JPH07208262A - Exhaust nozzle for supersonic aircraft - Google Patents

Abstract

PURPOSE:To provide an exhaust nozzle for a supersonic aircract which is provided with a mixer of lobe type with high mixing efficiency in a storable manner, and capable of smooth shifting from the noise-reduced mode at the take-off to the supersonic cruising mode through the subsonic mode. CONSTITUTION:An exhaust nozzle is provided with a transition duct having a sectional shape changing from the circular shape to the rectangular shape, a side wall 20 extending on each side rearward of a core engine, a pair of first flaps A swayable around the first horizontal shaft 1, a pair of second flaps B swayable around the second horizontal shaft 2, a pair of lobe type mixers M which are pivotably fitted to the third horizontal shaft 3 at the downstream end of the first flaps A and developed in a linearly horizontal direction, and a pair of third flaps C swayable around the fourth horizontal shaft 4. The mixers M have the fifth horizontal shaft 5, and this fifth horizontal shaft is connected to the fourth horizontal shaft 4 through a link 24, and the fourth horizontal shaft is provided in a movable manner along a guide 11 provided on the side wall.

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 a supersonic passenger aircraft (SST: Super Sonic Transporter) whose flight speed exceeds Mach 1, noise due to jet jet has been a problem. Figure 4
(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. This exhaust nozzle includes a primary variable nozzle 52 that controls the high-speed gas flow from the afterburner 51 of the jet engine, and a secondary variable nozzle 53 that mixes air into the high-speed gas flow and ejects it backward. ,
At the time of noise reduction (during takeoff / landing or at subsonic speed), the outside air is introduced into the secondary variable nozzle, and the mixer 54 mixes the high-speed gas flow and the low-speed air from the primary variable nozzle to reduce the speed of the jet jet. At supersonic speed, the introduction of outside air was stopped, the mixer was housed, and the jet jet 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 it is necessary to store the mixer with a simple link mechanism, there are severe restrictions on the shape and size of the mixer, and only a mixer with low performance such as a flat plate can be stored.

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

The present invention was created to solve the above problems. That is, an object of the present invention is to provide an exhaust nozzle for a supersonic aircraft, which is capable of storing a lobe mixer having high mixing efficiency. Another object of the present invention is to provide an exhaust nozzle for a supersonic aircraft that can smoothly shift from a noise reduction mode at takeoff to a supersonic cruise mode after a subsonic time.

[0006]

According to the present invention, a transition duct connected to the rear of a core engine and having a cross-sectional shape changing from a circular shape to a rectangular shape, side walls extending vertically on both rear sides of the core engine, and a core. A pair of first flaps A located at the upper and lower parts of the engine and swingable around a first horizontal axis provided at the upstream end, and a second flap A provided at the upstream end located behind the transition duct. A pair of swingable second flaps B, a pair of lobe-shaped mixers M that are horizontally deployed with their upstream ends pivotally attached to a third horizontal shaft at the downstream end of the first flap A, and a pair of first lobes provided at the upstream end. And a pair of third flaps C swingable around 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 the downstream provided on 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 is the second
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 the upper and lower walls of the mixer ejector for mixing the external air flow and the engine flow, and the nozzle throat is formed at the outlet of the mixer M. Then, the first flap A is separated from the second flap B and is rotated outward, and the mixer is moved to the outside in conjunction therewith, and the first flap A is further rotated.
Moves and stops at a position matching the outer shape of the nozzle, and then the third flap C moves upstream along the guide of the side wall while the first flap A is fixed, and accordingly, the mixer M is further stored by the link. Then, the third flap C stops at the upstream end of the guide, the first flap A starts moving inward again, and stops 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, the third flap C is rotated according to the nozzle pressure ratio, and the supersonic cruise state is set.

