Duct sound absorber
US11114080B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 2018 |
| Grant date | Sep 7, 2021 |
| Priority date | — |
| Expiry date | Feb 17, 2040 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60H2001/006
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
Sound absorption units for fluid ducts include two acoustically coupled pairs of Helmholtz resonators. The two resonators within each pair have identical resonance frequency, however the upstream resonator within each pair is partly filled with an acoustically lossy porous material, so that the upstream resonator within each pair has greater acoustic loss than its coupled downstream resonator. The upstream pair of resonators has a relatively low resonance frequency, while the downstream pair of resonators has a relatively high resonance frequency. The combination of frequency mismatch between the resonator pairs, and loss mismatch within each resonator pair, produces consistently high sound absorption across a broad frequency spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.