US3726091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound suppressing apparatus
Assignee: Rohr Inc
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Filing: 1971-02-16
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Granted: 1973-04-10
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Expires: 1991-02-16
Abstract
Abstract Engine of either turbo fan or turbo jet type is provided with multiple lobed exhaust nozzle. An ejector barrel defining a mixing zone is connected at its leading edge to the lobe tips adjacent to the nozzle exit plane to receive engine gases and free stream air. A plenum chamber in the forward portion of the barrel has inlet ports in flow communication with tip portions of lobes, and guide vanes extend forward into lobes to split the mixed engine gases and guide outer streams into plenum chamber inlet ports while inner streams flow directly to mixing zone. An annular exhaust slot is formed at the aft end of the plenum chamber to discharge high pressure gas into the intermediate section of the mixing zone. A plurality of control valve plates extend around the periphery of the slot and are individually controlled to open all or any part of the slot. When lower plates are open, the slot discharges an elongate stream of high pressure gas in the form of a trough-shaped shield to surround lower part of propulsion stream and reflect sound waves upward. Valves at one side may be opened to shield fuselage from noise. When all valves are opened, a complete gas sleeve is formed around the propulsion stream and improves thrust in addition to sound suppression. Gas for slot may be taken from turbine tail pipe for increased temperature. When air is used, afterburner may be employed to produce even higher temperature to enhance the reflective effectiveness of the shield.
Inventors
- 👤 R Tontini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:17
CPC Classifications
F; F02; F02K; F02K1/00; F02K1/28; F02K1/34; F02K1/36; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
181 words
Sound suppression and thrust augmentation apparatus for use in combination with a jet engine having an exhaust nozzle and an ejector barrel extending aft thereof; said barrel having radially spaced inner and outer walls defining a plenum chamber; inlet path means for the flow of free stream air to mix with the engine gases within the barrel; the inner wall of the barrel defining a mixing zone for the free stream air and the gases issuing from the nozzle; control nozzle means in the barrel extending substantially around the periphery of its inner wall; means to supply gas under pressure to the plenum chamber and thence to the control nozzle means; the latter being effective to discharge a stream of gas rearwardly along the inner wall of the barrel trailing section and selectively around the periphery of the stream to produce an elongate shield of high pressure gas extending rearwardly from the barrel to reflect a substantial portion of the sound waves in the propulsion stream inwardly thereof and to refract a substantial portion of the sound waves passing through it.
Claim 2
Dependent Claim
181 words
Sound suppression and thrust augmentation apparatus for use in combination with a jet engine having an exhaust nozzle and an ejector barrel extending aft thereof; said barrel having radially spaced inner and outer walls defining a plenum chamber; inlet path means for the flow of free stream air to mix with the engine gases within the barrel; the inner wall of the barrel defining a mixing zone for the free stream air and the gases issuing from the nozzle; control nozzle means in the barrel extending substantially around the periphery of its inner wall; means to supply gas under pressure to the plenum chamber and thence to the control nozzle means; the latter being effective to discharge a stream of gas rearwardly along the inner wall of the barrel trailing section and selectively around the periphery of the stream to produce an elongate shield of high pressure gas extending rearwardly from the barrel to reflect a substantial portion of the sound waves in the propulsion stream inwardly thereof and to refract a substantial portion of the sound waves passing through it.
Claim 3
Dependent Claim
45 words
Apparatus as claimed in claim 1; the means to supply gas to the control nozzle means comprising flow path means opening forwardly into the exhaust nozzle of the engine to receive a portion of the exhaust gases and transmit them to the control nozzle means.
Claim 4
Dependent Claim
43 words
Apparatus as claimed in claim 2; the engine being of the fan type and the nozzle containing turbine gas and fan air; and the flow path means being constructed and arranged to receive primarily fan air for transmission to the control nozzle means.
Claim 5
Dependent Claim
38 words
Apparatus as claimed in claim 3; and afterburner means located within the flow path means to supply fuel and burn it with the fan air to increase the temperature of the gas transmitted to the control nozzle means.
Claim 6
Dependent Claim
74 words
Apparatus as claimed in claim 1; the engine being of the fan type with a turbine tail pipe discharging turbine gases into the exhaust nozzle and a conduit discharging fan air into the exhaust nozzle; and the means to supply gas to the control nozzle means comprising conduits communicating at their forward ends directly with the interior of the turbine tail pipe and at their aft ends discharging turbine gases into the plenum chamber.
