US3820630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Jet exhaust noise suppressor
Assignee: National Aeronautics and Space Administration
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Filing: 1973-03-09
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Granted: 1974-06-28
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Expires: 1993-03-09
Abstract
Abstract Noise suppression for a jet engine exhaust is provided by an annular divergent body attached to an exhaust nozzle. The smallest diameter of the divergent body is larger than the diameter of the exhaust nozzle exit to form an annular step which produces a shock wave in the exhaust as it passes the step. An annular shroud is disposed around the divergent body and causes outside air to pass through voids in the divergent body to mix with the jet exhaust gas. The divergent body includes a plurality of channels with separators between the channels.
Inventors
- 👤 R Huff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:14
CPC Classifications
F; F02; F02K; F02K1/00; F02K1/46; F02K1/48; F02K1/38
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
Apparatus for suppressing the noise of a jet of gas being exhausted from the exhaust nozzle exit of a jet engine, said apparatus comprising: an annular body comprising a plurality of channel members separated by gutter members and attached to the nozzle and increasing in diameter in a downstream direction of the jet; means for producing a low pressure region around the exhaust nozzle exit; and an annular shroud disposed at the downstream end of said annular body said gutter members providing openings for the entrance of air into said exhaust jet.
Claim 2
Dependent Claim
92 words
Apparatus for suppressing the noise of a jet of gas being exhausted from the exhaust nozzle exit of a jet engine, said apparatus comprising: an annular body comprising a plurality of channel members separated by gutter members and attached to the nozzle and increasing in diameter in a downstream direction of the jet; means for producing a low pressure region around the exhaust nozzle exit; and an annular shroud disposed at the downstream end of said annular body said gutter members providing openings for the entrance of air into said exhaust jet.
Claim 3
Dependent Claim
24 words
The apparatus of claim 1 wherein said means for producing a low pressure region is an annular step formed at said exhaust nozzle exit.
Claim 4
Dependent Claim
24 words
The structure of claim 1 wherein each gutter has a longitudinally extending bottom edge substantially parallel to the longitudinal axis of said exhaust nozzle.
Claim 5
Dependent Claim
19 words
The apparatus of claim 1 wherein said gutter members have flat sides which intersect with a flat bottom surface.
Claim 6
Dependent Claim
16 words
The structure of claim 1 wherein said gutter members are longitudinally shorter than said channel members.
Claim 7
Dependent Claim
35 words
The structure of claim 1 and including a fairing disposed around the exhaust nozzle and terminating upstream of said shroud to provide an annular gap for the admission of air to said noise suppressing apparatus.
Claim 8
Dependent Claim
16 words
The structure of claim 1 wherein said channel members are flat longitudinal plates with flat sides.
Claim 9
Dependent Claim
37 words
The structure of claim 7 wherein the distance from the outer edge of the exhaust nozzle exit to the closest point of any channel ranges from about zero to one-eighth the diameter of the exhaust nozzle exit.
Claim 10
Dependent Claim
19 words
The structure of claim 8 wherein said distance is about one-twenty-fourth of the diameter Of the exhaust nozzle exit.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |