JP2003269253A - Variable fan nozzle apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable fan nozzle apparatus in which: (1) effect of promoting mixing of a fan flow with an external flow when a nozzle area is increased and fan noise is effectively reduced; (2) external resistance is minimized when the nozzle area is reduced; and (3) both of a thrust reverser and a variable fan nozzle are driven at any time only by a thrust reverser actuator. <P>SOLUTION: The variable fan nozzle apparatus comprises: a plurality of swing flaps 22 disposed to a fan outlet of a turbofan engine with their leading edges swingable around a shaft 21 circumscribed on a circle whose center is an engine axial line Z; and a swing apparatus 24 that makes the plurality of swing flaps swing around and in synchronization with the shaft. Further, a plurality of fixed flaps 23 are provided, and each fixed flap and each swing flap are alternately disposed in a circumferential direction along the fan outlet. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbofan engine, and more particularly to a variable fan nozzle device for a turbofan engine.

[0002]

2. Description of the Related Art A turbofan engine has a fan and a fan turbine for driving the fan in front of and behind a core engine including a compressor, a combustor, and a compressor turbine for driving the compressor.

In the turbofan engine, a part of the air compressed by the fan mounted on the front side of the core engine enters the core engine and the rest becomes a bypass air flow. The ratio of this bypass air flow rate to the air flow rate that passes through the core engine and is involved in combustion is called the bypass ratio. Turbofan engines with a large bypass ratio are excellent in both fuel economy and low noise, and for large passenger planes and transport aircraft that place importance on these, a high bypass ratio (4.5 to 8) A turbofan engine is being adopted.

In high bypass ratio turbofan engines,
The main method is to separate the bypass air from the exhaust of the core engine and discharge it directly to the atmosphere. In this case, the nozzle for bypass air (called a fan nozzle) was a fixed nozzle with a fixed area in the past, but a variable area fan exhaust nozzle with a variable nozzle area was created and applied to improve the performance of the fan nozzle. (JP-A-9-195)
853).

FIG. 5 is a block diagram of the "variable area fan exhaust nozzle" of Japanese Patent Laid-Open No. 9-195853.
(A) is an overall sectional view, and (B) is an enlarged view of a main part.

In FIG. 5A, 1 is a gas turbine engine, 2 is a core engine, 3 is a fan, 4 is a central axis,
5 is an annular nacelle, 6 is an outer nacelle, 7 is an upstream portion, 8 is a downstream portion, 9 is a core cowl, 10 is a duct, 11 is an exhaust nozzle, and 12 is an outer nacelle trailing edge.

As shown in FIG. 5 (B), the gas turbine engine 1 has a displacement sleeve 13, which is located downstream of the outer nacelle 6. The exhaust nozzle 11 is formed between the rear edge of the displacement sleeve 13 and the conical core cowl 9. The displacement sleeve 13 is displaced downstream and cooperates with the core cowl 9 having a reduced diameter to increase the area of the exhaust nozzle 11.

[0008]

However, the variable area fan exhaust nozzle (variable fan nozzle device) described above is used.
Then, it is necessary to provide the displacement sleeve actuator 15 for the displacement sleeve in addition to the thrust reverser actuator 14 for the thrust reversing mechanism, and since it is an additional device, the weight is increased, and the total adoption merit is small. It was

Further, even when the displacement sleeve 13 is located on the downstream side and the area of the exhaust nozzle 11 is increased, the nozzle shape is maintained in a donut shape, so that there is an effect of promoting the mixing of the fan flow and the external flow. There was little fan noise reduction effect.

The present invention was created to solve such problems. That is, the object of the present invention is to
(1) When the nozzle area is increased, the effect of promoting mixing of the fan flow and the external flow is high, and fan noise can be effectively reduced. (2) When the nozzle area is decreased, It is an object of the present invention to provide a variable fan nozzle device that can minimize resistance and (3) can drive both the thrust reverser and the variable fan nozzle at any time by using only the thrust reverser actuator.

