Vortex generator for fastening to a wind turbine rotor blade

1. A vortex generator defining a longitudinal direction in which the vortex generator receives an incident flow of air, the vortex generator comprising:

two fins each arranged at an angle α in relation to the longitudinal direction;

a base interconnecting the two fins;

said base having a width (B) extending from one of the two fins to the other one of the two fins;

said base having a forward edge facing into said incident flow and a rearward edge facing away from said incident flow;

said forward and rearward edges delimiting said base along said width (B) between said fins;

said base and each of said fins defining respective interfaces whereat said fins transition into said base;

said two fins each having a first longitudinal portion having a first lower edge at a corresponding one of said interfaces;

said two fins further each having a second longitudinal portion cantilevered from said first longitudinal portion and arranged to project outwardly from said base away from said forward edge thereof; and,

each of said second longitudinal portions having a lower edge at an elevation at or lower than the elevation of the interface corresponding thereto.

2. The vortex generator of claim 1 , wherein said base has a fastening face for bonding to a surface of a wind turbine rotor blade.

3. The vortex generator of claim 2 , wherein said fastening face has a curvature in the longitudinal direction.

4. The vortex generator of claim 1 , wherein:

said two fins each further have a third longitudinal portion cantilevered from said first longitudinal portion and arranged to project outwardly from said base away from said rearward edge thereof; and,

each of said third longitudinal portions have a lower edge at an elevation at or below the elevation of the interface corresponding thereto.

5. The vortex generator of claim 4 , wherein:

said second longitudinal portion is arranged in a plane and said lower edge thereof projects downward and extends outward beyond said base; and,

said third longitudinal portion is arranged in a plane and said lower edge thereof projects downward and extends outward beyond the base.

6. The vortex generator of claim 4 , wherein said second longitudinal portion is arranged in a plane and said lower edge thereof projects downward and extends outwardly beyond said base.

7. The vortex generator of claim 4 , wherein said third longitudinal portion is arranged in a plane and said lower edge thereof projects downward and extends outwardly beyond the base.

8. The vortex generator of claim 4 , wherein:

at least one of said lower edge of said second longitudinal portion and said lower edge of said third longitudinal portion is curved.

9. The vortex generator of claim 4 , wherein:

at least one of said lower edge of said second longitudinal portion and said lower edge of said third longitudinal portion is arranged at an angle in relation to said lower edge of said first longitudinal portion.

10. The vortex generator of claim 4 , wherein at least one of said second longitudinal portion and said third longitudinal portion has an angled peripheral portion at the lower edge thereof.

11. The vortex generator of claim 1 , wherein the vortex generator is made by stamping out a flat material, and then bending said two fins at an angle relative to said base.

12. The vortex generator of claim 2 further comprising a double-sided adhesive tape stuck onto said fastening face.

13. The vortex generator of claim 12 , wherein:

said fastening face has a fastening face width; and,

said double-sided adhesive tape extends, in the longitudinal direction, over an entirety of at least one of said fastening face width, said width B of said base, and said second length L 2 .

14. A wind turbine rotor blade comprising:

a rotor blade body defining a surface;

a vortex generator defining a longitudinal direction in which the vortex generator receives an incident flow of air during rotation of said rotor blade body;

said vortex generator having two fins each arranged at an angle α in relation to the longitudinal direction;

said vortex generator further having a base interconnecting the two fins;

said base having a width (B) extending from one of the two fins to the other one of the two fins;

said base having a forward edge facing into said incident flow and a rearward edge facing away from said incident flow;

said forward and rearward edges delimiting said base along said width (B) between said fins;

said base and each of said fins defining respective interfaces whereat said fins transition into said base;

said two fins each having a first longitudinal portion having a first lower edge at a corresponding one of said interfaces;

said two fins further each having a second longitudinal portion cantilevered from said first longitudinal portion and arranged to project outwardly from said base away from said forward edge thereof; and,

each of said second longitudinal portions having a lower edge at an elevation at or lower than the elevation of the interface corresponding thereto;

said vortex generator defining a fastening surface formed on said base; and,

said fastening surface being adhesively bonded to said surface of said rotor blade body.

15. The wind turbine rotor blade of claim 14 further comprising:

a seal;

said vortex generator defining edges adjoining said surface; and,

said seal being arranged between said surface and said edges of said vortex generator adjoining said surface.

16. The wind turbine rotor blade of claim 14 , wherein a plurality of identically shaped ones of said vortex generator are adhesive-bonded to said surface, at different positions of said surface at which said surface has differing curvatures.

17. A method for making a vortex generator, the vortex generator defining a longitudinal direction and including two fins each arranged at an angle c in relation to the longitudinal direction and extending over a first length L 1 in the longitudinal direction, the vortex generator further including a base interconnecting the two fins, the base having a width (B) extending from one of the two fins to the other one of the two fins, said base having a forward edge facing into said incident flow and a rearward edge facing away from said incident flow; said forward and rearward edges delimiting said base along said width (B) between said fins; said base and each of said fins defining respective interfaces whereat said fins transition into said base; said two fins each having a first longitudinal portion having a first lower edge at a corresponding one of said interfaces; said two fins further each having a second longitudinal portion cantilevered from said first longitudinal portion and arranged to project outwardly from said base away from said forward edge thereof; and, each of said second longitudinal portions having a lower edge at an elevation at or lower than the elevation of the interface corresponding thereto, the method comprising the steps of:

stamping out a flat material; and,

bending the two fins at an angle relative to the base after said stamping out the flat material.

18. A vortex generator defining a longitudinal direction in which the vortex generator receives an incident flow of air, the vortex generator comprising:

two fins each arranged at an angle α in relation to the longitudinal direction;

a base interconnecting the two fins;

said base having a width (B) extending from one of the two fins to the other one of the two fins;

said base having a forward edge facing into said incident flow and a rearward edge facing away from said incident flow;

said forward and rearward edges delimiting said base along said width (B) between said fins;

said base and each of said fins defining respective interfaces whereat said fins transition into said base;

said two fins each having a first longitudinal portion having a lower edge at a corresponding one of said interfaces;

said two fins further each having a second longitudinal portion cantilevered from said first longitudinal portion and arranged to project outwardly from said base away from said rearward edge thereof; and,

each of said second longitudinal portions having a lower edge at an elevation at or lower than the elevation of the interface corresponding thereto.