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US 10,107,191 B2Granted
Geared gas turbine engine with reduced fan noise
AssigneeUnited Technologies Corporation
InventorsJonthan Gilson, Burce L. Morin, Ramons A. Reba, David A. Topol, Wesley K. Lord
Life of this patent
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Abstract
A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.
Claims30
A gas turbine engine comprising:
- a fan section having a plurality of fan blades, said fan section having a low fan pressure ratio of less than 1.45, wherein the low fan pressure ratio is measured across one of said fan blades alone;
- a geared arrangement that drives said fan section;
- a compressor section including a first compressor section and a second compressor section;
- a turbine section including a first turbine section that drives said first compressor section, and a second turbine section that drives said second compressor section and said geared arrangement;
- a plurality of exit guide vanes positioned downstream of said fan blades;
- wherein a first ratio of a number of exit guide vanes to a number of fan blades being between 0.8 and 2.5;
- and
- wherein said exit guide vanes are provided with sweep and lean,
- wherein sweep means that:
- (a) an outer periphery of said exit guide vane is positioned to be downstream of a location of an inner periphery of said exit guide vane;
- and (b) a sweep angle is between 15 degrees and 30 degrees, and
- wherein lean means that:
- (a) an outer periphery of said exit guide vane is positioned at a greater circumferential distance than an inner periphery of said exit guide vane in a direction of rotation of said fan blades;
- and (b) a lean angle is greater than or equal to 2 degrees and less than or equal to 15 degrees.
11 more elements
A gas turbine engine comprising:
- a fan section having a plurality of fan blades, said fan section having a low fan pressure ratio of less than 1.45, wherein the low fan pressure ratio is measured across one of said fan blades alone;
- a geared arrangement that drives said fan section;
- a compressor section including a first compressor section and a second compressor section;
- a turbine section including a first turbine section that drives said first compressor section, and a second turbine section that drives said second compressor section and said geared arrangement;
- a plurality of exit guide vanes positioned downstream of said fan blades;
- wherein a first ratio of a number of exit guide vanes to a number of fan blades being between 0.8 and 2.0;
- and
- wherein said exit guide vanes are provided with sweep and lean,
- wherein sweep means that:
- (a) an outer periphery of said exit guide vane is positioned to be downstream of a location of an inner periphery of said exit guide vane;
- and (b) a sweep angle is between 5 degrees and 35 degrees,
- wherein lean means that:
- (a) an outer periphery of said exit guide vane is positioned at a greater circumferential distance than an inner periphery of said exit guide vane in a direction of rotation of said fan blades;
- and (b) a lean angle is greater than or equal to 2 degrees and less than or equal to 15 degrees.
11 more elements
A gas turbine engine comprising:
- a fan section having a plurality of fan blades;
- a geared arrangement that drives said fan section;
- a compressor section including a first compressor section and a second compressor section;
- a turbine section including a first turbine section that drives said first compressor section, and a second turbine section that drives said second compressor section and said geared arrangement;
- a plurality of exit guide vanes positioned downstream of said fan blades;
- wherein a first ratio of a number of exit guide vanes to a number of fan blades being between 0.8 and 2.5;
- wherein said exit guide vanes are provided with sweep and lean,
- wherein sweep means that:
- (a) an outer periphery of said exit guide vane is positioned to be downstream of a location of an inner periphery of said exit guide vane;
- and (b) a sweep angle is between 5 degrees and 35 degrees,
- wherein lean means that:
- (a) an outer periphery of said exit guide vane is positioned at a greater circumferential distance than an inner periphery of said exit guide vane in a direction of rotation of said fan blades;
- and (b) a lean angle is greater than 0 degrees and less than or equal to 15 degrees;
- and
- each of said exit guide vanes defines a hollow opening covered by an acoustic liner having a perforated face sheet;
- said face sheet has a thickness, and a diameter of holes in said face sheet is selected to be less than or equal to 0.3 of the thickness;
- and
- holes in said face sheet are at least 5% of a surface area of said face sheet.
15 more elements
Dependencies are inferred from the claim text.