JP3219175B2 - Exhaust nozzle for supersonic aircraft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supersonic aircraft engine, and more particularly to a supersonic aircraft exhaust nozzle.

[0002]

2. Description of the Related Art In supersonic passenger aircraft (SST) having a flight speed exceeding Mach 1, noise due to jet jet has conventionally been a problem. FIG.
(A) is an engine exhaust nozzle of a Concorde machine developed in France, where the upper half shows supersonic speed and the lower half shows noise reduction. The exhaust nozzle includes a primary variable nozzle 52 that controls a high-speed gas flow from an after burner 51 of a jet engine, and a secondary variable nozzle 53 that mixes air into the high-speed gas flow and jets backward. ,
At the time of noise reduction (during takeoff / landing or subsonic velocities), outside air is introduced into the secondary variable nozzle, and the high speed gas flow from the primary variable nozzle and the low speed air are mixed by the mixer 54 to reduce the speed of the jet jet, At supersonic speeds, the introduction of outside air was stopped, the mixer was housed, and the jet stream was ejected as it was.

[0003]

However, in such a conventional exhaust nozzle, there is a problem that the performance of the mixer 54 is low and noise cannot be sufficiently reduced. That is, in the conventional exhaust nozzle, since the mixer needs to be housed by a simple link mechanism, the shape and size of the mixer are severely restricted, and only a mixer having a low performance like a flat plate can be housed.

On the other hand, in a subsonic jet engine,
An exhaust nozzle provided with a lobe-type mixer 55 shown in FIG. 4B is conventionally known. This lobe type mixer is
The partition walls 56 of the core flow and the bypass flow alternately enter in the circumferential direction at the junction 57 (this portion is called penetration), and the core flow and the bypass flow alternately located in the circumferential direction at the junction 57 merge. Therefore, there is a feature that the mixing efficiency is high. However, the lobe-type mixer 55 has an annular fixed form as a whole and is large in size, so that it cannot be applied to an SST in which storage is essential at supersonic speed.

The present invention has been made to solve the above-mentioned problems. That is, an object of the present invention is to provide an exhaust nozzle for a supersonic aircraft that is capable of storing a lobe type mixer having high mixing efficiency. It is another object of the present invention to provide a supersonic aircraft exhaust nozzle that can smoothly transition from a noise reduction mode at takeoff to a supersonic cruise mode through subsonic speed.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a transition duct connected to the rear of a core engine and having a cross-sectional shape varying from circular to rectangular, a side wall extending vertically to both rear sides of the core engine, and a core. A pair of first flaps A, which are provided at the upper and lower portions of the engine and are provided at an upstream end and which can swing around a first horizontal axis, and a pair of first flaps A which are located at the rear of the transition duct and are provided at an upstream end thereof. A pair of swingable second flaps B, a pair of lobe-shaped mixers M which are mounted on the third horizontal axis at the downstream end of the first flap A and which are horizontally deployed, A pair of third flaps C swingable about four horizontal axes, the mixer M has a fifth horizontal axis, and the fifth horizontal axis is connected to the fourth horizontal axis via a link; The fourth horizontal axis is located downstream of the side wall. Are movable along a spread guide, low noise exhaust nozzle for supersonic transport is provided, characterized in that.

According to a preferred embodiment of the present invention,
In the noise reduction state, the downstream end of the first flap A
In contact with the downstream end of the flap B, the third flap C moves to the most downstream side of the guide to form upper and lower walls of a mixer ejector that mixes an outside air flow and an engine flow, and a nozzle throat is formed at an outlet of the mixer M. Then, the first flap A rotates outward away from the second flap B, and the mixer moves to the outside in conjunction therewith, and further the first flap A
Moves and stops at the position where it coincides with the nozzle outer shape. Then, while the first flap A is fixed, the third flap C moves upstream along the side wall guide, and the mixer M is further stored by the link. Then, the third flap C stops at the upstream end of the guide, and again the first flap A starts moving inward and stops again when the downstream end of the first flap A contacts the outside of the third flap C,
The throat area is changed by the second flap B, and the third flap C is rotated in accordance with the nozzle pressure ratio, and a supersonic cruising state is established.

