second, and third rearward extremities.

5. The mountable wing tip device according to claim 4 , wherein the maximum thickness of the airfoil is closer to the forward extremity than to any of the first, second, and third rearward extremities.

6. The mountable wing tip device according to claim 4 , wherein the forward extremity and the third rearward extremity of the wing tip device are arranged on a connection line, and wherein the airfoil comprises a minimum thickness between the leading edge region and the connection line.

7. The mountable wing tip device according to claim 1 , wherein a profile of the wing tip device defines an airfoil extending from the forward extremity toward the rearward extremities and comprising a minimum thickness disposed between two adjacent rearward extremities.

8. The mountable wing tip device according to claim 1 , wherein the trailing edge region comprises a ‘W’-shape having the first, second, and third rearward extremities and two curved rounds such that each curved round is disposed between adjacent rearward extremities and projects toward the forward extremity.

9. The mountable wing tip device according to claim 1 , wherein the forward extremity and third rearward extremity are arranged in a main plane P, and the first and second rearward extremities are inclined away from the main plane P, such that the first and second rearward extremities are not disposed in the main plane P.

10. The mountable wing tip device according to claim 9 , wherein the first and second rearward extremities disposed at opposing ends of the trailing edge are inclined in opposite directions with respect to the main plane P.

11. The mountable wing tip device according to claim 1 , wherein at least one of the first and second rearward extremities is inclined with respect to a plane spanned by the other one of the first and second rearward extremities, the third rearward extremity, and the forward extremity.

12. A wind turbine arrangement comprising:

a rotor hub being coupled with at least one rotor blade comprising a suction side and a pressure side;

a generator having a rotor and a stator, the rotor having mounted thereupon the rotor hub, and being rotatably supported on the stator; and

a blade tip assembly comprising a mountable wing tip device according to claim 1 , wherein at least one of the first and second rearward extremities is inclined with respect to a plane spanned by the other one of the first and second rearward extremities, the third rearward extremity, and the forward extremity,

wherein the mountable wing tip device is mounted to an end of a respective rotor blade, such that one of the rearward extremities inclines towards the suction side of the respective rotor blade and another one of the rearward extremities inclines towards the pressure side of the respective rotor blade.

13. The wind turbine arrangement according to claim 12 , wherein the first rearward extremity extends toward the suction side of the respective rotor blade and the second rearward extremity extends toward the pressure side of the respective rotor blade.

14. The wind turbine arrangement according to claim 12 , wherein a profile of the rotor blade defines an airfoil comprising a maximum thickness that is disposed between the forward extremity and a respective rearward extremity of the mountable wing tip device.

15. The wind turbine arrangement according to claim 14 , wherein the maximum thickness of the airfoil of the rotor blade is located closer to the forward extremity than any of the first, second and third rearward extremities.

16. A blade tip assembly comprising a blade portion and a mountable wing tip device for mounting on a rotor blade of a wind turbine, the mountable wing tip device comprising:

a) a forward extremity and at least three rearward extremities including a first rearward extremity, a second rearward extremity, and a third rearward extremity,

b) wherein the forward extremity and two of the first, second and third rearward extremities are triangularly arranged,

c) a leading edge region extending between the forward extremity and two of the first, second and third rearward extremities, and

d) a trailing edge region extending between the first, second, and third rearward extremities, and

e) a root region at which the wing tip device is mountable on an end of the rotor blade,

f) wherein the root region is positioned between the leading edge region and the trailing edge region

wherein the blade portion comprises a blade connecting portion which connects the blade portion to the rotor blade and a wing tip connecting portion which connects the blade portion to the mountable wing tip device.

17. The blade tip assembly according to claim 16 , wherein the blade connecting portion comprises a rough surface for facilitating alignment of the rotor blade of the wind turbine with the blade connecting portion and the mountable wing tip device.

18. The blade tip assembly according to claim 17 , wherein the rough surface comprises grooves.

19. The blade tip assembly according to claim 16 , wherein the blade connecting portion comprises two ends, one end being mounted at the root region of the mountable wing tip device and the other end being mountable at the rotor blade.

20. The blade tip assembly according to claim 16 , wherein the blade connecting portion comprises at least one extension part extending between the wing tip device and the rotor blade, wherein the shape of the extension part corresponds to the shape of the rotor blade.

21. The blade tip assembly according to claim 16 , wherein the blade connecting portion extends through the mountable wing tip device and includes screws for clamping the mountable wing tip device towards an end of the rotor blade of the wind turbine when mounted.