JPS60237149A - Propelling force modulation apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an exhaust system for a cast turbine engine, and more particularly to a variable area exhaust nozzle and thrust reversal system for use with this engine.

BACKGROUND OF THE INVENTION The exhaust nozzle of a gas turbine engine generates a propulsive force by imparting a high velocity to the exhaust. This thrust is substantially opposite to the direction of the gas flow exiting the nozzle. In order to generate maximum thrust, it is advantageous to use a convergent/divergent (CD) nozzle.The cross-sectional area of the CD nozzle decreases downstream to the point of minimum area, called the throat, and then The primary converging part of the nozzle is designed to accelerate the flow to subsonic speeds until it reaches the throat, where it reaches sonic speeds. After this, the secondary diverging part accelerates the flow to supersonic speeds. To be able to control the expansion of

Performance can be improved by using variable geometry exhaust nozzles to modulate thrust. The variable shape nozzle is
Allows the dimensions of the throat area to change in response to changes in engine power settings and flight conditions such as wind speed and altitude. Typically, variable area nozzles are opened during takeoff to provide thrust build-up and closed at the appropriate altitude to provide the required cruise thrust.

A typical variable geometry nozzle has a number of flaps and seals arranged in an annular manner. Each flap has a converging member and a diverging member. A seal is positioned to cover the space between adjacent flaps. The flaps and seals together constitute the converging and diverging portions of the nozzle.

Another feature of the exhaust system is a thrust reversal device that modulates the thrust to a greater extent. A thrust reversal device is a means for reversing the direction of one jet stream to generate thrust in a reverse direction. A variety of different types of reversing devices are known, but most use the basic idea of occluding the backward flow and redirecting it laterally and forward.

One type of reversing device uses a cascade of vanes located in the exhaust duct upstream of the exhaust nozzle and uses various means to block the backward flow and expose the cascade.

Although such reversing devices have been used successfully, there are some problems. First, openings must be provided in the liner, casing, and outer shaping of the exhaust duct, and a cover door and actuating means for the door must be provided. Adds weight and complexity to the device.Furthermore, closure mechanisms used in conjunction with cascades tend to be heavy due to the relatively large area of flow that needs to be blocked.

In addition to the weight burden, such exhaust systems tend to increase efficiency losses due to increased gas leakage paths around the cascade cover door.

Another problem involves re-breathing the exhaust and causing the outgoing gases in the opposite direction to impinge on the fuselage. Rebreathing problems occur when reversal gases are sucked into the front of the engine. These gases hit the aircraft because the backflow cascade is located in front of the aircraft.

OBJECTS OF THE INVENTION It is an object of this invention to provide a new and improved thrust modulation device.

Another object of the invention is to provide a thrust reversal device that is lighter in weight than those previously known.

Another object of this invention is to provide a thrust reversal system for a gas turbine engine that reduces leakage paths for backward flow when the engine is in forward thrust mode.

Another object of this invention is to provide a variable area convergence/divergence nozzle in which the primary flap of the nozzle provides a blocking effect when in a reversal mode.

Another object of the invention is to provide a reversing device for a gas turbine engine that minimizes re-inhalation of reversing effluent gas.

Another object of the invention is to provide a variable area exhaust nozzle that allows full modulation of the nozzle area throughout all phases of forward and backward thrust.

Another object of the invention is to provide a thrust modulator having redundant means for housing the thrust reversal device.

The above-mentioned objects, features and advantages of this invention are as follows:
This will become clear from the detailed explanation below.

SUMMARY OF THE INVENTION One form of the invention provides a thrust modulator for mounting at the downstream end of an exhaust duct of a gas turbine engine. The device has a convergent/divergent exhaust nozzle, a plurality of counterflow cascade vanes, and a plurality of occlusion flaps. A nozzle defines the exit area of the flow. The cascade feathers
It is housed in a frame that has a front end and a rear end. The rear end of the frame is connected to the nozzle, and the rear end of the frame is slidably connectable to the exhaust duct. Each closure flap is pivotally attached to the nozzle in a first position. The nozzle and frame are axially translatable relative to the exhaust duct so that when in the forward retracted position substantially all of the engine's exhaust flow passes through the outlet area. When in the back layer U-port position, the flap cooperates with the cascade vane to direct a portion of the flow to the cascade vane.

DETAILED DESCRIPTION OF THE INVENTION The gas turbine engine shown in FIG. 1 includes a gas generator 14 and an exhaust duct 16. The gas turbine engine shown in FIG. Attached to the downstream end 18 of the exhaust duct 16 is one type of thrust modulator 20 of the present invention. The thrust modulator 20 is configured to adjust the flow rate 1ii224
It has an exhaust nozzle 22 that defines the exhaust nozzle. Hot gas from the gas generator 14 creates a stream 26 that is directed downstream by the exhaust duct 16 and passes through the outlet area 24 . Nozzle 22 imparts a relatively high velocity to stream 26 to
It is designed to increase thrust by 2゛.

Furthermore, the thrust modulator 20 has a frame 28 . The frame 28 includes a plurality of backflow cascade vanes 30 and a plurality of closure flaps 3.
It accommodates 2. As will be explained in more detail below, the nozzle 22 and frame 28 are axially translatable relative to the exhaust tact 16 such that substantially all of the engine's exhaust flow 26 passes through the exit area 24 when in the forward retracted position. It looks like this.

When in the rear deployed position shown in FIG.
cooperates with cascade vane 30 to direct a portion of flow 26 to cascade vane 30 .

2, 3, and 4 show thrust modulator 20 in more detail. A set of exhaust flaps 34 of exhaust nozzle 22 is shown in FIG. A set of exhaust seals 36 for exhaust nozzle 22 is shown in FIG.

It will be apparent to those skilled in the art that a variable area converging/diverging exhaust nozzle is comprised of a plurality of exhaust flaps and seals. The flap 34 and seal 36 overlap as shown in FIG. 2 to prevent exhaust gas from escaping therebetween during different operating phases of the engine. In the illustrated embodiment, the exhaust seal 36 is arranged concentrically with respect to the exhaust flap 34 and is slidably connected thereto by a hold-down means 38 .

The exhaust nozzle 22 is of convergent/divergent type. That is, nozzle 2
2 is composed of a primary convergence part, a secondary divergence part, and an outer part. The primary convergence portion is the primary flap 4 shown in Figure 4.
0a and a primary seal 40b shown in FIG. The secondary divergent portion includes a secondary flap 42a shown in FIG. 4 and a secondary seal 42b shown in FIG. The outer portion includes an outer flap 44a shown in FIG. 4 and an outer seal 44b shown in FIG. In this specification, the term "portion" refers to both the corresponding flap and closure.

As best shown in FIG. 4, the exhaust nozzle 22 has four
Contains a linkage consisting of a book stick. This link mechanism is
It is composed of a primary flap 40a, a secondary flap 42a, a compression link 46, and a rear frame member 48. These four members are connected by pivots 50a, 50b, 50c, and 50d.

The outlet area 24 of the exhaust nozzle 22 can be varied by a nozzle actuator 52. As shown in FIG. 4A, a nozzle actuator 52 is secured to the exhaust duct 16 at a first end 54 and in slidable contact with the exhaust nozzle 22 at a second end 56. The second end 56 has an annular actuation ring 57 that follows the cam surface 58. A first force 6 that causes the flow 26 to increase the exit area 24 relative to the nozzle 22
Generates 0. Nozzle actuator 52 generates a second force that contracts outlet area 24 . For this reason, the nozzle actuating device 5
The second end 56 of the ring 5 expands axially rearward, causing the second end 56 of the ring 5
7 from position 64a to position 64b causes nozzle 22 to pivot outwardly about point 50d. The action of the compression link 46 causes the secondary flap 42a to pivot outwardly, enlarging the exit area 24. Similarly, work @'3A place 5
When the second end 56 of the second end 56 is pulled axially forward, a second force 62 on the cam surface 58 acts to contract the exit area 24.

Thrust modulator 20 also includes a frame 28 containing a plurality of counterflow cascade vanes 30. As shown in FIGS. 4 and 5, the frame 28 has a front end or frame member 66, a rear end or frame member 48,
and a plurality of axially oriented slinkers 68 joining ends 66,48.

In the illustrated embodiment, the end 66.48 can be in the form of a 360 degree ring. The rear end 48 is the pivot point 50c, 5
It is connected to the nozzle 22 at 0d. The front end 66 is the support means 7
2, it can be movably connected to the exhaust duct 16. Fifth
As shown, adjacent stringers 68, along with front and rear rings or ends 66.48, are attached to frame portion 72.
Configure.

It will be clear that a number of such frame portions 72 can be formed coaxially with respect to the exhaust nozzle 22. Depending on the particular period and requirements of the aircraft, at least one frame portion 72 has an opening with a plurality of counterflow cascade vanes. However, it may not be necessary to provide vanes in all parts formed in this way.

Thrust modulator 20 further includes a plurality of closure flaps 32 shown in FIGS. 3 and 3A. Each flap 32 is pivotally attached to the nozzle 22 at a first position 74 . 3rd A
A closure flap 32, shown in forward thrust mode, is retracted into a recess 76 in the secondary seal 42b. Alternatively, it is also conceivable for the closure flap 32 to be accommodated in the secondary flap 42a.

In response to the axial rearward translation of the nozzle 22, the closure flap 32 progressively deploys into the exit area 24. This is accomplished by closure flap deployment mechanism 78, which includes first link 80, second link 82, third link 84, and fourth link 86. A first link 80 is pivotally connected to the closure flap 32 at one end and a link 82 at the other end.
is pivoted to one end of the The other end of the link 82 is the secondary seal 42
b. One end of link 84 is connected to second link 82
The other end 88 is pivotally connected to an end 85 of the fourth link 86 . The end 88 is connected to the track 90 of the rear frame member 48.
It is restrained so that it slides inside. Similarly, an end 92 of the fourth link 86 connects to a track 94 connected to the exhaust duct 16.
It is restrained as if sliding inside.

A closure 36 is provided to allow exit area 24 to be changed as shown in FIG. 4A without deploying closure flap 32.
It may be necessary for the flaps 34 and 34 to have a similar geometrical similarity. For a given exit area, the axial and radial position of point 50b must coincide with end 85. Similarly, the axial and radial positions of point 50c and end 88, and the axial and radial positions of point 50a and position R74, must also match.

Thrust modulator 20 includes a reverser actuator 96 . A first end 98 of the actuator is secured to the exhaust duct 16;
A second end 100 is connected to the rear frame member 48 of the frame 28. Reverser actuator 96 acts to axially translate nozzle 22 and frame 28 relative to exhaust duct 16 . In the forward storage position shown in FIG. 3A, substantially all of the engine's exhaust flow passes through the outlet area 24. In the rear deployed position shown in FIG. 3, the closure flap 32 cooperates with the cascade vane 30 to direct a portion 27 of the flow 26 to the cascade vane.

A feature of the invention is the location of the exhaust duct liner 124 relative to the cascade vanes 30 and frame 28. In conventional thrust reversers, this liner must be interrupted at the reverser. As shown in FIGS. 4 and 4A, the liner 124 is continuous until the aftmost end 126 where the nozzle 22 leaves the exhaust duct 16.

In operation, as the reverser actuator 96 translates the nozzle 22 and frame 28 axially rearward, the closure flap deployment mechanism 78 initially translates a constant 1 degree rearwardly relative to the nozzle 22, and then a fourth The end 92 of the link 86 is pulled axially rearward along the track 94. Nozzle 2
2 has translated halfway, the end 92 of the fourth link contacts the stop 102 of the track 94. Further translation of the nozzle 22 causes the end 88 of the third link 84 to be pulled axially forward relative to the track 90, thus pulling the closure flap 32
The second link 82 and the first link 80 are moved so that the second link 82 and the first link 80 are expanded into the flow 26. Those skilled in the art will appreciate that trajectory 90.
It will be clear that it will be necessary to vary the length of 94 as well as the lengths of links 80, 82, 86.

FIG. 3A shows the cascade vanes 30 within the frame 28 in a generally radial or thrust boil position. That is,
As the nozzle 22 is translated backwards, a portion of the flow 26 can escape radially before the closure flap 32 is deployed, thus modulating or reducing the magnitude of the forward thrust.

Once the nozzle 22 reaches a partially deployed position such that the closure flap 32 begins to deploy into the exit area 24;
Rotation means 104, shown in FIG. 6, rotates vane 30 progressively forward in response to axial rearward translation of nozzle 22. The rotating means 104 rotates each cascade vane 3
A connecting link 107.1 whose ends are pivotally connected to the interlocking rod 106 and the tension link 108 at a point near the radially outer end 130 of the connecting link 1
A tension link 108 pivotally connected to 07 and link 10
8 and in which a fourth link 86 can slide. At a predetermined point of axial rearward translation of the nozzle 22, a stop 112 on the link 86 contacts the collar 110. Pivotally attaching the radially inner end 132 of each vane 30 to string 68 causes tension link 108 to rotate vane 30 forward.

As best shown in FIG. 3, when the closure flap 32 is deployed, the flow 26 through the exit area 24 is reduced.

As the closure flap 32 progressively deploys, the converging portion of the nozzle 22 acts as an occlusion, thus cooperating with the closure flap 32 to increase the flow of exhaust air through the cascade vanes 30.

In this way, the convergence part is the flow 26 when in the forward ■ - force mode.
It has two functions: to increase the speed of the engine, and to block the exhaust flow during reverse mode.