Claim 7
Dependent Claim
65 words
Apparatus as claimed in claim 1; the means to supply gas to the control nozzle means including said plenum chamber and defining an annular discharge slot around the periphery of the inner wall of the barrel; and the control nozzle means comprising a plurality of discrete control members individually operable to control the extent of opening and closing of selected portions of the discharge slot.
Claim 8
Dependent Claim
40 words
Apparatus as claimed in claim 6; the plenum chamber comprising a plurality of individual plenum chambers arranged in peripheral adjacency around the barrel; and one of the control members serving to control the discharge from each of said plenum chambers.
Claim 9
Dependent Claim
27 words
Apparatus as claimed in claim 6; each of the control members comprising a plate movable axially to cover and uncover a selected portion of the discharge slot.
Claim 10
Dependent Claim
125 words
Sound suppressing apparatus for use in combination with a jet engine having an exhaust nozzle, comprising: a generally annular housing coaxial with the engine and extending rearwardly to receive and control the propulsion gases issuing from the engine; means to define a rearwardly discharging exhaust slot in the inner wall of the housing forward of its trailing edge in a plane transverse to the engine axis and extending around the periphery of the inner wall or selectively around a portion thereof; and means to supply gas under pressure to the exhaust slot to flow rearwardly therefrom along the inner wall of the housing and produce a gaseous shield extending rearwardly from the housing to reflect sound waves in the propulsion gases in a selected direction.
Claim 11
Dependent Claim
125 words
Sound suppressing apparatus for use in combination with a jet engine having an exhaust nozzle, comprising: a generally annular housing coaxial with the engine and extending rearwardly to receive and control the propulsion gases issuing from the engine; means to define a rearwardly discharging exhaust slot in the inner wall of the housing forward of its trailing edge in a plane transverse to the engine axis and extending around the periphery of the inner wall or selectively around a portion thereof; and means to supply gas under pressure to the exhaust slot to flow rearwardly therefrom along the inner wall of the housing and produce a gaseous shield extending rearwardly from the housing to reflect sound waves in the propulsion gases in a selected direction.
Claim 12
Dependent Claim
39 words
Apparatus as claimed in claim 9; the means to supply gas to the exhaust slot comprising flow path means adapted to receive a portion of the propulsion gases at its forward end and transmit them to the exhaust slot.
Claim 13
Dependent Claim
19 words
Apparatus as claimed in claim 10; the flow path means being constructed and arranged to receive only turbine gases.
Claim 14
Dependent Claim
35 words
Apparatus as claimed in claim 10 and wherein the jet engine is of the fan bypass type and the flow path means being constructed and arranged to receive primarily bypass fan air from the engine.
Claim 15
Dependent Claim
51 words
Apparatus as claimed in claim 12; and afterburner means in the flow path means to supply fuel and burn it with the fan air to increase the temperature of the gas transmitted to the exhaust slot and thereby further augment the thrust and increase the reflective effectiveness of the gaseous shield.
Claim 16
Dependent Claim
28 words
Apparatus as claimed in claim 9; the means to define the exhaust slot including movable means to close the slot and to control the extent of its opening.
Claim 17
Dependent Claim
37 words
Apparatus as claimed in claim 9; the means to define the exhaust slot including movable means to vary the peripheral extent and the location of the slot around the periphery of the inner wall of the housing.
Claim 18
Dependent Claim
90 words
An ejector method of suppressing the sound of a jet engine, comprising the steps of discharging the engine gases rearwardly into a zone for mixing with free stream air, producing a peripheral gaseous shield or selectively a trough-shaped portion thereof having high velocity and directing it rearwardly aft of the engine and immediately adjacent to the propulsion stream of mixed air and engine gases to surround the latter and reflect some of the sound waves in the propulsion stream inwardly thereof and to refract other sound waves along the stream.
Claim 19
Dependent Claim
90 words
An ejector method of suppressing the sound of a jet engine, comprising the steps of discharging the engine gases rearwardly into a zone for mixing with free stream air, producing a peripheral gaseous shield or selectively a trough-shaped portion thereof having high velocity and directing it rearwardly aft of the engine and immediately adjacent to the propulsion stream of mixed air and engine gases to surround the latter and reflect some of the sound waves in the propulsion stream inwardly thereof and to refract other sound waves along the stream.
Claim 20
Dependent Claim
31 words
A method as claimed in claim 16; further including varying the location of the shield about the periphery of the propulsion stream to reflect the sound waves in a selected direction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |