US3915413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable air inlet system for a gas turbine engine
Assignee: General Electric Co
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Filing: 1974-03-25
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Granted: 1975-10-28
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Expires: 1994-03-25
Abstract
Abstract A variable geometry inlet system is provided for a subsonic/supersonic gas turbine engine wherein a secondary inlet airflow is selectively ejected into a primary inlet airflow in order to augment the overall mass airflow to the engine and increase inlet pressure recovery. A plurality of foils are cooperatively disposed in rotatable connection with respect to a nacelle in order to modulate the secondary inlet airflow and match the velocity of the secondary airstream to that of the primary airstream thus reducing the mixing loss which would otherwise occur if the two streams commingled at different velocities. The primary and secondary inlet airstreams may also be maintained at a sufficiently high velocity to reduce the forward propagation of engine generated noise. The foils may also be rotated to define an outlet whereby a portion of the primary inlet airflow may be ejected overboard during supersonic operation to reduce aerodynamic drag as might otherwise result from a malfunctioning engine.
Inventors
- 👤 Donald Farley Sargisson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:03
CPC Classifications
B; B64; B64D; B64D33/00; B64D33/02; F; F02; F02C; F02C7/00; F02C7/04; F02C7/042; B64D2033/0253; B64D2033/026; F05; F05D; F05D2220/00; F05D2220/80; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10T; Y10T137/00; Y10T137/0536; Y10T137/0645
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
210 words
A variable air inlet system for a gas turbine engine comprising: a nacelle extending upstream of the engine so as to define a primary inlet at the upstream end thereof for receipt of a primary inlet airflow; at least one secondary air inlet in the nacelle upstream of the engine including an outside inlet foil portion rotatably hinged at a first hinge point to the nacelle, together with an inside inlet foil portion rotatably hinged at a different hinge point to the nacelle in spaced relation to the outside inlet foil portion such that the exterior surface of the inside inlet foil portion fairs into the nacelle to provide a substantially smooth flow surface and the outside inlet foil portion can be rotated outwardly away from the inside inlet foil portion to define in cooperation therewith a secondary inlet passageway gradually converging inwardly and then rearwardly to direct a secondary inlet airflow inwardly and then rearwardly along the inside of the nacelle, and means for continuously controlling the positions of the inside and outside inlet foil portions relative to each other so that the velocity of the secondary airflow ejected from the secondary passageway may be matched to the velocity of the primary airflow in order to reduce mixing losses.
Claim 2
Dependent Claim
210 words
A variable air inlet system for a gas turbine engine comprising: a nacelle extending upstream of the engine so as to define a primary inlet at the upstream end thereof for receipt of a primary inlet airflow; at least one secondary air inlet in the nacelle upstream of the engine including an outside inlet foil portion rotatably hinged at a first hinge point to the nacelle, together with an inside inlet foil portion rotatably hinged at a different hinge point to the nacelle in spaced relation to the outside inlet foil portion such that the exterior surface of the inside inlet foil portion fairs into the nacelle to provide a substantially smooth flow surface and the outside inlet foil portion can be rotated outwardly away from the inside inlet foil portion to define in cooperation therewith a secondary inlet passageway gradually converging inwardly and then rearwardly to direct a secondary inlet airflow inwardly and then rearwardly along the inside of the nacelle, and means for continuously controlling the positions of the inside and outside inlet foil portions relative to each other so that the velocity of the secondary airflow ejected from the secondary passageway may be matched to the velocity of the primary airflow in order to reduce mixing losses.
Claim 3
Dependent Claim
137 words
The variable air inlet system of claim 1 wherein the outside inlet foil portion is foldable having a forward foil member rotatably hinged to an aft foil member such that during low subsonic speeds the position of the forward and aft foil members are continuously controlled together with the position of the inside inlet foil portion so as to modulate the velocity of the secondary airflow through the passageway and during high subsonic speeds the position of the forward and aft foil members are continuously controlled, together with the position of the inside inlet foil portion so as to continue to modulate the velocity of the secondary airflow through the passageway in order to insure that the aerodynamic mixing of the primary and secondary airflows occurs at substantially equal velocities during both low and high subsonic speeds.