[0008]

The above-described supersonic aircraft exhaust nozzle of the present invention is provided with a pair of lobe-shaped mixers M that are linearly and horizontally deployed.
This mixer M is a three-dimensional exhaust nozzle, the upstream end of which is connected to the downstream end of the first flap A, and the fifth horizontal shaft provided on the mixer M and the fourth horizontal shaft which are connected to each other via a link. 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 that it can be stored, external air is introduced at the time of noise reduction, and the high-speed gas flow of the core engine and the external air are efficiently mixed by the mixer to reduce the speed of the jet jet, Noise proportional to the eighth power of the exhaust speed of the jet jet can be reduced. In addition, by stopping the introduction of outside air during supersonic cruise and storing the mixer outside the high-speed gas flow, each flap can be placed in an optimal arrangement for supersonic flight.

Further, in the noise reduction mode, the downstream end of the first flap A contacts 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 outside air flow and the engine flow. The upper and lower walls of the mixer ejector, the nozzle throat is formed at the outlet of the mixer M, then the rotation of the first flap A and the third flap C.
Of the mixer causes the link mechanism to store the mixer M, the first flap A starts moving inward again, and stops when the downstream end of the first flap A contacts the outside of the third flap C, and the second flap B causes the throat to move. By changing the area and rotating the third flap C according to the nozzle pressure ratio, it is possible to shift to the supersonic cruise state. As a result, it is possible to smoothly shift from the noise reduction mode at takeoff to the supersonic cruise mode after the subsonic time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment 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. 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 the noise reduction mode during takeoff and the lower half shows the supersonic cruise mode. In the noise reduction form (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 introduction of outside air, the mixer is stored, and each flap is supersonic. It has the best layout for flight. Less than,
The exhaust nozzle in the noise reduction mode is called a mixer ejector nozzle.

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

In FIG. 1, the device of the present invention is a so-called two-dimensional nozzle having a constant cross-sectional shape in the transverse direction with respect to the propelling direction. The rear end of the core engine 16 is circular, but the rear end of the transition duct 18 is rectangular. That is, the cross-sectional shape of the transition duct 18 changes from a circular shape to a rectangular shape. The transition duct shape is a straight wall, but it may be a curved wall.

The first flap A functions as an external flap (upstream side) during supersonic cruise (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 is provided around the first horizontal axis 1 provided on the side wall 20 around the engine axis Z.
Can be rotated in an angular range of 0 ° to about 40 °. This drive is performed by an actuator that is independent of the other flaps.

The mixer M is a linear horizontal expansion of the lobe mixer 55 shown in FIG. 4 (B), and has penetrations that alternate vertically in FIG. As a result, when noise is reduced (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 jet jet speed. The upstream end of the mixer M is connected to the downstream end of the first flap A by the horizontal shaft 3, and the mixer M has a vertical axis of 0.
It is possible to rotate from ° to 360 degrees. 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 moved in parallel by a separate actuator along a guide 11 provided on the side wall 20.

The second flap B functions as a convergent flap that controls the high velocity gas flow from the core engine 16 during supersonic cruise. The second flap B has a diameter of about 12 with respect to the engine axis Z around the horizontal axis 2 of the nozzle side wall 20.
It is rotatably provided by an actuator independent of other flaps within 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 jet during supersonic cruise and as a mixing duct for introducing outside air during noise reduction. The third flap C is 0 ° with respect to the engine Z axis around the fourth horizontal axis 4.
It can be rotated by an actuator independent of other flaps in an angular range of about 17 °.

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

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

Then, in FIG. 2B, first, the first flap A is separated from the second flap B and starts to rotate 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 the second flap B is adjusted so that the throat area becomes constant. Further, in FIG. 2 (D), the first flap A stops when it coincides with the outer shape of the nozzle.

Next, in FIG. 3 (E), the first flap A
The third flap C moves to the upstream side (inward) along the guide 11 on the side wall while fixing the. 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 mostly housed between the first flap A and the third flap C. Further, in FIG. 3G, the first flap A again starts moving inward. Next, in FIG. 3 (H), the first flap A
Stops at the downstream end (third horizontal axis 3) of the outer edge of the third flap C. After that, 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), resulting in a supersonic cruise mode (lower half of FIG. 1).

