TRAILING EDGE AIR DUCT OF A WIND TURBINE ROTOR BLADE
A rotor blade of a wind turbine, wherein the rotor blade) includes a suction side, a pressure side, a trailing edge section with a trailing edge, and a leading edge section with a leading edge is provided. The rotor blade furthermore includes an air duct at the trailing edge section which provides a flow path from the pressure side to the suction side. The air duct includes an inlet portion) and an outlet portion, and the air duct is configured such that at least a portion of the airflow from the leading edge section to the trailing edge section is permanently guided through the air duct.
1 . A rotor blade of a wind turbine, comprising:
a suction side;
a pressure side;
a trailing edge section with a trailing edge;
a leading edge section with a leading edge; and
an air duct at the trailing edge section which provides a flow path from the pressure side to the suction side;
wherein the air duct comprises an inlet portion and an outlet portion, the air duct being configured such that at least a portion of an airflow from the leading edge section to the trailing edge section is permanently guided through the air duct.
2 . The rotor blade according to claim 1 , wherein a configuration of the air duct is independent of an operational mode of the wind turbine.
3 . The rotor blade according to claim 1 , wherein the air duct is a part of a flap which is composed as a separate piece with regard to the remaining trailing edge section of the rotor blade.
4 . The rotor blade according to claim 3 , wherein the flap comprises an attachment portion for attaching the flap to the remaining trailing edge section of the rotor blade.
5 . The rotor blade according to claim 4 , wherein the flap comprises a pressure side portion, the pressure side portion at least partially substitutes and extends the pressure side of the remaining trailing edge section of the rotor blade, and an angle between the attachment portion and the pressure side portion is between one degrees and twenty-five degrees.
6 . The rotor blade according to claim 3 , wherein the flap is attached to the remaining trailing edge section of the rotor blade by an adhesive bond.
7 . The rotor blade according to claim 1 , wherein a spanwise extension of the air duct is between 1% and 200% of a chord length.
8 . The rotor blade according to claim 1 , wherein a chordwise extension of the air duct between an upstream end of the inlet portion and a downstream end of the outlet portion is between 2% and 50% of the chord length.
9 . The rotor blade according to claim 1 , wherein a minimum height of the air duct in a direction perpendicular to a span and perpendicular to a chord is between 0.1% and 10% of the chord length.
10 . The rotor blade according to claim 1 , wherein an upstream end of the outlet portion is arranged between 75% and 100% of a chord length.
11 . The rotor blade according to claim 1 , wherein a spanwise extension of the inlet portion of the air duct increases from an upstream end of the inlet portion towards the trailing edge of the rotor blade.
12 . The rotor blade according to claim 1 , wherein a spanwise extension of the entire outlet portion of the air duct is substantially constant.
13 . The rotor blade according to claim 1 , wherein the air duct is arranged at a spanwise position of the rotor blade between 20% and 80% of a total length of the rotor blade.
14 . The rotor blade according to claim 5 , wherein the angle between the attachment portion and the pressure side portion is between five degrees and fifteen degrees.
15 . The rotor blade according to claim 7 , wherein the spanwise extension of the air duct is between 2% and 50% of the chord length.
16 . The rotor blade according to claim 8 , wherein the chordwise extension of the air duct between an upstream end of the inlet portion and a downstream end of the outlet portion is between 5% and 20% of the chord length.
17 . The rotor blade according to claim 9 , wherein the minimum height of the air duct in the direction perpendicular to the span and perpendicular to the chord is between 0.5% and 5% of the chord length.
18 . The rotor blade according to claim 10 , wherein the upstream end of the outlet portion is arranged between 85% and 100% of the chord length.
19 . The rotor blade according to claim 13 , wherein the air duct is arranged at the spanwise position of the rotor blade between 30% and 70% of the total length of the rotor blade.