Claim 4
Dependent Claim
97 words
The variable air inlet system of claim 2 wherein the secondary air inlet includes a transverse support member in spaced relation from the upstream and downstream ends thereof and the upstream side of the support member pivotally receives the aft foil member of the outside foldable inlet foil portion and the downstream side of the support member pivotally receives an outside outlet foil portion which cooperates with an inside outlet foil portion rotatably disposed relative to the nacelle to provide an outlet passageway through which a portion of the primary inlet airflow may be selectively ejected overboard.
Claim 5
Dependent Claim
39 words
The variable air inlet system of claim 3 wherein there are provided a plurality of circumferentially spaced apart secondary inlets with longitudinal struts therebetween wherein the struts define a continuation of the nacelle and support the transverse support member.
Claim 6
Dependent Claim
112 words
The variable air inlet system of claim 3 wherein the primary inlet is of the supersonic type having an interior wall member with a forward converging portion connecting to an aft diverging portion together with a translatable centerplug centrally disposed within the interior wall and the outside outlet foil portion cooperates with an interior face of the support member together with the inside surface of the inside inlet foil portion to define the outside gradually diverging face of the outlet passageway with the inside face of the outlet passageway defined by the inside outlet foil portion in cooperation with an outwardly diverging wall member which interconnects the nacelle with the interior wall.
Claim 7
Dependent Claim
127 words
The variable air inlet system of claim 3 wherein the inside inlet foil portion, the inside outlet foil portion and the outside outlet foil portion are rotated by respective actuators and the outside foldable inlet foil portion is rotated by a power hinge which also connects through linkage means to the forward foil member in order to rotate the forward foil member simultaneous with and relative to the aft foil member and wherein the actuators and power hinge for the inlet foil portions are controlled as a function of the primary inlet subsonic airflow Mach number by a control which receives a signal from a primary inlet airflow Mach sensor with the outlet foil portions selectively opened at supersonic primary inlet airflow speeds to control aerodynamic drag.
Claim 8
Dependent Claim
152 words
The variable air inlet system of claim 2 wherein the nacelle includes an interior wall member spaced inward therefrom together with a transverse support member extending across the secondary inlet in spaced relation from the upstream and downstream ends thereof wherein the upstream side of the support member pivotally receives the aft foil member with the downstream side of the support member pivotally receiving an outside outlet foil portion which cooperates with an inside outlet foil portion rotatably connected to the interior wall member to provide an outlet passageway through which a portion of the primary inlet airflow may be selectively ejected overboard, and whereby the inside inlet foil portion is rotatably connected to the interior wall member in spaced apart opposing relation to the inside outlet foil portion such that the two inside foil portions can be rotated into engaging relation and thus block both the secondary inlet and outlet airflows.
Claim 9
Dependent Claim
44 words
The variable air inlet system of claim 7 wherein the primary inlet is of the supersonic type whereby the interior wall member includes a forward converging portion connecting to an aft diverging portion together with a translatable centerplug centrally disposed within the interior wall.
Claim 10
Dependent Claim
126 words
The variable air inlet system of claim 7 wherein the inside inlet foil portion, the inside outlet foil portion and the outside outlet foil portion are rotated by respective actuators and the outside foldable inlet foil portion is rotated by a power hinge which also connects through linkage means to the forward foil member in order to rotate the forward foil member simultaneous with and relative to the aft foil member wherein the actuators and power hinge for the inlet foil portions are controlled as a function of the primary inlet subsonic airflow Mach number by a control which receives a signal from a primary inlet airflow Mach sensor with the outlet foil portions selectively opened at supersonic primary inlet airflow speeds to control aerodynamic drag.
Claim 11
Dependent Claim
119 words
The variable air inlet system of claim 7 wherein the interior surfaces of the foil members of the outside inlet foil portion together with the inside outlet foil portion cooperatively define the outside face of the secondary inlet passageway with the inside face thereof defined by the exterior surface of the inside inlet foil portion, and wherein the outside outlet foil portion cooperates with the interior face of the support ring together with the inside surface of the inside inlet foil portion to define the outside gradually diverging face of the outlet passageway with the inside face thereof defined by the inside outlet foil portion in cooperation with an outwardly diverging wall member which interconnects nacelle and interior wall.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |