# US 2010/0166558 A1 · Methods and apparatus relating to improved turbine blade platform contours > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166558 A1 - Document ID: US20100166558A1 - Status: Published application - Kind: A1 - Application number: 12/347,341 - Filed: 2008-12-31 - Published: 2010-07-01 - Earliest claimed: 2008-12-31 - Assignees: General Electric Company - Inventors: Gunnar L. Siden; Craig A. Bielek; Brian C. Barr; Bradley T. Boyer; Thomas W. Vandeputte; Peter A. Galie - Web page: https://patentgrep.com/patent/US20100166558A1 ## CPC - F01D 5/145: {Means for influencing boundary layers or secondary circulations (for compressors F04D29/68)} - F01D 5/143: {Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour} - F05D 2240/80: Platforms for stationary or moving blades - 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) - 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 A flow directing assembly for use in a turbine engine comprising: a plurality of circumferentially spaced blades, each of the blades including a radial projecting airfoil with a concave pressure side and a convex suction side that extend from a platform; and a plurality of flow passages, each flow passage defined by the airfoils of neighboring blades and an inner wall formed by abutting platforms of neighboring blades, the inner wall forming the inner radial boundary of the flow passage; wherein the inner wall of one or more of the flow passages comprises means for reducing frictional losses between the flow through the turbine engine and the inner wall. The means for reducing frictional losses may comprise a non-axisymmetrical trough positioned between neighboring airfoils that is configured to reduce frictional losses. ## Claims ### Claim 1 A flow directing assembly for use in a turbine engine comprising: a plurality of circumferentially spaced blades, each of the blades including a radial projecting airfoil with a concave pressure side and a convex suction side that extend from a platform; and a plurality of flow passages, each flow passage defined by the airfoils of neighboring blades and an inner wall formed by abutting platforms of neighboring blades, the inner wall forming the inner radial boundary of the flow passage; wherein the inner wall of one or more of the flow passages comprises means for reducing frictional losses between the flow through the turbine engine and the inner wall. ### Claim 2 (depends on 1) The flow directing assembly according to claim 1, wherein: the means for reducing frictional losses comprises a non-axisymmetrical trough positioned between neighboring airfoils that is configured to reduce frictional losses; each of the troughs is circumferentially positioned between the airfoils of neighboring blades; and each of the troughs extends from an area between the leading edges of the airfoils to an area between the trailing edges of the airfoils. ### Claim 3 (depends on 1) The flow directing assembly according to claim 1, wherein: each of the troughs comprises a smoothly shaped elongated bowl-like depression formed in the inner wall; and the axis of the elongation of each of the troughs extends in an approximate axial direction. ### Claim 4 (depends on 1) The flow directing assembly according to claim 1, wherein: a first side of the trough is formed at or near the location on the inner wall where the pressure side of an first airfoil begins, the first side of the trough generally conforming to the shape that the pressure side of the first airfoil makes at the inner wall; a second side of the trough is formed at or near the location on the inner wall where the suction side of a second neighboring airfoil begins, the second side of the trough generally conforming to the shape that the suction side of the second airfoil makes at the inner wall; a third side of the trough is formed at or near a line extending between the leading edges of the first turbine blade and the second turbine blade; and a fourth side of the trough is formed at or near a line extending between the trailing edges of the first turbine blade and the second turbine blade. ### Claim 5 (depends on 4) The flow directing assembly according to claim 4, wherein each of the troughs slopes radially inward from a shallow radial depth at the perimeter of the trough to a maximum radial depth at the approximate center of the trough. ### Claim 6 (depends on 1) The flow directing assembly according to claim 1, wherein each of the troughs is disposed between the axial location of the leading edges and the axial location of the trailing edges of the airfoils within a row of blades. ### Claim 7 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough comprises a value within a range of about 0.0002 to 0.05 m. ### Claim 8 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough comprises a value within a range of about 0.0004 to 0.025 m. ### Claim 9 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough comprises a value within a range of about 0.001 to 0.01 m. ### Claim 10 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough divided by the radial height of the airfoils comprises a value within a range of about 0.001 to 0.05. ### Claim 11 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough divided by the radial height of the airfoils comprises a value within a range of about 