[0008]

The exhaust nozzle for a supersonic aircraft according to the present invention has a pair of lobe type mixers M which are linearly and horizontally developed.
The mixer M has an upstream end connected to the downstream end of the first flap A, and is connected to a fourth horizontal axis via a fifth horizontal axis and a link provided thereon. Therefore, the mixer M can be stored by rotating the first flap A and moving the fourth horizontal axis. Therefore, a lobe-type mixer with high mixing efficiency can be provided so as to be retractable, and outside air is introduced when noise is reduced, and the high-speed gas flow of the core engine and the outside air are efficiently mixed by the mixer to reduce the speed of the jet jet, Noise that is proportional to the eighth power of the exhaust speed of the jet can be reduced. Also, by stopping the introduction of outside air during supersonic cruising and storing the mixer outside the high-speed gas flow, each flap can be arranged optimally for supersonic flight.

In the noise reduction mode, the downstream end of the first flap A is in contact with the downstream end of the second flap B, and the third flap C moves to the most downstream side of the guide to mix the external air flow and the engine flow. A nozzle throat is formed at the outlet of the mixer M, and then the rotation of the first flap A and the third flap C
, The mixer M is retracted by the link mechanism, the first flap A starts to move inward again, stops when the downstream end of the first flap A contacts the outside of the third flap C, and the second flap B throats. By changing the area, the third flap C is rotated according to the nozzle pressure ratio, and the state can be shifted to the supersonic cruising state. Thereby, it is possible to smoothly transition from the noise reduction mode at takeoff to the supersonic cruise mode via the subsonic time.

[0010]

Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common portions are denoted by the same reference numerals. FIG. 1 is an overall sectional view of an exhaust nozzle for a supersonic aircraft according to the present invention. In this figure, the upper half shows a noise reduction mode at takeoff, and the lower half shows a supersonic cruising mode. In the noise reduction mode (upper half),
The outside air is introduced and mixed with the high-speed gas flow to reduce the speed of the jet jet. In the supersonic cruise mode (lower half), there is no outside air, the mixer is retracted, and each flap is supersonic It is an optimal arrangement for flight. Less than,
The exhaust nozzle in the noise reduction mode is called a mixer ejector nozzle.

Referring to FIG. 1, a supersonic aircraft exhaust nozzle according to the present invention includes a transition duct 18 connected to the rear of a core engine 16 and having a cross-sectional shape that changes from circular to rectangular. An extended side wall 20, a pair of first flaps A located at upper and lower portions of the core engine 16 and provided at an upstream end and capable of swinging around a first horizontal axis 1, and an upstream end located behind the transition duct 18. And a pair of second flaps B that can swing around the second horizontal axis 2 and a pair of upstream ends that are pivotally connected to the third horizontal axis 3 at the downstream end of the first flap A and that are developed linearly and horizontally. And a pair of third flaps C provided at the upstream end and capable of swinging around a fourth horizontal shaft 4. The mixer M has a fifth horizontal axis 5, which is connected to the fourth horizontal axis 4 via a link 24, and which extends to the downstream side provided on the side wall 20. The guide 11 is provided so as to be movable along the guide 11.

In FIG. 1, the apparatus of the present invention is a so-called two-dimensional nozzle having a constant cross-sectional shape in a direction transverse to the propulsion direction. The rear end of the core engine 16 is circular, while the rear end of the transition duct 18 is rectangular. That is, the cross-sectional shape of the transition duct 18 has changed from a circle to a rectangle. The transition duct shape is a straight wall, but may be a curved wall.

The first flap A functions as an external flap (upstream side) during supersonic cruising (lower half in FIG. 1), and as an ejector intake clamp for introducing outside air during noise reduction (upper half in FIG. 1). Function. The first flap A has an engine axis Z around a first horizontal axis 1 provided on the side wall 20.
Can be rotated in an angle range from 0 ° to about 40 °. This drive is performed by an actuator independent of other flaps.

The mixer M is obtained by developing the lobe-type mixer 55 shown in FIG. 4B in a linear and horizontal manner, and has a penetration that alternately enters the vertical direction in FIG. Thereby, at the time of noise reduction (upper half in FIG. 1), outside air can be introduced and efficiently mixed with the high-speed gas flow from the transition duct 18 to reduce the speed of the jet jet. The upstream end of the mixer M is connected to the downstream end of the first flap A by a horizontal shaft 3.
It is designed to be able to rotate from 360 ° to 360 °. Further, it is connected to the fourth horizontal shaft 4 via a link 24 and a horizontal shaft 5 provided near the upper end of the mixer M. The rotation and movement of the mixer M are performed by the actuator of the first flap A in conjunction with the change in the angle of the first flap A. 4th horizontal axis 4
Can be translated by an independent actuator along a guide 11 provided on the side wall 20.

The second flap B functions as a convergent flap for controlling a high-speed gas flow from the core engine 16 during supersonic cruising. The second flap B is about 12 degrees from the engine axis Z about the horizontal axis 2 of the nozzle side wall 20.
It is rotatably provided by an actuator independent of other flaps in an angle range of ° to 45 °.

The third flap C is an external flap, and also functions as a divergent flap for controlling the jet flow during supersonic cruising, and also functions as a mixing duct for introducing outside air when reducing noise. The third flap C is at 0 ° around the fourth horizontal axis 4 with respect to the engine Z axis.
It can be rotated by an actuator independent of other flaps in an angle range of about 17 °.

Each of the above-mentioned flaps A, B, C, mixer M
Are vertically interlocked with each other and are always positioned symmetrically with respect to the engine axis Z. Further, the third flap C
A sound-absorbing liner 25 is attached to the side of the passage and the side of the side wall 20 to reduce reflected sound. Also,
Appropriate seals are provided between each of the flaps A, B, and C, between the mixer M and the side wall 20, between the first flap A and the nacelle, between the second flap B and the transition duct, and between the first flap A and the mixer M. A mechanism is provided to minimize gas leakage. Also, as shown in FIG. 1, the downstream end of the first flap A (third horizontal axis 3) during supersonic cruise
However, the actuators are linked to each other so as to contact the outer surface of the third flap C.

FIGS. 2 and 3 are views showing the process from the noise reduction mode to the supersonic flight mode. Hereinafter, the operation of the exhaust nozzle of the present invention from the takeoff noise reduction mode to the supersonic flight mode will be described. FIG. 2A shows a noise reduction mode, which is used when the above-described mixer ejector nozzle is used. In this embodiment, the first flap A is the most angled, and the downstream end is in contact with the downstream end of the second flap B. The third flap C moves to the most downstream side (outward) of the guide 11, and forms upper and lower walls of a mixer ejector that mixes an outside air flow and an engine flow. In this form,
The nozzle throat is formed at the outlet of the mixer M.

Next, in FIG. 2B, first, the first flap A separates from the second flap B and starts rotating outward. In conjunction with this, the mixer moves to the outside. At this point, the nozzle throat is still formed at the outlet of the mixer M, but the amount of outside air introduced decreases. In FIG. 2C, the first flap A further moves. From this vicinity, the nozzle throat changes to a convergent portion by the second flap B, so that the second flap B is adjusted so that the throat area becomes constant. Further, in FIG. 2 (D), the first flap A stops where it coincides with the nozzle outer shape.

Next, in FIG. 3E, the first flap A
Is fixed, the third flap C moves upstream (inward) along the guide 11 on the side wall. Accordingly, the mixer M is further stored by the link 24. In FIG. 3 (F),
The third flap C stops at the upstream end of the guide 11. The mixer M is stored almost between the first flap A and the third flap C. Further, the first flap A starts moving inward again in FIG. Next, in FIG. 3 (H), the first flap A
Stops when the downstream end (third horizontal shaft 3) of the first contact portion contacts the outside of the third flap C. Thereafter, the second flap B changes the throat area according to the engine load, and the third flap C rotates according to the nozzle pressure ratio (NPR), so that the supersonic cruising mode (the lower half in FIG. 1) is achieved.

As described above, the exhaust nozzle for a supersonic aircraft of the present invention is a two-dimensional exhaust nozzle provided with a pair of lobe-shaped mixers M which are linearly and horizontally developed.
Has its upstream end connected to the downstream end of the first flap A,
Further, since the fifth horizontal axis provided thereon is connected to the fourth horizontal axis via a link, the mixer M can be stored by rotating the first flap A and moving the fourth horizontal axis. Therefore, a lobe-type mixer with high mixing efficiency can be provided so as to be retractable, and outside air is introduced when noise is reduced, and the high-speed gas flow of the core engine and the outside air are efficiently mixed by the mixer to reduce the speed of the jet jet, Noise that is proportional to the eighth power of the exhaust speed of the jet can be reduced. Also, by stopping the introduction of outside air during supersonic cruising and storing the mixer outside the high-speed gas flow, each flap can be arranged optimally for supersonic flight.

