Wind turbine rotor blade
Wind turbine rotor blade with a blade tip, a blade root, a leading edge, a trailing edge, a pressure side, a suction side and a cross-section, which changes from the blade tip to the blade root, the longitudinal portion being arranged between the blade root and the middle of the rotor blade, has the following: a convex pressure side portion, which extends from the leading edge up to a pressure-side inflection point, a concave pressure side addition portion, which connects with the pressure-side inflection point with a continuous curvature and extends up to the trailing edge, a convex suction side portion, which extends from the leading edge up to a suction-side kink or inflection point, and a suction side addition portion, which extends from the suction side kink or inflection point up to the trailing edge.
1. A wind turbine rotor blade comprising a blade tip ( 10 ), a blade root ( 12 ), a leading edge ( 16 ), a trailing edge ( 18 ), a pressure side ( 32 ), a suction side ( 30 ) and a cross-section, which changes from the blade tip ( 10 ) to the blade root ( 12 ), wherein the cross-section in the middle ( 14 ) of the rotor blade is formed by an aerodynamic profile and is mainly circular at the blade root ( 12 ), and wherein the cross-section in a longitudinal portion of the rotor blade, the longitudinal portion being arranged between the blade root ( 12 ) and the middle ( 14 ) of the rotor blade, comprises:
a convex pressure side portion ( 78 ), which extends from the leading edge ( 16 ) up to a pressure-side inflection point ( 80 ),
a concave pressure side addition portion ( 82 ), which connects with the pressure-side inflection point ( 80 ) with a continuous curvature and extends up to the trailing edge ( 18 ),
a convex suction side portion ( 72 ), which extends from the leading edge ( 16 ) up to a suction-side kink or inflection point ( 74 ),
a suction side addition portion ( 76 ), which extends from the suction-side kink or inflection point ( 74 ) up to the trailing edge ( 18 ), and
wherein the kink or inflection point ( 74 ) is formed such that if one follows a progression of a curve defined by the convex suction side portion ( 72 ) and the suction side addition portion ( 76 ) from the leading edge ( 16 ) up to the kink or inflection point ( 74 ), a direction of the curve changes at the kink or inflection point ( 74 ) towards an outside of the cross-section.
2. The wind turbine rotor blade according to claim 1 , wherein a distance from the pressure-side inflection point ( 80 ) to the leading edge ( 16 ), measured along the profile chord ( 84 ), is more than 60% of a profile depth.
3. The wind turbine rotor blade according to claim 1 , wherein the suction side addition portion ( 76 ) is mainly straight.
4. The wind turbine rotor blade according to claim 1 , wherein a tangent lies against the pressure side addition portion ( 82 ) at the trailing edge ( 18 ) mainly in a rotor plane when the rotor blade is arranged with reference to the rotor plane at a pitch angle optimized for partial load operation.
5. The wind turbine rotor blade according to claim 1 , wherein a tangent lies against the suction side addition portion ( 76 ) at the trailing edge ( 18 ) mainly in a rotor plane when the rotor blade is arranged with reference to the rotor plane at a pitch angle optimized for partial load operation.
6. The wind turbine rotor blade according to claim 1 , wherein an acute angle is formed between the pressure side addition portion ( 82 ) and the suction side addition portion ( 76 ) at the trailing edge ( 18 ).
7. The wind turbine rotor blade according to claim 1 , wherein the longitudinal portion begins at a distance from the blade root ( 12 ).
8. The wind turbine rotor blade according to claim 1 , wherein the longitudinal portion extends up to a distance from the blade root ( 12 ), in which the cross-section has a relative profile thickness of 60% or less.
9. The wind turbine rotor blade according to claim 1 , wherein the longitudinal portion extends up to a distance of 10% or more of a rotor blade length from the blade root ( 12 ).
10. The wind turbine rotor blade according to claim 1 , wherein the rotor blade has a constant profile depth between a first distance of 10% of a rotor blade length from the blade root ( 12 ) and a second distance of 15% of the rotor blade length from the blade root ( 12 ).
11. The wind turbine rotor blade according to claim 1 , wherein the pressure side addition portion ( 82 ) and the suction side addition portion ( 76 ) are formed by an attachment ( 20 ), which is connected with the remaining components of the rotor blade.
12. The wind turbine rotor blade according to claim 11 , wherein remaining components of the rotor blade at a longitudinal position ( 22 ) of the rotor blade have a maximum profile depth, wherein the attachment ( 20 ) begins at this longitudinal position ( 22 ) and extends from there in the direction towards the blade root ( 12 ).
13. The wind turbine rotor blade according to claim 11 , wherein remaining components of the rotor blade at a longitudinal position ( 22 ) of the rotor blade have a maximum profile depth, wherein the attachment ( 20 ) begins at a greater distance from the blade root ( 12 ) than this longitudinal position ( 22 ) and extends from there in the direction towards the blade root ( 12 ) and the profile depth of the rotor blade is enlarged by the attachment ( 20 ) above and beyond the maximum profile depth of the remaining components at least in a longitudinal portion.
14. The wind turbine rotor blade according to claim 11 , wherein the attachment ( 20 ) is subdivided into several segments.
15. The wind turbine rotor blade according to claim 11 , wherein the attachment ( 20 ) is formed by a shell-like component made of a curved jacket with even thickness.