0.0025 to 0.025. ### Claim 12 (depends on 1) The flow directing assembly according to claim 1, wherein the maximum radial depth of the trough divided by the radial height of the airfoils comprises a value within a range of about 0.005 to 0.01. ### Claim 13 (depends on 1) The flow directing assembly according to claim 1, wherein the trough forms the following described contour in the inner wall as it extends from an upstream termination point, which comprises approximately the same axial location as the leading edge of the airfoils, to a downstream termination point, which comprises approximately the same axial location as the trailing edges of the airfoils: from the upstream termination point the trough generally forms a smooth convex curve that extends in an inward radial direction; at a point approximately halfway between the upstream termination point and a maximum depth point, the trough smoothly transitions from a convex shape to a concave shape that continues in an inward radial direction; at the maximum depth point, the smooth concave curve continues, extending in an outward radial direction; and at a point approximately halfway between the maximum depth point and the downstream termination point, the trough smoothly transitions from a concave shape to a convex shape that continues in an outward radial direction until it reaches the downstream termination point. ### Claim 14 (depends on 13) The flow directing assembly according to claim 13, wherein the maximum depth point is located closer to the upstream termination point than the downstream termination point. ### Claim 15 (depends on 14) The flow directing assembly according to claim 14, wherein if the axial distance between the upstream termination point and the maximum depth point is divided by the axial distance between the upstream termination point and the downstream termination point, the value is within a range of about 0.1 and 0.9. ### Claim 16 (depends on 15) The flow directing assembly according to claim 15, wherein if the axial distance between the upstream termination point and the maximum depth point is divided by the axial distance between the upstream termination point and the downstream termination point, the value is within a range of about 0.25 and 0.75. ### Claim 17 (depends on 1) The flow directing assembly according to claim 1, wherein the trough forms the following described contour in the inner wall as it extends from a pressure side termination point, which comprises approximately the same circumferential location as the pressure side of the airfoils, to a suction side termination point, which comprises approximately the same circumferential location as the suction side of the neighboring airfoils: from the pressure side termination point the trough generally forms a smooth convex curve that extends in an inward radial direction; at a point approximately halfway between the pressure side termination point and a maximum depth point, the trough smoothly transitions from a convex shape to a concave shape that continues in an inward radial direction; at the maximum depth point, the smooth concave curve continues, extending in an outward radial direction; and at a point approximately halfway between the maximum depth point and the suction side termination point, the trough smoothly transitions from a concave shape to a convex shape that continues in an outward radial direction until it reaches the suction side termination point. ### Claim 18 (depends on 17) The flow directing assembly according to claim 17, wherein the maximum depth point is located closer to the suction side termination point than the pressure side termination point. ### Claim 19 (depends on 18) The flow directing assembly according to claim 18, wherein if the circumferential distance between the suction side termination point and the maximum depth point is divided by the circumferential distance between the suction side termination point and the pressure side termination point, the value is within a range of about 0.1 and 0.6. ### Claim 20 (depends on 18) The flow directing assembly according to claim 18, wherein if the circumferential distance between the suction side termination point and the maximum depth point is divided by the circumferential distance between the suction side termination point and the pressure side termination point, the value is within a range of about 0.2 and 0.5. ### Claim 21 (depends on 1) The flow directing assembly according to claim 1, further comprising a leading edge ridge, the leading edge ridge including an elongated raised area that resides approximately between the pressure side of the airfoil and the leading edge portions of the trough. ### Claim 22 (depends on 21) The flow directing assembly according to claim 21, wherein the axis of elongation of the leading edge ridge forms an angle of between approximately 30° and 60° with a line oriented in an axial direction. ### Claim 23 (depends on 22) The flow directing assembly according to claim 22, wherein the maximum radial height of the leading edge ridge is within a range of about 0.00002 and 0.05 m. ### Claim 24 (depends on 22) The flow directing assembly according to claim 22, wherein the maximum radial height of the leading edge ridge divided by the radial height of the airfoils comprises a value within the range of about 0.001 to 0.05.