US3780827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas turbine exhaust nozzle
Assignee: National Aeronautics and Space Administration
•
Filing: 1972-12-19
•
Granted: 1973-12-25
•
Expires: 1992-12-19
Abstract
Abstract An elongated hollow string is disposed in an exhaust nozzle combustion chamber and communicates with a source of air through hollow struts at one end. The other end of the string is bellmouth shaped and extends over the front portion of a nozzle plug. The bell-mouth may be formed by pivotally mounted flaps or leaves which are used to vary the exhaust throat area and the area between the plug and the leaves. Air from the engine inlet flows into the sting and also between the combustion chamber and a housing disposed around the chamber. The sting air cools the plug and serves as a low velocity inner core of secondary gas to provide noise reduction for the primary exhaust gas while the other air, when it exits from the nozzle, forms an outer low velocity layer to further reduce noise. The structure produces increased thrust in a turbojet or turbofan engine.
Inventors
- 👤 D Straight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:01
CPC Classifications
F; F02; F02K; F02K1/00; F02K1/38; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
106 words
A thrust increasing and noise reducing exhaust nozzle for a turbojet or turbofan engine comprising: an elongated shell attached at one end to said engine to receive exhaust gas therefrom; an elongated hollow body disposed in said shell, said body being closed at one end adjacent said engine and open at its other end; means for supplying high volume, low velocity, secondary gas to the interior of said elongated hollow body; a plug longitudinally positioned at said other end of said shell, said plug being of maximum size intermediate its ends, a forward portion of said plug extending into said other end of said elongated body.
Claim 2
Dependent Claim
106 words
A thrust increasing and noise reducing exhaust nozzle for a turbojet or turbofan engine comprising: an elongated shell attached at one end to said engine to receive exhaust gas therefrom; an elongated hollow body disposed in said shell, said body being closed at one end adjacent said engine and open at its other end; means for supplying high volume, low velocity, secondary gas to the interior of said elongated hollow body; a plug longitudinally positioned at said other end of said shell, said plug being of maximum size intermediate its ends, a forward portion of said plug extending into said other end of said elongated body.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 wherein said means for supplying high volume, low velocity gas is the fan of a turbofan engine.
Claim 4
Dependent Claim
23 words
The apparatus of claim 1 wherein said means for supplying high volume, low velocity gas is the air intake of a turbojet engine.
Claim 5
Dependent Claim
18 words
The apparatus of claim 1 wherein said other end of said elongated body is of generally bell-mouth shape.
Claim 6
Dependent Claim
58 words
The structure of claim 4 wherein said shell includes a longitudinally movable outer shroud having an inwardly extending annular hump, said shroud being positioned at said other end of said shell whereby said hump can be positioned upstream or downstream of the maximum size point of said plug to vary the throat area of the primary exhaust gas.
Claim 7
Dependent Claim
37 words
The apparatus of claim 4 wherein said other end of said shell is provided with a plurality of leaves pivotally mounted thereon for movement toward and away from said bell-mouth portion to vary the exhaust throat area.
Claim 8
Dependent Claim
103 words
The structure of claim 4 and including an afterburner; a sting liner disposed around said elongated body in spaced relationship, one end of said sting liner being upstream of said afterburner whereby turbine exhaust flows into the space between said sting liner and said elongated body, said sting liner being flared at its other end to maintain at the sPaced relationship from said flared other end of said elongated body; and a combustion chamber liner disposed inwardly of said shell in spaced relationship and extending from a point upstream of said afterburner to a point downstream of said maximum size of said plug.
Claim 9
Dependent Claim
17 words
The structure of claim 4 wherein said bell-mouth extends downstream past said maximum size of said plug.
Claim 10
Dependent Claim
50 words
The apparatus of claim 4 wherein said shell terminates at said other end as a plurality of scoops forming a corrugated inner ring and wherein said bell-mouth comprises an outwardly flared portion and scoops forming an inner corrugated ring which meshes in spaced apart relationship with said outer corrugated ring.
Claim 11
Dependent Claim
52 words
The apparatus of claim 1 wherein said other end of said elongated hollow body is outwardly flared and including a plurality of leaf members pivotally attached to said flared portion whereby the downstream ends of said leaves may be moved toward and away from said plug, and means for actuating said leaves.
Claim 12
Dependent Claim
99 words
The apparatus of claim 10 and including an afterburner; a sting liner disposed around said elongated body in spaced relationship, one end of said sting liner being upstream of said afterburner whereby turbine exhaust flows into the space between said sting liner and said elongated body, said sting liner being flared at its other end to maintain at the spaced relationship from said flared other end of said elongated body; and a combustion chamber liner disposed inwardly of said shell in spaced relationship and extending from a point upstream of said afterburner to a point upstream of said leaves.
Claim 13
Dependent Claim
34 words
The apparatus of claim 10 wherein said shell terminates at said other end as a plurality of scoops forming a corrugated outer ring and wherein said leaves are scoops forming a corrugated inner ring.
Claim 14
Dependent Claim
13 words
The apparatus of claim 1 and including means for longitudinally positioning said plug.
Claim 15
Dependent Claim
61 words
The structure of claim 1 and including a housing disposed around said shell in spaced relationship and hollow struts disposed between said shell and said elongated hollow body to place the interior of said hollow body in communication with the space between said shell and said housing, said space being in communication with said means for supplying low velocity secondary gas.
References Cited (Backward Citations)
FR796853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |