# US 2024/0200530 A1 · Rotor blade of a wind turbine, wind turbine and associated method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0200530 A1 - Document ID: US20240200530A1 - Status: Published application - Kind: A1 - Application number: 18/544,040 - Filed: 2023-12-18 - Published: 2024-06-20 - Earliest claimed: 2022-12-19 - Applicants: Wobben Properties GmbH - Inventors: Dimitrios Bekiropoulos; Christoph Scheit; Jochen Stemberg - Web page: https://patentgrep.com/patent/US20240200530A1 ## CPC - F03D 1/0641: {of the section profile of the blades, i.e. aerofoil profile} - F03D 1/069: {of the trailing edge region} - F03D 1/0645: {of the trailing edge region} - F03D 1/06495: {Aerodynamic elements attached to or formed with the blade, e.g. flaps, vortex generators or noise reducers} - F05B 2230/23: by permanently joining parts together - F05B 2230/60: Assembly methods - F05B 2240/301: Cross-section characteristics - F05B 2240/3042: Serrated trailing edge - F05B 2250/12: rectangular - F05B 2250/20: three-dimensional - F05B 2260/96: Preventing, counteracting or reducing vibration or noise - Y02E 10/72: Wind turbines with rotation axis in wind direction - F03D: WIND MOTORS - F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Some embodiments relate to a rotor blade of a wind turbine, a wind turbine having a rotor blade and a method for optimizing a rotor blade. Some embodiments relate to a rotor blade of a wind turbine, wherein the rotor blade has a leading edge, a trailing edge, a suction side and a pressure side, and extends in a longitudinal direction of a rotor blade between a root end and a tip end, wherein a direct connection between the leading edge and the trailing edge is termed the chord line and the length thereof is termed the chord length, wherein the rotor blade has at least one airfoil element, wherein the at least one airfoil element is arranged at the trailing edge with a proximal portion adjoining a trailing edge region and projects from the trailing edge with a distal portion having a projecting direction, which is oriented substantially parallel to the direction of the chord length, wherein the at least one airfoil element has an airfoil element thickness in a direction perpendicular to the projecting direction, wherein the at least one airfoil element has a pressure side airfoil side facing the pressure side and a suction side airfoil side facing the suction side, wherein the at least one airfoil element has a cross-section substantially orthogonal to the projecting direction, characterized in that the cross-section of the at least one airfoil element has at least one local minimum of the airfoil element thickness, wherein the airfoil element thickness in the cross-section on both sides of the local minimum has a larger value. ## Claims ### Claim 1 A rotor blade of a wind turbine, wherein the rotor blade has a leading edge, a trailing edge, a suction side and a pressure side, and extends in a longitudinal direction of a rotor blade between a root end and a tip end, wherein a direct connection between the leading edge and the trailing edge is termed the chord line and the length thereof is termed the chord length, wherein the rotor blade has at least one airfoil element, wherein the at least one airfoil element is arranged at the trailing edge with a proximal portion adjoining a trailing edge region and projects from the trailing edge with a distal portion having a projecting direction, which is oriented substantially parallel to the direction of the chord length, wherein the at least one airfoil element has an airfoil element thickness in a direction perpendicular to the projecting direction, wherein the at least one airfoil element has a pressure side airfoil side facing the pressure side and a suction side airfoil side facing the suction side, wherein the at least one airfoil element has a cross-section substantially orthogonal to the projecting direction, wherein the cross-section of the at least one airfoil element has at least one local minimum of the airfoil element thickness, wherein the airfoil element thickness in the cross-section on both sides of the local minimum has a larger value. ### Claim 2 (depends on 1) The rotor blade according to claim 1, wherein the at least one airfoil element has multiple cross-sections at different positions in a direction parallel to the projecting direction, wherein each of the multiple cross-sections has at least one respective local minimum of the airfoil element thickness on a common line, wherein the connection of all local minimums on a common line is termed a groove, and wherein each of the multiple cross-sections has at least one respective local maximum of the airfoil element thickness on a common line, wherein the connection of all local maximums on a common line is termed a ridge line. ### Claim 3 (depends on 2) The rotor blade according to claim 2, wherein the at least one airfoil element has, for each groove: an airfoil surface located on the rotor blade root side of the individual grooves and extending between the respective groove and the ridge line, which is located on the same airfoil side directly on the rotor blade root side of the individual groove, wherein the airfoil surface has an airfoil element thickness decreasing in the direction of the rotor blade tip side, and an airfoil surface located on the rotor blade tip side of the individual grooves and extending between the respective groove and the ridge line, which is located on the same airfoil side directly on the rotor blade tip side of the individual groove, wherein the airfoil surface has an airfoil element thickness increasing in the direction of the rotor blade tip side, wherein each airfoil surface is formed convex, concave or straight. ### Claim 4 (depends on 2) The rotor blade according to claim 2, wherein the at least one airfoil element has a first airfoil surface on the pressure side airfoil side and/or on the suction side airfoil side, starting from a rotor blade root side, wherein the first airfoil surface has an airfoil element thickness increasing in the direction of the rotor blade tip side, and wherein the first airfoil surface