Multi-layer acoustic linings
US4298090A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 1979 |
| Grant date | Nov 3, 1981 |
| Priority date | — |
| Expiry date | Nov 6, 1999 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02K1/827
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A multi-layer acoustic lining, e.g. for a flow duct in a gas turbine aeroengine, includes Helmholtz-type and tube-type resonators sandwiched between backing and facing sheets. In the invention, the ends of the tube-type resonators abut the Helmholtz resonators but are acoustically divided from them by partition means in such a way that the tube-type resonators differ from each other in resonant frequency. Variation of resonant frequency in the tube-type resonators is achieved by variation of their lengths according to which portion of the partition means acoustically divides them from the Helmholtz-type resonators, the partition means being arranged either step-wise or inclinedly between the backing and facing sheets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.