[0011]

According to the present invention, a plurality of swingable shafts (21) provided at the fan outlet of a turbofan engine and having a leading edge circumscribing a circle centered on the engine axis Z are provided. A variable fan nozzle device is provided, comprising: an oscillating flap (22) and an oscillating device (24) for oscillating the plurality of oscillating flaps in synchronization around the shaft. It

According to this structure, the swing device (24) swings the plurality of swing flaps (22) synchronously around the shaft (21) circumscribing a circle centered on the engine axis Z. Thereby, the nozzle area of the fan nozzle formed by the trailing edge of the swing flap (22) can be varied.

According to a preferred embodiment of the present invention, there is provided a plurality of fixed flaps (23) provided at the fan outlet of the turbofan engine, the fixed flap and the swing flap being circumferentially arranged along the fan outlet. Are arranged alternately. With this configuration, when the swing flap (22) swings with respect to the fixed flap (23) to increase the nozzle area, the fan outlet becomes uneven, and due to this unevenness, the fan flow and the external flow are separated. It is possible to promote mixing and effectively reduce fan noise due to the fan flow.

The rocking device (24) includes the shaft (21).
A cowl (25) for swingably supporting the armature, a link mechanism (26) provided in the cowl for rocking the rocking flaps in synchronization, and a drive rod (27a) having a drive rod (27a) for axial movement. A direct acting actuator (27) for operating the link mechanism and a stopper (28) for limiting the swing range of the swing flap are provided. With this structure, the drive rod (27a) of the linear actuator (27) is moved in the axial direction, and the link mechanism (2) provided in the cowl (25) is moved.
6) can be operated to swing the swing flaps in synchronization. Further, the stopper (28) can mechanically limit the movement of the swing flap beyond the swing range.

The cowl (25) is a movable cowl which is movable from a normal position F adjacent to a fan nacelle (16) of a turbofan engine to a downstream reverse position R along an axis Z. The linear actuator (27) is attached to the fan nacelle (16), the drive rod (27a) extends from the fan nacelle into the moving cowl, and one end is supported by the drive rod (27a) to swing. A compression spring (29) for urging the moving cowl toward the fan nacelle is provided in the swing range of the flap. With this structure, the drive rod (27a) has one end supporting the movable cowl (25) movable from the normal position F adjacent to the fan nacelle (16) to the reverse position R on the downstream side along the axis Z. Compressed spring (2
In 9), the oscillating flap can be oscillated within its oscillating range while being urged and held to the fan nacelle side.

The linear actuator (27) has a stroke exceeding the swing range of the swing flap, and the link mechanism is operated within the swing range of the swing flap, and the stroke exceeding the swing range causes the stroke. Cowl (25)
Is moved to the downstream side from the normal position F to the reverse position R, and the thrust reversing mechanism (30) interlocked with this is operated. With this configuration, when the linear actuator (27) is operated while the swing flap exceeds its swing range and cannot mechanically move by the stopper (28), the stroke causes the cowl (25) to reverse from the normal position F. It is possible to move it to the position R to the downstream side and operate the thrust reversing mechanism (30) interlocking with it.

The thrust reversing mechanism (30) is fixed to the fan nacelle (16) to guide the fan flow to the outside upstream side, and the cascade (32) fixed to the moving cowl at the normal position F. A cascade cover (33) for covering the vehicle, a block door (34) swingably attached to the moving cowl, and a normal position F of the cowl.
And a link mechanism (35) that positions the block door at a position where the fan outlet is fully opened, and positions the block door at a cowl reverse position R where the fan outlet is fully closed.

With this structure, at the normal position F of the cowl (25), the cascade (32) is connected to the cascade cover (3).
3) to cover the block door (34) with the link mechanism (3
Position the fan outlet to the fully open position by 5),
Bypass air can be exhausted rearward from the fan outlet. When the cowl (25) moves to the reverse position R, the cascade cover (33) fixed to the moving cowl also moves rearward, and the cascade (32) is exposed. At the same time, the block mechanism (35) positions the block door (34) at the position where the fan outlet is fully closed by the link mechanism (35), and the bypass air can be guided to the outside upstream through the cascade (32) to perform the reverse operation.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common parts are designated by the same reference numerals and used.

1 and 2 are block diagrams of a variable fan nozzle device according to the present invention. FIG. 1 shows a cruising state and FIG. 2 shows takeoff and landing. 1 and 2, the variable fan nozzle device 20 of the present invention includes a plurality of swing flaps 2.
2. The swing device 24 and the fixed flap 23 (FIG. 2) are provided.

