# US 2021/0277785 A1 · Multi-walled airfoil core > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277785 A1 - Document ID: US20210277785A1 - Status: Published application - Kind: A1 - Application number: 17/322,211 - Filed: 2021-05-17 - Published: 2021-09-09 - Earliest claimed: 2018-10-01 - Assignees: Raytheon Technologies Corporation - Applicants: Raytheon Technologies Corporation - Inventors: Christopher J. Peters; Emma J. Place; Jeffrey J. DeGray; Dominic J. Mongillo; Timothy J. Jennings; Raymond Surace; Jeremy B. Fredette - Web page: https://patentgrep.com/patent/US20210277785A1 ## CPC - F01D 5/18: Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades - F01D 5/189: {the insert having a tubular cross-section, e.g. airfoil shape} - B22C 9/046: {Use of patterns which are eliminated by the liquid metal in the mould} - B22C 9/10: Cores; Manufacture or installation of cores {(breaker cores B22C9/084)} - B22C 9/103: {Multipart cores} - B22D 25/02: by its peculiarity of shape; of works of art {(cylinders, pistons B22D15/02)} - F05D 2220/32: in gas turbines - F05D 2230/211: by precision casting, e.g. microfusing or investment casting - F05D 2250/185: serpentine-like - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B) - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An airfoil core includes a first core portion that has a hybrid skin core, a tip flag core, and a trailing edge core. A second core portion has a serpentine core and a leading edge core. ## Claims ### Claim 1 An airfoil core, comprising: a first core portion having a hybrid skin core, a tip flag core, and a trailing edge core; and a second core portion having a serpentine core and a leading edge core. ### Claim 2 (depends on 1) The airfoil core of claim 1, wherein the hybrid skin core portion, tip flag core and trailing edge core are injection molded as a single structure. ### Claim 3 (depends on 1) The airfoil core of claim 1, wherein the serpentine core and the leading edge core are injection molded as a second single structure. ### Claim 4 (depends on 1) The airfoil core of claim 1, wherein the hybrid skin core is arranged along a suction side of the airfoil core and the serpentine core is arranged along a pressure side of the airfoil core, and the tip flag core extends axially from the hybrid skin core to a trailing end of the airfoil core radially outward of at least a portion of the serpentine core. ### Claim 5 (depends on 1) The airfoil core of claim 1, wherein a rod connects the serpentine core and the tip flag core. ### Claim 6 (depends on 1) The airfoil core of claim 1, wherein the hybrid skin core and trailing edge core are connected at an inlet. ### Claim 7 (depends on 1) The airfoil core of claim 1, wherein a rod connects the trailing edge core and the tip flag core. ### Claim 8 (depends on 1) The airfoil core of claim 1, wherein the trailing edge core and the tip flag core are connected via core material beyond the airfoil trailing edge. ### Claim 9 (depends on 1) The airfoil core of claim 1, wherein a rod extends from the leading edge core to a feature radially outward of the tip flag core. ### Claim 10 (depends on 9) The airfoil core of claim 9, wherein a second rod extends radially outward of the serpentine core to the feature. ### Claim 11 (depends on 1) The airfoil core of claim 1, wherein the core has a plurality of heat transfer augmentation features. ### Claim 12 (depends on 1) The airfoil core of claim 1, wherein the serpentine core is arranged radially inward of the tip flag core. ### Claim 13 (depends on 1) The airfoil core of claim 1, wherein the tip flag core extends between a pressure side and a suction side of the airfoil core along a portion of an axial length. ### Claim 14 (depends on 1) The airfoil core of claim 1, wherein the leading edge core is configured to form a plurality of cavities spaced radially along a leading edge. ### Claim 15 An airfoil, comprising: a body extending radially from a platform to a tip, axially from a leading edge to a trailing edge, and having a thickness between a pressure side and a suction side; a hybrid skin cooling passage arranged along the suction side; a tip flag cooling passage extending along the tip between the hybrid skin cooling passage and the trailing edge and in fluid communication with the hybrid skin cooling passage; and a trailing edge cooling passage extending from the platform to the tip flag cooling passage. ### Claim 16 (depends on 15) The airfoil of claim 15, wherein a serpentine cooling passage is arranged between the hybrid skin cooling passage and the pressure side. ### Claim 17 (depends on 16) The airfoil of claim 16, wherein the serpentine cooling passage has a turbulator on one passage surface. ### Claim 18 (depends on 16) The airfoil of claim 16, wherein the serpentine cooling passage is arranged radially inward of the tip flag cooling passage. ### Claim 19 (depends on 15) The airfoil of claim 15, wherein a port is formed in the leading edge cooling passage. ### Claim 20 (depends on 15) The airfoil of claim 15, wherein the tip flag cooling passage extends between the pressure side and the suction side along a portion of an axial length of the body.