# US 2019/0169998 A1 · Double wall turbine gas turbine engine blade cooling configuration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169998 A1 - Document ID: US20190169998A1 - Status: Published application - Kind: A1 - Application number: 15/832,491 - Filed: 2017-12-05 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Christopher Whitfield; Carey Clum; Dominic J. Mongillo, Jr. - Web page: https://patentgrep.com/patent/US20190169998A1 ## CPC - F01D 5/187: {Convection cooling} - F02C 9/18: by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} - F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) - F05D 2220/32: in gas turbines - F05D 2240/35: Combustors or associated equipment - F05D 2250/11: triangular - F05D 2250/13: trapezoidal - F05D 2250/14: elliptical - F05D 2250/185: serpentine-like - F05D 2260/201: by impingement of a fluid - F05D 2260/202: by film cooling - F05D 2260/204: by the use of microcircuits - F05D 2260/2212: by creating turbulence - 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) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - 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 includes pressure and suction side walls that extend in a chord-wise direction between leading and trailing edges. The pressure and suction side walls extend in a radial direction to provide an exterior airfoil surface. A core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a tip. A skin passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall. The hot side wall defines a portion of the exterior airfoil surface and the cold side wall defines a portion of the core passage. The core passage and the skin passage are configured to have a same direction of fluid flow. A resupply hole fluidly interconnects the core and skin passages. A centerline of the resupply hole is arranged at an acute angle relative to the direction of fluid flow in the core passage and is configured to provide a low turbulence flow region in the skin passage. ## Claims ### Claim 1 An airfoil comprising: pressure and suction side walls extending in a chord-wise direction between leading and trailing edges, the pressure and suction side walls extending in a radial direction to provide an exterior airfoil surface, a core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a tip, a skin passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall, the hot side wall defines a portion of the exterior airfoil surface, and the cold side wall defines a portion of the core passage, the core passage and the skin passage are configured to have a same direction of fluid flow, and a resupply hole fluidly interconnects the core and skin passages, a centerline of the resupply hole is arranged at an acute angle relative to the direction of fluid flow in the core passage and is configured to provide a low turbulence flow region in the skin passage. ### Claim 2 (depends on 1) The airfoil of claim 1, wherein the angle is in a range of 5°-45°. ### Claim 3 (depends on 1) The airfoil of claim 1, wherein the skin passage has an aspect ratio that may vary between 3:1≥H/W≥1:5, wherein H corresponds to a passage height and W corresponds to a passage width. ### Claim 4 (depends on 3) The airfoil of claim 3, wherein the passage height (H) is in a range of 0.010-0.200 inches (0.25-5.08 mm). ### Claim 5 (depends on 1) The airfoil of claim 1, wherein the resupply hole has an exit at the skin passage, the exit has a diffuser. ### Claim 6 (depends on 1) The airfoil of claim 1, comprising serpentine cooling passage having first, second and third cooling passages, the first and third cooling passages having a direction of fluid flow toward the tip, and the second cooling passage having a direction of fluid flow away from the tip, the core passage provided by one of the first, second and third cooling passages. ### Claim 7 (depends on 1) The airfoil of claim 1, wherein a film cooling hole extends from the skin passage to the exterior airfoil surface. ### Claim 8 (depends on 1) The airfoil of claim 1, wherein the airfoil is a turbine blade. ### Claim 9 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a kidney shape with a concave side and a convex side joined by opposing curved sides, and cooling fluid is configured to flow out of the exit from the concave side toward the convex side. ### Claim 10 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has an hourglass shape with a pair of concave sides joined by opposing curved sides, and cooling fluid is configured to flow out of the exit from one of the concave sides toward the other of the concave sides. ### Claim 11 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a kidney shape with a concave side and a flat side joined by opposing curved sides, and cooling fluid is configured to flow out of the exit from the concave side toward the flat side. ### Claim 12 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a tri-lobular shape with three concave sides joined by three curved sides, and cooling fluid is configured to flow out of the exit from one of the concave sides toward the one of the curved sides. ### Claim 13 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a triangular shape with three flat sides and three corners, and cooling fluid is configured to flow out of the exit from one of the three flat sides toward one of the three corners. ### Claim 14 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has an oval shape with major and minor axes, and cooling fluid is configured to flow out of the exit along the minor axis. ### Claim 15 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a flat oval shape with a pair of flat sides joined by opposing curved sides, and cooling fluid is configured to flow out of the exit from one of the flat sides toward the other of the flat sides. ### Claim 16 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a crescent shape with a concave side and a convex side joined at opposing corners, and cooling fluid is configured to flow out of the exit from the concave side toward the convex side. ### Claim 17 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a crescent shape with a concave side and a convex side joined at opposing corners, and cooling fluid is configured to flow out of the exit from the convex side toward the concave side. ### Claim 18 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a kidney shape with a concave side and a convex side joined by opposing curved sides, and cooling fluid is configured to flow out of the exit from the convex side toward the concave side. ### Claim 19 (depends on 1) The airfoil of claim 1, wherein the resupply hole includes an exit at the skin passage, a cross-section of the resupply hole has a diamond shape with four corners, and cooling fluid is configured to flow out of the exit from one of the four corners toward another of the four corners. ### Claim 20 A gas turbine engine comprising: a combustor section arranged fluidly between compressor and turbine sections; and an airfoil arranged in the turbine section, the airfoil including pressure and suction side walls extending in a chord-wise direction between leading and trailing edges, the pressure and suction side walls extending in a radial direction to provide an exterior airfoil surface, a core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a tip, a skin passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall, the hot side wall defines a portion of the exterior airfoil surface, and the cold side wall defines a portion of the core passage, the core passage and the skin passage are configured to receive a cooling fluid from the compressor section and have a same direction of fluid flow, and a resupply hole fluidly interconnects the core and skin passages, a centerline of the resupply hole is arranged at an acute angle relative to the direction of fluid flow in the core passage and is configured to provide a laminar flow region in the skin passage, wherein the angle is in a range of 5°-45°, wherein the skin passage has an aspect ratio that may vary between 3:1≥H/W≥1:5, wherein H corresponds to a passage height and W corresponds to a passage width, wherein the passage height (H) is in a range of 0.010-0.200 inches (0.25-5.08 mm).