The plurality of swing flaps 22 are provided at the fan outlet of the turbofan engine, and their front edges are swingable about a shaft 21 circumscribing a circle centered on the engine axis Z. In addition, as shown in FIG. 2, a plurality of fixed flaps 23 are also provided at the fan outlet of the turbofan engine. However, the fixed flap 23
Is integrally formed with a cowl 25, which will be described later, so that it cannot swing. As shown in the figure, the swing flap 22 and the fixed flap 23 are flat plate-shaped members whose downstream side is gradually thinned. The swing flaps 22 and the fixed flaps 23 are alternately arranged in the circumferential direction along the fan outlet.

The swing device 24 is configured to swing a plurality of swing flaps around the shaft 21 in synchronization.
In this example, the rocking device 24 includes a cowl 25, a link mechanism 26, a linear motion actuator 27, and a stopper 28.

The cowl 25 is a part of an external nacelle which constitutes a fan outlet portion of a turbofan engine, and swingably supports a shaft 21 fixed to a front edge of a swing flap 22 at a rear end portion thereof.

The link mechanism 26 comprises link members 26a and 26b provided in the cowl 25.
By moving one end (lower end in the figure) of 6b back and forth (left and right in the figure), the link member 26a connected to the shaft 21 is swung about the shaft 21, and the swing flap 22 is set about the shaft 21. It is designed to rock. The shafts 21 of the plurality of swing flaps 22 or one ends of the link members 26b are connected to each other, and the plurality of swing flaps 22 operate in synchronization with each other.

The linear actuator 27 is used for the drive rod 2
7a. The tip portion (right end portion in the figure) of the drive rod 27a is connected to one end portion of the link member 26b,
The link mechanism 26 is operated by the axial movement.

The stopper 28 is the link member 2 in this example.
The swinging range of the swinging flap 22, which is a mechanical stopper material that limits the swinging range of 6a, is limited to the usable range. The stopper 28 is not limited to this embodiment, and may be provided on the cowl so as to limit the relative movement range of the collar member 27b provided on the drive rod 27a within the cowl 25, for example.

FIG. 3 is a block diagram of the variable fan nozzle device according to the present invention when the reverser is used. 1 to 3, in the variable fan nozzle device 20 of the present invention, the cowl 2
Reference numeral 5 denotes a moving cowl, which is configured to be movable from a normal position F adjacent to the fan nacelle 16 of the turbofan engine to a reverse position R on the downstream side along the axis Z.

Further, the direct acting actuator 27 is attached to the fan nacelle 16 on the main body side, and has a drive rod 27a.
Extends from the fan nacelle 16 into the moving cowl. The linear actuator 27 is preferably a hydraulic cylinder or a gas cylinder, but may be an electric cylinder, a ball screw, or the like. As shown in FIG. 2, the linear actuator 27 includes an actuator position sensor 36, a computing unit 37, and a fan state quantity sensor 38, and controls the actuator position according to the fan state quantity. Actuator position sensor 36
Includes, for example, a potentiometer, a linear encoder, and the like.

Further, the variable fan nozzle device 20 of the present invention.
Includes a compression spring 29 whose one end is supported by the collar member 27b of the drive rod 27a. The compression spring 29 biases the moving cowl 25 toward the fan nacelle in the swing range of the swing flap 22.

1 to 3, the linear actuator 27 has a stroke exceeding the swing range of the swing flap 22. Therefore, within the swinging range of the swinging flap 22, the linking mechanism 26 is operated by moving the drive rod 27a with the moving cowl 25 being urged to the fan nacelle side (normal position F) by the compression spring 29. Further, when the link mechanism 26 is mechanically fixed by the open side stopper 28, the cowl 25 is moved downstream from the normal position F to the reverse position R by a stroke exceeding the swing range, and the thrust reverser interlocked with this is moved. The mechanism 30 is operated.

1 to 3, the thrust reversing mechanism 30 comprises a cascade 32, a cascade cover 33, a block door 34 and a link mechanism 35.

The cascade 32 is fixed to the downstream side of the fan nacelle 16, and guides the fan flow from the inside to the outside upstream side to perform the reverse operation.

