# US 2016/0258302 A1 · Airfoil and method for managing pressure at tip of airfoil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0258302 A1 - Document ID: US20160258302A1 - Status: Published application - Kind: A1 - Application number: 14/639,374 - Filed: 2015-03-05 - Published: 2016-09-08 - Earliest claimed: 2015-03-05 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Adebukola Oluwaseun Benson; Lisa De Bellis; Xiuzhang James Zhang - Web page: https://patentgrep.com/patent/US20160258302A1 ## CPC - F01D 5/20: Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} - F01D 5/02: Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) - F01D 5/187: {Convection cooling} - F01D 5/3007: {of axial insertion type} - F05D 2220/31: in steam turbines - F05D 2230/60: Assembly methods - F05D 2240/12: Fluid guiding means, e.g. vanes - F05D 2240/307: related to the tip of a rotor blade - F05D 2250/711: convex - F05D 2250/712: concave - F05D 2260/20: Heat transfer, e.g. 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 includes a squealer tip at an outer radial end of the airfoil. A squealer tip pocket of the squealer tip has a convex side and a concave side, and a tip plate. A divider extends across the tip plate from the concave side to the convex side to divide the squealer tip pocket into a first pocket and a second pocket. At least one cooling passage through the tip plate in the second pocket provides fluid communication through the tip plate from an interior of the airfoil to the second pocket. The first pocket is fluidically disconnected from the interior of the airfoil. ## Claims ### Claim 1 An airfoil comprising: a squealer tip at an outer radial end of the airfoil, a squealer tip pocket of the squealer tip having a convex side and a concave side; a tip plate at the squealer tip; a divider that extends across the tip plate from the concave side to the convex side to divide the squealer tip pocket into a first pocket and a second pocket; and, at least one cooling passage through the tip plate in the second pocket to provide fluid communication through the tip plate from an interior of the airfoil to the second pocket; wherein the first pocket is fluidically disconnected from the interior of the airfoil. ### Claim 2 (depends on 1) The airfoil of claim 1 including a camber line extending from a leading edge to a trailing edge of the airfoil, wherein the divider crosses the camber line of the airfoil. ### Claim 3 (depends on 2) The airfoil of claim 2, wherein a ratio of static pressure at the divider to an average total pressure at an inlet of the airfoil is approximately 0.55 to approximately 0.75. ### Claim 4 (depends on 2) The airfoil of claim 2, wherein the divider is positioned at a location along the camber line closer to the leading edge than the trailing edge. ### Claim 5 (depends on 2) The airfoil of claim 2, wherein the first pocket extends in a streamwise direction from the leading edge to approximately 10% to 40% along the camber line. ### Claim 6 (depends on 1) The airfoil of claim 1, further comprising a rim that extends radially outward from the tip plate and surrounds at least a portion of the tip plate, wherein the divider connects to the rim on the concave side and connects to the rim on the convex side. ### Claim 7 (depends on 6) The airfoil of claim 6, further comprising at least one fluid passage through the rim. ### Claim 8 (depends on 7) The airfoil of claim 7, wherein one fluid passage amongst the at least one fluid passage is adjacent the divider in the first pocket. ### Claim 9 (depends on 1) The airfoil of claim 1, wherein the tip plate in the first pocket is imperforate. ### Claim 10 (depends on 1) The airfoil of claim 1, wherein the at least one cooling passage includes a plurality of cooling passages. ### Claim 11 (depends on 1) The airfoil of claim 1, wherein the first pocket experiences higher pressures than the second pocket in use. ### Claim 12 (depends on 1) The airfoil of claim 1, further comprising a leading edge cavity within an interior of the airfoil, the first pocket axially aligned with and positioned radially outward of the leading edge cavity in a spanwise direction of the airfoil. ### Claim 13 (depends on 12) The airfoil of claim 12, further comprising a redirection flow path fluidically connecting the leading edge cavity to a cooling passage amongst the at least one cooling passage in the second pocket. ### Claim 14 (depends on 12) The airfoil of claim 12, wherein a cooling passage in the first pocket is plugged to prevent fluid communication between the leading edge cavity and the first pocket. ### Claim 15 A rotor blade comprising: a dovetail operatively configured to connect to a rotor wheel; and, an airfoil including: a squealer tip at an outer radial end of the airfoil, a squealer tip pocket of the squealer tip having a convex side and a concave side; a tip plate at the squealer tip; a divider that extends across the tip plate from the concave side to the convex side to divide the squealer tip pocket into a first pocket and a second pocket; and, at least one cooling passage through the tip plate in the second pocket to provide fluid communication through the tip plate from an interior of the airfoil to the second pocket; wherein the first pocket is fluidically disconnected from the interior of the airfoil. ### Claim 16 (depends on 15) The rotor blade of claim 15, wherein a ratio of static pressure at the divider to an average total pressure at an inlet of the airfoil is approximately 0.55 to approximately 0.75. ### Claim 17 A method of managing pressure at a tip of an airfoil, the method comprising: placing a divider across a tip plate in a squealer tip pocket of the airfoil from a concave side to a convex side of the tip to divide the tip pocket into a first pocket and a second pocket; fluidically blocking an interior of the airfoil from the first pocket; and, fluidically connecting at least one cooling passage through the tip plate in the second pocket to provide fluid communication through the tip plate from an interior of the airfoil to the second pocket. ### Claim 18 (depends on 17) The method of claim 17, wherein fluidically blocking the interior of the airfoil from the first pocket includes at least one of plugging a cooling passage in the first pocket from a leading edge cavity and fluidically connecting a pathway from the leading edge cavity to a cooling passage amongst the at least one cooling passage in the second pocket. ### Claim 19 (depends on 17) The method of claim 17, wherein placing the divider includes placing the divider where a ratio of static pressure at the divider to an average total pressure at an inlet of the airfoil is approximately 0.55 to approximately 0.75. ### Claim 20 (depends on 17) The method of claim 17, further comprising directing cooling air from the interior of the airfoil to the squealer tip pocket through lower pressures found in the second pocket and avoiding higher pressures found in the first pocket.