As described above, the exhaust nozzle for supersonic aircraft of the present invention is a two-dimensional exhaust nozzle provided with a pair of lobe-shaped mixers M that are linearly and horizontally developed.
Has its upstream end connected to the downstream end of the first flap A,
Further, since it is connected to the fourth horizontal shaft via a link with the fifth horizontal shaft provided thereon, the mixer M can be stored by rotating the first flap A and moving the fourth horizontal shaft. Therefore, a lobe-type mixer with high mixing efficiency can be provided so that it can be stored, external air is introduced at the time of noise reduction, and the high-speed gas flow of the core engine and the external air are efficiently mixed by the mixer to reduce the speed of the jet jet, Noise proportional to the eighth power of the exhaust speed of the jet jet can be reduced. In addition, by stopping the introduction of outside air during supersonic cruise and storing the mixer outside the high-speed gas flow, each flap can be placed in an optimal arrangement for supersonic flight.

Further, in the noise reduction mode, the downstream end of the first flap A contacts 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 outside air flow and the engine flow. The upper and lower walls of the mixer ejector, the nozzle throat is formed at the outlet of the mixer M, then the rotation of the first flap A and the third flap C.
Of the mixer causes the link mechanism to store the mixer M, the first flap A starts moving inward again, and stops when the downstream end of the first flap A contacts the outside of the third flap C, and the second flap B causes the throat to move. By changing the area and rotating the third flap C according to the nozzle pressure ratio, it is possible to shift to the supersonic cruise mode. As a result, it is possible to smoothly shift from the noise reduction mode at takeoff to the supersonic cruise mode after the subsonic time.

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

[0024]

As described above, the low-noise exhaust nozzle for supersonic transport aircraft of the present invention is provided with a lobe-type mixer capable of storing a high mixing efficiency so that it can be stored in a low noise state during take-off and after passing through subsonic speed. It has an excellent effect that it can smoothly transition to the sonic cruise mode.

[Brief description of drawings]

FIG. 1 is an overall cross-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 the supersonic flight mode following FIG.

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

[Explanation of symbols]

 A 1st flap B 2nd flap C 3rd 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 54 mixer 55 lobe type mixer 56 partition wall 57 confluence part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takeshi Kashiwagi 229 Tonogaya, Mizuho-cho, Nishitama-gun, Tokyo Ishikawajima Harima Heavy Industries Ltd. Mizuho factory

Claims (2)

[Claims] 1. A transition duct connected to the rear of the core engine and having a cross-sectional shape changing from a circular shape to a rectangular shape, side walls extending vertically to both rear sides of the core engine, and an upper end and a lower end of the core engine at an upstream end. A pair of first flaps A, which are swingable around a first horizontal axis, and a pair of second flaps B, which are located rearward of the transition duct and are swingable around a second horizontal axis provided at the upstream end. When,
A pair of lobe-shaped mixers M each of which has an upstream end pivotally attached to a third horizontal shaft at the downstream end of the first flap A and which is linearly developed horizontally, and a pair which is swingable around a fourth horizontal shaft provided at the upstream end. And a third flap C of the mixer M having a fifth horizontal axis, the fifth horizontal axis being connected to a fourth horizontal axis via a link, the fourth horizontal axis being provided on the side wall. A low noise exhaust nozzle for a supersonic transport aircraft, which is provided so as to be movable along a guide that spreads to the downstream side. 2. The first flap A in the noise reduction state.
Of the mixer 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 form the upper and lower walls of the mixer ejector for mixing the external air flow and the engine flow, and the nozzle throat is the mixer throat. Is formed at the outlet of M, then the first flap A rotates outwardly away from the second flap B, and in conjunction therewith, the mixer moves to the outside,
Further, the first flap A moves and stops at a position matching the outer shape of the nozzle. Then, while the first flap A is fixed, the third flap C moves upstream along the guide of the side wall. The mixer M is further retracted, then the third flap C stops at the upstream end of the guide, and again the first flap A starts moving inward, where the downstream end of the first flap A contacts the outside of the third flap C. 2. The super stop according to claim 1, wherein the throat area is changed by the second flap B and then the third flap C is rotated in accordance with the nozzle pressure ratio to enter a supersonic cruising state. Low noise exhaust nozzle for sonic transport aircraft.