The cascade cover 33 has a movable cowl 25.
Is fixed on the upstream side of, and covers the cascade 32 at the normal position F to suppress its operation, and at the reverse position R of the cowl, the cascade cover 33 also moves rearward,
The cascade 32 is exposed and ready for operation.

The block door 34 is swingably attached to the link member 35a of the moving cowl 25.

The link mechanism 35 includes link members 35a, 3a.
5b, the block door 34 is positioned at the normal position F of the cowl 25 at a position where the fan outlet is fully opened,
Block door 34 at reverse position R of cowl 25
To position the fan outlet fully closed.

According to the above-described structure of the present invention, by swinging the swing flaps 22 around the shaft 21 in synchronization with each other by the swing device 24, the trailing edge of the swing flap 22 and the core cowl 17 are moved. It is possible to change the nozzle area of the fan nozzles arranged in between.

When the swing flap 22 swings with respect to the fixed flap 23 to increase the nozzle area, the fan outlet becomes uneven, and this unevenness promotes mixing of the fan flow and the external flow. As a result, fan noise due to the fan flow can be effectively reduced.

Furthermore, the drive rod 27a of the linear actuator 27 can be moved in the axial direction to operate the link mechanism 26 provided in the cowl 25 to swing the swing flaps in synchronization. Further, the stopper 28 can mechanically limit the movement of the swing flap beyond the swing range.

The movable cowl 25, which is movable from the normal position F adjacent to the fan nacelle 16 to the reverse position R on the downstream side along the axis Z, is attached to the drive rod 27a.
The oscillating flap can be oscillated within its oscillating range while being urged and held toward the fan nacelle by the compression spring 29 whose one end is supported by.

Further, when the linear actuator 27 is operated while the swing flap exceeds its swing range and cannot be mechanically moved by the stopper 28, the stroke of the cowl 25 causes the cowl 25 to move from the normal position F to the reverse position R on the downstream side. And the thrust reversing mechanism 30 interlocked with this can be operated.

At the normal position F of the cowl 25, the cascade 32 is covered with the cascade cover 33, the block door 34 is positioned by the link mechanism 35 at a position where the fan outlet is fully opened, and the bypass air is exhausted rearward from the fan outlet. it can. When the cowl 25 moves to the reverse position R, the cascade cover 3 fixed to the moving cowl 3
3 also moves backwards, exposing the cascade 32. At the same time, the block door 34 is positioned at the position where the fan outlet is fully closed by the link mechanism 35, and the bypass air can be guided to the outside upstream side through the cascade 32 to perform the reverse operation.

FIG. 4 is a diagram showing the operating characteristics of the variable fan nozzle device according to the present invention. In this figure, (A)
Is the pressure-flow rate characteristics of a conventional fan that does not have a variable mechanism,
(B) shows the pressure-flow rate characteristics of the fan of the present invention having a variable mechanism.

In FIG. 4 (A), the contour lines in the figure are fan efficiency contour lines, and the two circles show the operating point during takeoff and landing and the operating point during cruise. In the past, in order to prevent a surge during takeoff and landing, the fan nozzle had to be set slightly wider, and as a result, the fuel efficiency deteriorated because it deviated from the maximum efficiency point.

On the other hand, in the present invention of FIG. 4 (B), the fan nozzle is opened to the maximum efficiency point side during takeoff and landing, and closed to the maximum efficiency point side during cruising, so that operation at the maximum efficiency point of fan is always performed. It will be possible. Therefore, it is possible to achieve both (1) improved fuel efficiency during cruising and (2) increased thrust during takeoff and landing.

At the time of takeoff and landing, as shown in FIG. 4 (B), the pressure decreases, the flow rate increases and the apparent volume increases, but since the fan nozzle is wide, the exhaust speed is reduced while maintaining thrust. (3) Airport noise is reduced.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0047]

As described above, the variable fan nozzle device of the present invention has the following features. (1) By making the edge portion of the fan outlet uneven to promote mixing of the fan flow and the external flow, it is possible to reduce jet noise due to the fan flow. (2) When the moving cowl is closed, there is no change from the original shape of the fixed nozzle (nacelle), so there is no increase in external resistance.

