A rotor blade, noise reduction means for a rotor blade, and method for reducing noise for a rotor blade

The wind turbine rotor blade of any of previous claim, wherein the first and second pressure communication channels each have a generally continuous inner surface connected to the pressure side surface and/or the suction-side surface.

The wind turbine rotor blade of any of previous claim, wherein the plurality of pressure communication channels define a pressure communication channel number density that is increasing in the direction from the leading-edge section to the trailing-edge section.

The wind turbine rotor blade of any preceding claim, wherein the wind turbine rotor blade further comprises a camber line connecting the leading-edge section and the trailing-edge section and lying half-way between the pressure-side surface and the suction-side surface, wherein the camber line of the aerodynamic structure is tilted toward the suction-side surface with respect to a camber line of the rest of the wind turbine rotor blade, preferably the camber line of the aerodynamic structure is tilted toward the suction-side surface with an angle of at least 1°, preferably between 1.5-10°, more preferably between 2-5°.

The wind turbine rotor blade of any preceding claim, wherein the plurality of pressure communication channels comprises at least three different sizes of surface areas on the pressure-side surface and/or on the suction-side surface.

The wind turbine rotor blade of any preceding claim, wherein at least one of the first and second pressure communication channels comprises at least one airflow blocking means configured between the suction-side surface and the pressure-side surface, wherein the at least one airflow blocking means is acoustically permeable, preferably the blocking means is located at the third minimal surface area.

The wind turbine rotor blade of any preceding claim, wherein the aerodynamic structure is an add-on attached to the trailing-edge section of the wind turbine rotor blade, or wherein the aerodynamic structure is integrally formed as the trailing-edge section of the wind turbine rotor blade.

The wind turbine rotor blade of any preceding claim, wherein the aerodynamic structure is forming the trailing-edge section and connected to rest of the wind turbine rotor blade using any or any combination of following means:

• (i) a butt joint, (ii) a socket at the suction-side surface, (iii) a socket at the pressure-side surface, (iv) a hinge, (v) a flexible connecting member, or (vi) flexible connecting sheet elements.

The wind turbine rotor blade of any preceding claim, wherein the plurality of pressure communication channels is irregularly distributed with at least three different spacings, preferably with at least four different spacings, more preferably with at least five different spacings, even more preferably with at least six different spacings.

The wind turbine rotor blade of any preceding claim, wherein the aerodynamic structure further comprises a serration at the trailing-edge.

A method of producing the wind turbine rotor blade of any preceding claim for noise reduction.