The nozzle actuator 52 allows the convergent/divergent nozzle 22
The area of flow can be changed. Nozzle actuator 5
The range of movement of the nozzle 22 due to the stroke change of 2 is shown in FIG. 4A. The stroke of the reverser actuator 96 must be used to translate the nozzle 22 to deploy the closure flap 32 and open the cascade vanes 30. However,
It will be appreciated that for thrust modulator 20 to operate properly, nozzle actuator 52 must move through the stroke at the same rate as reverser actuator 96.

When translating the nozzle 22, differential movement between the nozzle actuator 52 and the reverser actuator 96 is required if it is desired to change the exit section [24].

In order for the nozzle actuator 52 and the reverser actuator 96 to move at the same rate over the stroke, it is necessary to provide synchronization means. This means keeps the second end 114 of the reverser actuator 96 fixed relative to the second end 56 of the nozzle actuator 52. Therefore, the nozzle 22 and the frame 28 can be translated in the axial direction without changing the area of the nozzle 2. One type of synchronization means that may be used includes a motion transducer fixed to the reverser actuator @ 96 whose electrical feedback signal is provided to the nozzle actuator 52 .

Another feature of the invention is redundancy for returning the nozzle 22 to the front retracted position in the event of a failure of the reverser actuator 96. This redundancy is illustrated in FIG. 4 by limiting means 116. Limiting means 116 limits axial forward translation of nozzle actuator 52 relative to nozzle 22 and frame 28 .

Restriction means 116 may include a physical stop attached to rear frame member 48 . If the reversing device actuator 96 fails when deploying the nozzle 22, the nozzle actuator 5
2 and restriction means 116 cooperate to translate the nozzle 22 and frame 28 into the forward storage position.

Another feature of the invention is a means for limiting axial rearward translation of nozzle actuator 52. This means includes a lock nut 120 on the shaft of the actuator 52 and a physical stop 122 attached to the rear frame member 48. If nozzle actuator 52 receives an erroneous signal that causes it to go too far past position 64b, nut 120
2 to prevent such overshoot.

Although the invention has been described, various modifications can be made within the scope of the invention. For example, the number, size, and placement of the frame portions 72 housing the cascade vanes 30 can be selected appropriately to reduce the amount of backflow gas impinging on the aircraft. Furthermore, further control of the thrust can be achieved by providing separate actuation means for the cascade vanes 1fu30 in the form of cover doors or actuation louvers. In this way, by operating only selected portions of the cascade vanes 30, it is possible to modulate the thrust force to a greater extent, or it is also possible to operate the thrust force to a certain degree. The actuating means in such alternative embodiments may act independently of axial translation.

It will be apparent to those skilled in the art that the invention is not limited to the specific embodiments shown and described herein. The invention is equally applicable to thrust modulators having constant area nozzles. Further, the mechanical linkage mechanism described in this section is an example, and many alternative mechanical linkage mechanisms are possible.
It can be used.

The dimensions, proportions and structural relationships shown in the drawings are examples;
These illustrations are not to be construed as representing actual dimensions, proportions, or structural relationships used in the thrust modulators of the present invention.

It should be understood that this invention is limited only by the scope of the claims, and that various modifications and equivalents can be made within the scope thereof.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a gas turbine engine having a thrust modulator of one type in this defense, FIG. 2 is a sectional view of the thrust modulator of FIG. 1 taken along line 2--2 in FIG. 1, and FIG. is line 3 in Figure 2
3A is a view of the reversing device and closure flap of FIG. 3 in the fully deployed position; FIG. 4 is a view of the reversing device and closure flap of FIG. 3 in the retracted position; FIG. 4A is a view of the reversing device and variable area nozzle of FIG. 4 in the retracted position, and FIG. 5 is a view of the reversing device and variable area nozzle of FIG. I looked in the direction. A view of the cascade vanes of the reversing device, FIG. 6 is a diagram showing details of the means for rotating the cascade vanes. Description of main symbols 16: Exhaust duct 22: Exhaust nozzle 24: Outlet area 26: Flow 28 Two frames 30: Cascade vanes 32: Closure flap Patent applicant General Electric Company (76)
30) Iku Numa Toku 2j1 Picture 2 Tj43A Picture 36 Picture 4A Picture 44" Picture 5 Picture 6 Continued from page 10 Inventor Stephen Zhu Ato Stupner I0 Inventor Richard Wald A4ner Holateker Inventor: Jeremiah Paul A, Wurtz 1 Silica United States, 573 Levy Drive, Fairfield, Ohio Silica United States, 774 Asahi Silica United States, B/Kdale Drive, West Chester, Ohio , 121 a.m., Wayne La Drive, Cincinnati, Ohio

Claims (1)

