Gas turbine exhaust having reduced jet noise
US9416752B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2012 |
| Grant date | Aug 16, 2016 |
| Priority date | — |
| Expiry date | Feb 25, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T50/60
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A gas turbine engine has an engine core and an annular by-pass duct, within a surrounding nacelle. An exhaust nozzle of the nacelle includes a selectively deployable noise-reduction section on an inner surface thereof. The noise-reduction section includes an inflatable envelope comprising a fixed outer wall and a displaceable inner wall. At least projections on the inner wall are inwardly displaced when the envelope is pressurized and retracted radially outwardly when the envelope is de-pressurized. When the envelope is pressurized, the inner wall includes portions that project to form a rough surface on the inner surface of the nacelle exhaust nozzle. This thickens the boundary layer and reduces the speed of the gas flow at the outer radius of the nozzle, thus reducing the differential velocity with the ambient air, which reduces the gradient throughout the shear layer thus reducing the noise level of the engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.