Vibro-acoustic treatment for engine noise suppression
US6358106B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 2000 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | May 15, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B77/13
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The vibro-acoustic energy produced by an engine is reduced by shrouding the powerhead with a blanket of material that both damps vibrations and absorbs acoustic wave energy. This vibro-acoustic treatment is applied on the inner surface or surfaces of a motor housing of a propulsion system. The housing is treated by adhering a sheet of acoustic barrier material to the housing inner surface. The acoustic barrier material is designed to block transmission therethrough of a substantial portion of impinging acoustic wave energy in a range from at least 1,000 to 3,000 hertz. The layer of adhesive material has a thickness such that impinging acoustic wave energy in a range of 1,000 to 3,000 hertz is efficiently converted into heat energy. An open-cell foam core laminated to the sheet of acoustic barrier material absorbs the trapped, blocked, acoustic wave energy. The open-cell foam core has an average pore size that is optimized to absorb acoustic wave energy in a range of 1,000 to 3,000 hertz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.