# US 10,502,076 B2 · Inter-turbine ducts with flow control mechanisms > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,076 B2 - Document ID: US10502076B2 - Status: Granted - Kind: B2 - Application number: 15/808,214 - Filed: 2017-11-09 - Published: 2019-05-09 - Granted: 2019-12-10 - Earliest claimed: 2017-11-09 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Vinayender Kuchana; Balamurugan Srinivasan; Craig Mckeever; Malak Fouad Malak - Web page: https://patentgrep.com/patent/US10502076B2 ## CPC - F01D 5/145: {Means for influencing boundary layers or secondary circulations (for compressors F04D29/68)} - F01D 9/041: {using blades (F01D5/148 takes precedence)} - F01D 9/02: Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} - F01D 9/04: forming ring or sector - F01D 25/28: Supporting or mounting arrangements, e.g. for turbine casing - F05D 2220/32: in gas turbines - F05D 2240/12: Fluid guiding means, e.g. vanes - F05D 2240/124: related to the suction side of a stator vane - F05D 2240/127: Vortex generators, turbulators, or the like, for mixing - F05D 2250/13: trapezoidal - 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 A turbine section is provided for a gas turbine engine. The turbine section is annular about a longitudinal axis. The turbine section includes a first turbine with a first inlet and a first outlet; a second turbine with a second inlet and a second outlet; an inter-turbine duct extending from the first outlet to the second inlet and configured to direct an air flow from the first turbine to the second turbine, the inter-turbine duct being defined by a hub and a shroud; and at least a first splitter blade disposed within the inter-turbine duct. The first splitter blade includes a pressure side facing the shroud, a suction side facing the hub, and at least one vortex generating structure positioned on the suction side. ## Claims ### Claim 1 A turbine section of a gas turbine engine, the turbine section being annular about a longitudinal axis, the turbine section comprising: a first turbine with a first inlet and a first outlet; a second turbine with a second inlet and a second outlet; an inter-turbine duct extending from the first outlet to the second inlet and configured to direct an air flow from the first turbine to the second turbine, the inter-turbine duct being defined by a hub and a shroud; and at least a first splitter blade disposed within the inter-turbine duct so as to be positioned between the hub and the shroud, the first splitter blade comprising a pressure side facing the shroud, a suction side facing the hub, and at least one vortex generating structure having a leading end opposite a trailing end positioned on the suction side that extends in a radial direction from a surface of the suction side toward the hub, the at least one vortex generating structure having a height that increases from the leading end to the trailing end. ### Claim 2 (depends on 1) The turbine section of claim 1, wherein the first splitter blade is the only splitter blade within the inter-turbine duct. ### Claim 3 (depends on 1) The turbine section of claim 1, wherein at least one vortex generating structure includes a plurality of the vortex generating structures arranged in a row. ### Claim 4 (depends on 3) The turbine section of claim 3, wherein each of the vortex generating structures are angled relative to a flow direction of the air flow through the inter-turbine duct. ### Claim 5 (depends on 3) The turbine section of claim 3, wherein each of the vortex generating structures is arranged parallel to one another. ### Claim 6 (depends on 5) The turbine section of claim 5, wherein the vortex generating structures are arranged such that co-rotating vortices are generated. ### Claim 7 (depends on 3) The turbine section of claim 3, wherein the vortex generating structures alternate with a first vortex generating structure arranged at a first angle relative to a flow direction of the air flow and a second vortex generating structure arranged at a second angle relative to the flow direction, the first angle being different than the second angle. ### Claim 8 (depends on 7) The turbine section of claim 7, wherein the vortex generating structures are arranged such that counter-rotating vortices are generated. ### Claim 9 (depends on 1) The turbine section of claim 1, wherein the at least one vortex generating structure is generally trapezoidal shaped. ### Claim 10 (depends on 1) The turbine section of claim 1, wherein the first splitter blade extends in axial-circumferential planes about the longitudinal axis. ### Claim 11 (depends on 1) The turbine section of claim 1, wherein the first splitter blade is generally parallel to a respective mean line curve. ### Claim 12 (depends on 1) The turbine section of claim 1, wherein the first splitter blade and the at least one vortex generating structure are passive flow control devices. ### Claim 13 (depends on 1) The turbine section of claim 1, wherein the first turbine is a high pressure turbine and the second turbine is a low pressure turbine. ### Claim 14 An inter-turbine duct extending between a first turbine having a first radial diameter and a second turbine having a second radial diameter, the first radial diameter being less than the second radial diameter, the inter-turbine duct comprising: a hub; a shroud circumscribing the hub to form a flow path fluidly coupled to the first turbine and the second turbine; and at least a first splitter blade disposed within the inter-turbine duct so as to be positioned between the hub and the shroud, the first splitter blade comprising a pressure side facing the shroud, a suction side facing the hub, and at least one vortex generating structure having a leading end opposite a trailing end positioned on the suction side that extends in a radial direction from the suction side toward the hub, the at least one vortex generating structure having a height that increases from the leading end to the trailing end. ### Claim 15 (depends on 14) The inter-turbine duct of claim 14, wherein at least one vortex generating structure includes a plurality of the vortex generating structures arranged in a row. ### Claim 16 (depends on 15) The inter-turbine duct of claim 15, wherein each of the vortex generating structures are angled relative to a flow direction of the air flow through the inter-turbine duct. ### Claim 17 (depends on 15) The inter-turbine duct of claim 15, wherein each of the vortex generating structures is arranged parallel to one another, and wherein the vortex generating structures are arranged such that co-rotating vortices are generated. ### Claim 18 (depends on 15) The inter-turbine duct of claim 15, wherein the vortex generating structures alternate with a first vortex generating structure arranged at a first angle relative to a flow direction of the air flow and a second vortex generating structure arranged at a second angle relative to the flow direction, the first angle being different than the second angle, and wherein the vortex generating structures are arranged such that counter-rotating vortices are generated. ### Claim 19 (depends on 14) The inter-turbine duct of claim 14, wherein the at least one vortex generating structure is generally trapezoidal shaped. ### Claim 20 (depends on 14) The inter-turbine duct of claim 14, wherein the first splitter blade and the at least one vortex generating structure are passive flow control devices.