Therefore, the variable fan nozzle device of the present invention (1) has a high effect of promoting the mixing of the fan flow and the external flow when the nozzle area is increased, and can effectively reduce the fan noise. , (2) External resistance can be minimized when the nozzle area is reduced,
(3) The thrust reversal actuator alone has the excellent effect of being able to drive both the thrust reverser and the variable fan nozzle at any time.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a variable fan nozzle device according to the present invention in a cruise state.

FIG. 2 is a configuration diagram of a variable fan nozzle device according to the present invention during takeoff and landing.

FIG. 3 is a configuration diagram of a variable fan nozzle device according to the present invention when a reverser is used.

FIG. 4 is a diagram showing operating characteristics of a variable fan nozzle device according to the present invention.

FIG. 5 is a configuration diagram of a conventional variable fan nozzle device.

[Explanation of symbols]

1 gas turbine engine, 2 core engine, 3 fan, 4 central axis, 5 annular nacelle, 6 outer nacelle,
7 upstream part, 8 downstream part, 9 core cowl, 10
Duct, 11 exhaust nozzle, 12 outer nacelle trailing edge, 13 displacement sleeve, 14 thrust reverser actuator, 15 displacement sleeve actuator, 16
Fan nacelle, 17 core cowl, 20 variable fan nozzle device, 21 swing shaft, 22 swing flap, 23
Fixed flap, 24 Swing device, 25 cowl (moving cowl), 26 Link mechanism, 27 Linear actuator, 27a Drive rod, 27b Collar member, 28 Stopper, 29 Compression spring, 30 Thrust reversing mechanism, 32
Cascade, 32 Cascade cover, 34 Block door, 35 Link mechanism, 36 Actuator position sensor, 37 Computing machine, 38 Fan state quantity sensor

Claims (6)

[Claims] 1. A plurality of swing flaps (2) swingable about an axis (21) provided at a fan outlet of a turbofan engine and having a front edge circumscribing a circle centered on an engine axis Z.
2. A variable fan nozzle device comprising: 2) and an oscillating device (24) for oscillating the plurality of oscillating flaps around the shaft in synchronization. 2. A plurality of fixed flaps (23) provided at a fan outlet of a turbofan engine, wherein the fixed flaps and the swing flaps are alternately arranged in a circumferential direction along the fan outlet. Claim 1 characterized by the above.
The variable fan nozzle device according to 1. 3. The rocking device (24) comprises the shaft (2).
1) A cowl (25) that swingably supports, a link mechanism (26) that is provided in the cowl and that swings a swing flap in synchronization, and a drive rod (27a) that moves in the axial direction. The variable fan nozzle device according to claim 1 or 2, further comprising: a linear motion actuator (27) for operating the link mechanism by means of a stopper, and a stopper (28) for limiting a swing range of a swing flap. . 4. The cowl (25) is a movable cowl movable from a normal position F located adjacent to a fan nacelle (16) of a turbofan engine to a downstream reverse position R along an axis Z. The linear actuator (27) is attached to the fan nacelle (16), the drive rod (27a) extends from the fan nacelle into the moving cowl, and one end is supported by the drive rod (27a). The variable fan nozzle device according to claim 3, further comprising a compression spring (29) for urging the moving cowl toward the fan nacelle in a swing range of the swing flap. 5. The linear motion actuator (27) has a stroke exceeding a swing range of the swing flap,
The link mechanism is operated within the swing range of the swing flap, and the cowl (25) is moved by a stroke exceeding the swing range.
5. The variable fan nozzle device according to claim 4, wherein is moved from the normal position F to the reverse position R to the downstream side, and the thrust reverser mechanism (30) interlocked therewith is operated. 6. The thrust reversing mechanism (30) is fixed to the fan nacelle (16) and guides a fan flow to the outside upstream side, and a cascade (32) is fixed to a moving cowl and the cascade (32) is in a normal position F. 32), a cascade cover (33), a block door (34) swingably attached to the moving cowl, and a normal position F of the cowl, where the block door is positioned so as to fully open the fan outlet. 6. A link mechanism (35) for positioning the block door in the reverse position R at a position where the fan outlet is fully closed.
The variable fan nozzle device according to 1.