Jet exhaust noise reduction system and method
First Claim
1. A system for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising:
- a fan/core flow mixer having a plurality of mixer lobes each having a major peak and a major valley, and a common flow nozzle having a plurality of tabs each having a base end and a tip or tip edge center end, located along a circumferential edge of an aft end of the nozzle, wherein there is a predetermined clocking relationship between the plurality of mixer lobes and the plurality of nozzle tabs.
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Accused Products
Abstract
A system for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising a fan/core flow mixer having a plurality of mixer lobes and a common flow nozzle having an equal number of tabs located along a circumferential edge of an aft end of the nozzle. There is a predetermined clocking relationship between the plurality of mixer lobes and the plurality of nozzle tabs that results in reduced exhaust noise emission, most evident in the lower frequency range. A method for reducing jet noise emission from an internally mixed gas turbine engine exhaust comprises selectively aligning a circumferential distribution of a mixed flow vorticity field produced by a fan/core mixer with a circumferentially distributed exhaust flow vorticity field produced by a modified common flow nozzle at an exit plane of the engine exhaust.
42 Citations
24 Claims
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1. A system for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising:
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a fan/core flow mixer having a plurality of mixer lobes each having a major peak and a major valley, and a common flow nozzle having a plurality of tabs each having a base end and a tip or tip edge center end, located along a circumferential edge of an aft end of the nozzle, wherein there is a predetermined clocking relationship between the plurality of mixer lobes and the plurality of nozzle tabs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising:
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providing an internally mixed gas turbine engine including a fan/core flow mixer and an exhaust nozzle having a geometrically modified aft end protrusion;
generating via the flow mixer streamwise vorticity at a given circumferential location in an exit plane of the exhaust; and
generating via the geometrically modified aft end an exhaust flow streamwise vorticity at the given circumferential location in the exit plane of the exhaust. - View Dependent Claims (16)
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17. A method for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising:
selectively aligning a circumferential distribution of a mixed flow vorticity field produced by a fan/core mixer with a circumferentially distributed exhaust flow vorticity field produced by a modified common flow nozzle at an exit plane of the engine exhaust. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
Specification