[Scope of Claims] 1) A thrust modulator mounted at the downstream end of an exhaust duct of a gas turbine engine, having a convergent/divergent exhaust nozzle defining a flow exit area, and having a leading end and a trailing end. a frame having a rear end connected to the nozzle and a front end slidably connectable to the exhaust duct, the frame housing a plurality of counterflow cascade vanes and each pivoting to the nozzle in a first position; a plurality of closure flaps attached to the exhaust duct, the nozzle and frame being axially translatable relative to the exhaust duct so that substantially all of the engine exhaust flow is directed to the exhaust duct when in the forward retracted position. A thrust modulator, wherein the flap cooperates with the cascade vane to direct a portion of the flow to the cascade vane when passing through an exit area and in an aft deployed position. 2. The thrust modulator according to claim 1), wherein the rear end of the frame is pivotally attached to the nozzle, and the exit area of the nozzle is variable. 3) The thrust modulator according to claim 2), further comprising a nozzle actuating device that changes the area of the nozzle, the nozzle actuating device having first and second ends, and the nozzle actuating device changing the area of the nozzle. one end is fixed to the exhaust duct and a second end is in sliding contact with the nozzle, the flow exerts a first force on the nozzle increasing the area; a second actuator for reducing the area relative to the nozzle;
Thrust modulator that applies force. 4) The thrust modulator according to claim 1, further comprising link means for progressively deploying the closing flap into the flow in response to axial rearward translation of the nozzle. , a thrust modulation device, thus reducing the flow through said exit area. 5) The thrust modulator according to claim 1, further comprising rotation means for gradually rotating the blade forward in response to axial rearward translation of the nozzle. 6) In the thrust modulation device according to claim 4), the nozzle includes a primary converging portion and a secondary diverging portion pivotally attached to the primary portion at approximately the first position. a thrust modulator, wherein the converging portion cooperates with the closure flap to increase exhaust flow through the cascade vane when the closure flap is progressively deployed. 7) In a thrust modulator installed at the downstream end of the exhaust duct of a gas turbine engine, a front ring, a rear ring,
and a plurality of axially oriented stringers connecting the rings, the two adjacent stringers, the front ring and the rear ring forming a frame portion, and at least one portion having a plurality of reverse flow cascades. a frame in which the vanes are housed, a converging/divergent exhaust nozzle defining an exit area for the flow, and a plurality of closure flaps each pivotally connected to the nozzle, the front ring disposed in the exhaust air; slidably connectable to a duct, said rear ring being connected to a nozzle such that said nozzle and frame can be translated axially relative to the engine, said nozzle and frame being in said retracted position; At a time substantially all of the engine's exhaust passes through the outlet area, and the flap cooperates with the cascade vane to direct a portion of the flow to the cascade vane when the nozzle and frame are in the rear deployed position. Thrust modulator. 8) The thrust modulator according to claim 7), comprising cascade actuating means for opening and closing the cascade vanes in at least one of the sections, the means being operable independently of axial translation. There is a thrust modulator that determines the thrust vector. 9) a thrust modulator mounted at a downstream end of an exhaust duct of a gas turbine engine, the thrust modulator having an exhaust nozzle having a flow outlet area, a forward end and a trailing end, the trailing end being connected to the nozzle; a frame having a forward end slidably connected to the exhaust duct and housing a plurality of counterflow cascade vanes; a plurality of occlusion flaps each pivotally connected to the nozzle in a first position; a reversing device actuator having first and second ends, the first end being secured to the exhaust duct and the second end being connected to the frame; a nozzle actuating device for changing the area of the nozzle; the reversing device actuating device acts to translate the nozzle and the frame in an axial direction relative to the exhaust duct, and when in the forward retracted position; , when substantially the entire exhaust flow of the engine passes through the exit area and is in the aft deployment position;
the flap cooperates with the cascade vane to direct a portion of the flow to the cascade vane, and the nozzle actuator is affixed to the exhaust duct at the first end and at the second end. in sliding contact with the nozzle, the flow exerting a first force on the nozzle that increases the area, and the nozzle actuator applying a second force on the nozzle that decreases the area. A thrust modulation device that adds 10) In the thrust modulator according to claim 9), the second end of the reversing device actuator is kept fixed relative to the second end of the nozzle actuator, thereby 11, comprising synchronization means that allow the nozzle and the frame to be translated in the axial direction without changing the area;
f force modulator. 11) The thrust modulation device according to claim 9, further comprising a limiting means for limiting forward axial translation of the nozzle actuating device with respect to the nozzle and the frame; A thrust modulation device that uses cooperative action to translate the nozzle and frame to the front storage position.