Multi-degree linear liner impedance testing device
US5377546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1992 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Jan 29, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/045
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for permitting evaluation of the acoustic impedance of liner designs used to attenuate noise in engine aircraft inlet and exhaust ducts, and in particular multiple degree of freedom designs of the type which include a porous facesheet followed by a backing depth followed by successive facesheet/backing depth combinations, includes a plurality of spacers of different thicknesses for varying the backing depths, and a movable plunger with a threaded adjustment mechanism for establishing the final backing depth. Gaskets and seals are installed at various interfaces to eliminate noise leakage paths. Two attachment bolts are used to hold the plunger assembly, face sheets, and spacers together, and an alignment disc positioned on the first facesheet is used to properly align an impedance tube waveguide on facesheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.