reaches its maximum airfoil element thickness along a first ridge line, which extends parallel to the chord line, wherein each airfoil surface is formed convex, concave or straight. ### Claim 5 (depends on 2) The rotor blade according to claim 2, wherein the at least one airfoil element has a final airfoil surface on the pressure side airfoil side and/or on the suction side airfoil side, starting from a rotor blade root side, on the rotor blade tip side of the final ridge line, in the direction of the rotor blade tip side, wherein the final airfoil surface has an airfoil element thickness decreasing in the direction of the rotor blade tip side, and wherein the final airfoil surface reaches its minimum airfoil element thickness along the edge of the at least one airfoil element, wherein each airfoil surface is formed convex, concave or straight. ### Claim 6 (depends on 3) The rotor blade according to claim 3, wherein each airfoil surface of the at least one airfoil element extends from a distal end towards a proximal end of the at least one airfoil element. ### Claim 7 (depends on 3) The rotor blade according to claim 3, wherein each airfoil surface of the at least one airfoil element adjoining a groove is formed substantially congruent with the second airfoil surface adjoining the same groove. ### Claim 8 (depends on 2) The rotor blade according to claim 2, wherein at least one ridge line of the at least one airfoil element has a sharp edge. ### Claim 9 (depends on 2) The rotor blade according to claim 2, wherein at least one groove of the at least one airfoil element has a sharp edge. ### Claim 10 (depends on 2) The rotor blade according to claim 2, wherein each ridge line and each groove of the pressure side airfoil side of the at least one airfoil element is arranged perpendicularly with respect to the projecting direction in each point, below a respective ridge line and a respective groove of the suction side airfoil side of the at least one airfoil element. ### Claim 11 (depends on 1) The rotor blade according to claim 1, wherein the pressure side airfoil side of the at least one airfoil element is a reflection of the suction side airfoil side with respect to the plane spanned by the trailing edge and the projecting direction. ### Claim 12 (depends on 1) The rotor blade according to claim 1, wherein the proximal portion and the distal portion of the at least one airfoil element are formed in the shape of arrowheads, and wherein the proximal end and the distal end each are formed substantially round or pointed; for example, the proximal end may be pointed and the distal end may be round. ### Claim 13 (depends on 1) The rotor blade according to claim 1, wherein the proximal portion and the distal portion of the at least one airfoil element are formed from multiple arrowhead shapes arranged parallel to one another, wherein each arrowhead shape overlaps the directly adjacent arrowhead shape(s), and wherein for each arrowhead shape the proximal end and the distal end each are formed substantially round or pointed. ### Claim 14 (depends on 1) The rotor blade according to claim 1, wherein a mounting gap is formed between the pressure side airfoil side and the suction side airfoil side in the proximal portion, wherein the trailing edge region is at least partially arranged inside the mounting gap. ### Claim 15 (depends on 1) The rotor blade according to claim 1, wherein the at least one airfoil element is formed as two parts, wherein a first part has the pressure side airfoil side and a second part has the suction side airfoil side, wherein the first part is attached to the pressure side and the second part is attached to the suction side, preferably by gluing, wherein preferably the portions of the first part and the second part projecting from the trailing edge are attached together, preferably glued. ### Claim 16 (depends on 1) The rotor blade according to claim 1, wherein an element thickness forms between the pressure side airfoil side and the suction side airfoil side of the at least one airfoil element, and the element thickness increases from the proximal end towards a maximum element thickness at an airfoil element position and the element thickness decreases from this airfoil element position towards the distal end. ### Claim 17 (depends on 1) The rotor blade according to claim 1, comprising two or more airfoil elements that are arranged adjacent to one another along the trailing edges and abut against one another. ### Claim 18 (depends on 1) A wind turbine having a rotor blade according to claim 1. ### Claim 19 (depends on 18) A wind farm having multiple wind turbines according to claim 18. ### Claim 20 A method for optimizing a rotor blade, wherein the rotor blade has a leading edge, a trailing edge, a suction side and a pressure side, and extends in a longitudinal direction of a rotor blade between a root end and a tip end, wherein a direct connection between the leading edge and the trailing edge is termed the chord line and the length thereof is termed the chord length, comprising: assembling at least one airfoil element, wherein the at least one airfoil element is arranged at the trailing edge with a proximal portion adjoining a trailing edge region and projects from the trailing edge with a distal portion having a projecting direction, which is oriented substantially parallel to the direction of the chord length, wherein the at least one airfoil element has an airfoil element thickness in a direction perpendicular to the projecting direction between a plane spanned by the trailing edge and the projecting direction and the surface of the at least one airfoil element, wherein the at least one airfoil element has a pressure side airfoil side facing the pressure side and a suction side airfoil side facing the suction side, wherein the at least one airfoil element has a cross-section substantially orthogonal to the projecting direction, wherein the cross-section of the at least one airfoil element has at least one local minimum of the airfoil element thickness, wherein the airfoil element thickness in the cross-section on both sides of the local minimum has a larger value.