Turbojet engine nozzle for attenuating core and turbine noise
US4137992A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Dec 30, 1976 |
| Grant date | Feb 6, 1979 |
| Priority date | — |
| Expiry date | Dec 30, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T50/60
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Core noise, a low frequency noise component believed to be partly caused by the combustion processes within the engine, and turbine noise, a higher frequency noise component caused by the interaction of high velocity gases with the engine's turbine, are attenuated by noise absorbing structures that are disposed within the engine's nozzle and that in part define the physical geometry of the nozzle duct. The nozzle is formed of an outer sleeve and an inner generally bulb-shaped plug which are coaxially arranged to define an annular nozzle duct that channels the flow of gases rearwardly from the outlet of the engine's turbine. The plug has a hollow interior that is partitioned into a plurality of cavities that communicate with the nozzle duct via perforations provided in an outer wall of the plug. The size, shape and positioning of the interior cavities and outer plug wall perforations are selected so as to absorb noise energy existing in the exhaust gases, both at the relatively low frequencies characteristic of core noise and at the relatively higher frequencies characteristic of turbine noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.