# US 2017/0284207 A1 · Airfoil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284207 A1 - Document ID: US20170284207A1 - Status: Published application - Kind: A1 - Application number: 15/471,683 - Filed: 2017-03-28 - Published: 2017-10-05 - Earliest claimed: 2016-03-29 - Assignees: Ansaldo Energia Switzerland AG - Applicants: Ansaldo Energia Switzerland AG - Inventors: Shailendra NAIK; Christian SOMMER - Web page: https://patentgrep.com/patent/US20170284207A1 ## CPC - F01D 5/186: {Film cooling (F01D5/187 takes precedence)} - F01D 5/20: Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} - F05D 2220/32: in gas turbines - F05D 2240/30: Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor - F05D 2260/202: by film cooling - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An airfoil for a working fluid path of a turboengine extends along a spanwidth direction from a base to a tip. An aerodynamic body thereof includes a suction side surface, a pressure side surface, a leading edge, a trailing edge and a tip, the tip of the aerodynamic body having a tip cross section and a cross-sectional contour circumscribing the tip cross section. A rim extends to the tip of the airfoil and follows the cross-sectional contour on the pressure side, the suction side and extends over the leading edge of the airfoil, the rim delimiting a tip cavity which is open at the tip of the airfoil. The rim is further open at the trailing edge of the airfoil such that the tip cavity is open at the trailing edge of the airfoil. ## Claims ### Claim 1 An airfoil configured for a working fluid path of a turboengine, the airfoil extending along a spanwidth direction from a base to a tip, the airfoil comprising: an airfoil aerodynamic body, the aerodynamic body having a suction side surface, a pressure side surface, a leading edge, a trailing edge and a tip, said tip of the aerodynamic body having a tip cross section and a cross-sectional contour circumscribing the tip cross section; a rim disposed at the tip of the aerodynamic body and extending to the tip of the airfoil and following said cross-sectional contour on the pressure side, the suction side, and extending over the leading edge of the airfoil, the rim delimiting a tip cavity which is open at the tip of the airfoil, wherein the rim is open at the trailing edge of the airfoil such that the tip cavity is open at the trailing edge of the airfoil; and at least one fluid duct having a discharge orifice which opens out onto a bottom of the tip cavity through said discharge orifice, the at least one fluid duct being in arranged and configured as a film cooling duct. ### Claim 2 (depends on 1) The airfoil according to claim 1, wherein film cooling duct is arranged and configured to discharge a coolant with a velocity component directed from the leading edge to the trailing edge. ### Claim 3 (depends on 1) The airfoil according to claim 1, comprising: at least two film cooling ducts wherein at least one film cooling duct is provided to direct a coolant flow towards a section of the rim provided on the suction side of the airfoil, and at least one other film cooling duct is provided to direct a coolant flow towards a section of the rim provided on the pressure side of the airfoil. ### Claim 4 (depends on 1) The airfoil according to claim 1, wherein at least one fluid duct is in fluid communication with an interior of the aerodynamic body. ### Claim 5 (depends on 1) The airfoil according to claim 1, wherein the at least one first fluid duct comprises: a first discharge orifice located at a first distance from the rim; and at least one second fluid duct with a second discharge orifice being located at a larger distance from the rim than the first discharge orifice. ### Claim 6 (depends on 5) The airfoil according to claim 5, wherein the first discharge orifice of the at least one first fluid duct is located adjacent the rim. ### Claim 7 (depends on 6) The airfoil according to claim 6, wherein the first discharge orifice of the at least one first fluid duct is located adjacent the rim on the suction side of the airfoil. ### Claim 8 (depends on 5) The airfoil according to claim 5, wherein the first discharge orifice of the at least one first fluid duct is shaped by a cylindrical geometry and the second discharge orifice of the at least one second fluid duct is a fan-shaped orifice. ### Claim 9 (depends on 1) The airfoil according to claim 1, comprising: at least one further rim coolant duct having a discharge orifice provided on an outer contour of the aerodynamic body in the tip region of the aerodynamic body and adjacent the rim, wherein said at least one further rim coolant duct is provided with a geometry of the respective discharge orifice being shaped and arranged such as to discharge a coolant on the outer surface of the airfoil which includes velocity components directed to the tip of the airfoil as well as to the trailing edge, and to disperse the coolant over an outer surface of the rim. ### Claim 10 (depends on 1) The airfoil according to claim 1 comprising: at least in a trailing edge region of the airfoil, two sections of the rim disposed on opposite sides of an airfoil camber line, which diverge from the tip of the aerodynamic body to the tip of the airfoil, such that a view on the airfoil from the trailing edge resembles a tulip-shaped geometry. ### Claim 11 (depends on 1) The airfoil according to claim 1, wherein the rim, in a leading edge region, extends at least essentially parallel to the spanwidth direction of the airfoil from the tip of the aerodynamic body to the tip of the airfoil. ### Claim 12 (depends on 1) The airfoil according to claim 1, wherein a depth of the tip cavity, measured from the tip of the airfoil to the bottom of the cavity, is smaller at the trailing edge than at the leading edge. ### Claim 13 (depends on 12) The airfoil according to claim 12, wherein a depth of the tip cavity decreases continuously from the leading edge to the trailing edge. ### Claim 14 (depends on 1) The airfoil according to claim 1, wherein a trailing edge cross sectional area of the tip cavity taken at the trailing edge and perpendicular to a camber line is 60% or less than a center cross sectional area of the tip cavity taken at 50% of an airfoil chord length and perpendicular to the camber line. ### Claim 15 A blading member for a turboengine, the blading member comprising: a foot; and at least one airfoil, the airfoil extending along a spanwidth direction from a base to a tip, the base being connected to the foot of the blading member, wherein the airfoil includes: an airfoil aerodynamic body, the aerodynamic body having a suction side surface, a pressure side surface, a leading edge, a trailing edge and a tip, said tip of the aerodynamic body having a tip cross section and a cross-sectional contour circumscribing the tip cross section; a rim disposed at the tip of the aerodynamic body and extending to the tip of the airfoil and following said cross-sectional contour on the pressure side, the suction side, and extending over the leading edge of the airfoil, the rim delimiting a tip cavity which is open at the tip of the airfoil, wherein the rim is open at the trailing edge of the airfoil such that the tip cavity is open at the trailing edge of the airfoil; and at least one fluid duct having a discharge orifice which opens out onto a bottom of the tip cavity through said discharge orifice the at least one fluid duct being arranged and configured as a film cooling duct. ### Claim 16 (depends on 15) The blading member of claim 15, in combination with a turboengine, the turboengine comprising: a working fluid path, the airfoil be arranged therein.