# US 9,752,439 B2 · Gas turbine engine airfoil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,439 B2 - Document ID: US9752439B2 - Status: Granted - Kind: B2 - Application number: 14/996,351 - Filed: 2016-01-15 - Published: 2016-05-12 - Granted: 2017-09-05 - Earliest claimed: 2014-02-19 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Edward J. Gallagher; Lisa I. Brilliant; Joseph C. Straccia; Stanley J. Balamucki; Mark A. Stephens; Kate Hudon - Web page: https://patentgrep.com/patent/US9752439B2 ## CPC - F01D 5/141: {Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147)} - F04D 29/324: {Blades} - F05D 2220/32: in gas turbines - F05D 2260/40311: of the epicyclical, planetary or differential type - 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) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - 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 arrangement of a turbine engine according to an example of the present disclosure includes adjacent airfoils including pressure and suction sides extending in a radial direction from a 0% span position to a 100% span position. The airfoils have a relationship between a gap/chord ratio and span position that defines a curve with a gap/chord ratio having a portion with a negative slope. ## Claims ### Claim 1 An airfoil arrangement of a turbine engine comprising: adjacent airfoils including pressure and suction sides extending in a radial direction from a 0% span position to a 100% span position, wherein the airfoils have a relationship between a gap/chord ratio and span position that defines a curve with a gap/chord ratio having a portion with a negative slope, wherein the gap/chord ratio is less than 0.8 from 80% span to 100% span, and the adjacent airfoils are rotatable blades. ### Claim 2 (depends on 1) The airfoil arrangement according to claim 1, wherein the gap/chord ratio is less than 1.0 at each span position. ### Claim 3 (depends on 1) The airfoil arrangement according to claim 1, wherein the gap/chord ratio is less than 0.9 at 0% span. ### Claim 4 (depends on 1) The airfoil arrangement according to claim 1, wherein the gap/chord ratio is less than 0.7 at 0% span. ### Claim 5 (depends on 1) The airfoil arrangement according to claim 1, wherein the portion is from 80% span to 100% span. ### Claim 6 A compressor section comprising: a plurality of rotatable compressor blades and a plurality of compressor vanes arranged about an axis; wherein adjacent rotatable compressor blades include pressure and suction sides extending in a radial direction from a 0% span position to a 100% span position, wherein the adjacent rotatable compressor blades have a relationship between a gap/chord ratio and span position that defines a curve with a gap/chord ratio having a portion with a negative slope, wherein the gap/chord ratio is less than 1.04 from 80% span to 100% span. ### Claim 7 (depends on 6) The compressor section according to claim 6, wherein the gap/chord ratio is less than 0.7 at 0% span. ### Claim 8 (depends on 7) The compressor section according to claim 7, wherein the gap/chord ratio is less than 1.0 at each span position. ### Claim 9 (depends on 6) The compressor section according to claim 6, wherein the portion is from 80% span to 100% span. ### Claim 10 (depends on 9) The compressor section according to claim 9, wherein the portion is from 80% span to 100% span, the curve has another portion with a positive slope, and the gap/chord ratio is less than 0.8 at 100% span. ### Claim 11 A gas turbine engine comprising: a combustor section arranged between a compressor section and a turbine section; a fan section including an array of fan blades; and said compressor section including rotatable blades defining adjacent airfoils, the adjacent airfoils including pressure and suction sides extending in a radial direction from a 0% span position to a 100% span position, wherein the airfoils have a relationship between a gap/chord ratio and span position that defines a curve with a gap/chord ratio having a portion with a negative slope, and the gap/chord ratio is less than 1.04 from 80% span to 100% span, and the adjacent airfoils are rotatable blades. ### Claim 12 (depends on 11) The gas turbine engine according to claim 11, wherein the fan section includes twenty-six or fewer fan blades, and has a fan pressure ratio that is less than 1.55. ### Claim 13 (depends on 11) The gas turbine engine according to claim 11, wherein the airfoils are rotatable relative to an engine static structure. ### Claim 14 (depends on 11) The gas turbine engine according to claim 11, wherein the gap/chord ratio is greater than 0.6 at each span position. ### Claim 15 (depends on 11) The gas turbine engine according to claim 11, wherein the compressor section includes a first compressor section and a second compressor section, the second compressor section arranged immediately upstream of the combustor section, and the airfoils are provided in the first compressor section. ### Claim 16 (depends on 15) The gas turbine engine according to claim 15, wherein the first compressor section is immediately downstream from the fan section and is counter-rotating relative to the array of fan blades. ### Claim 17 (depends on 15) The gas turbine engine according to claim 15, wherein the gap/chord ratio is less than 0.8 at 100% span. ### Claim 18 (depends on 17) The gas turbine engine according to claim 17, wherein the portion is from 80% span to 100% span, the curve has another portion with a positive slope, and the gap/chord ratio is less than 0.8 at 0% span. ### Claim 19 (depends on 11) The gas turbine engine according to claim 11, comprising a gear arrangement configured to drive the fan section, wherein the turbine section is configured to drive the gear arrangement and the compressor section. ### Claim 20 (depends on 11) The gas turbine engine according to claim 11, wherein the gap/chord ratio is less than 0.9 at 0% span. ### Claim 21 (depends on 11) The gas turbine engine according to claim 11, wherein the portion is from 80% span to 100% span, and the curve has another portion with a positive slope.