In the noise reduction mode, the downstream end of the first flap A is in contact with the downstream end of the second flap B, and the third flap C moves to the most downstream side of the guide to mix the external air flow and the engine flow. A nozzle throat is formed at the outlet of the mixer M, and then the rotation of the first flap A and the third flap C
, The mixer M is retracted by the link mechanism, the first flap A starts to move inward again, stops when the downstream end of the first flap A contacts the outside of the third flap C, and the second flap B throats. By changing the area, the third flap C is rotated according to the nozzle pressure ratio, and a transition to a supersonic cruise mode can be made. Thereby, it is possible to smoothly transition from the noise reduction mode at takeoff to the supersonic cruise mode via the subsonic time.

It should be noted that the present invention is not limited to the above-described embodiment, but can be freely modified without departing from the gist of the present invention.

[0024]

As described above, the low-noise exhaust nozzle for a supersonic transport according to the present invention is provided with a lobe type mixer having a high mixing efficiency so as to be retractable, and is reduced from a noise reduction form at takeoff to a subsonic speed. It has an excellent effect of smoothly transitioning to a sound speed cruise mode.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of an exhaust nozzle for a supersonic aircraft according to the present invention.

FIG. 2 is a diagram showing a process from a noise reduction mode to a subsonic flight mode.

FIG. 3 is a diagram showing a process up to a supersonic flight mode following FIG. 2;

FIG. 4 is a schematic configuration diagram of a conventional exhaust nozzle.

[Explanation of symbols]

 A first flap B second flap C third flap M mixer Z engine axis 1-5 horizontal axis 11 guide 16 core engine 18 transition duct 20 side wall 24 link 25 sound absorbing liner 51 afterburner 52 primary variable nozzle 53 secondary variable nozzle 53 54 mixer 55 lobe type mixer 56 partition wall 57 junction

Continuation of front page (72) Inventor Takeshi Kashiwagi 229 Torogaya, Mizuho-cho, Nishitama-gun, Tokyo Ishikawa-jima-Harima Heavy Industries, Ltd. Mizuho Plant (56) References US Patent 5,150,052 (US, A) US Patent 3,583,973 (US, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) F02K 1/12 F02K 1/08 F02K 1/46

Claims (2)

(57) [Claims] 1. A transition duct connected to the rear of a core engine and having a cross-sectional shape that changes from circular to rectangular, a side wall extending perpendicularly to both rear sides of the core engine, and upper and lower portions of an upper and lower portion of the core engine at an upstream end. A pair of first flaps A provided so as to be able to swing around a first horizontal axis, and a pair of second flaps B provided behind the transition duct and provided at an upstream end and swingable around a second horizontal axis. When,
A pair of lobe-shaped mixers M whose upstream ends are pivotally connected to a third horizontal axis at the downstream end of the first flap A and are linearly and horizontally developed, and a pair of lobe-shaped mixers provided at the upstream end and capable of swinging around a fourth horizontal axis. The mixer M has a fifth horizontal axis, the fifth horizontal axis is connected to the fourth horizontal axis via a link, and the fourth horizontal axis is provided on the side wall. A low-noise exhaust nozzle for a supersonic transport, characterized in that the nozzle is movably provided along a guide extending downstream. 2. The first flap A in the noise reduction state.
Is in contact with the downstream end of the second flap B, the third flap C moves to the most downstream side of the guide, and forms upper and lower walls of a mixer ejector that mixes the outside air flow and the engine flow, and the nozzle throat is M, and then the first flap A rotates outward away from the second flap B, in conjunction with which the mixer moves outward,
Further, the first flap A moves and stops at a position where the first flap A coincides with the outer shape of the nozzle. Then, while the first flap A is fixed, the third flap C moves upstream along the side wall guide, and accordingly, the link The mixer M is further retracted, and then the third flap C stops at the upstream end of the guide, and again the first flap A starts moving inward, and the downstream end of the first flap A contacts the outside of the third flap C. 2. The supersonic cruise state according to claim 1, wherein the throat area is changed by the second flap B, and the third flap C is rotated in accordance with the nozzle pressure ratio to be in a supersonic cruise state. 3. Low noise exhaust nozzle for sonic transport.