JP2651396B2 - Variable jet nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable jet nozzle of a jet engine.

[0002]

2. Description of the Related Art FIG. 12 shows a relationship between a nozzle of an aircraft equipped with a conventional jet engine and an airframe. The engine is mounted below the fuselage or wing of the fuselage, and the nozzles occupy the rear half of the engine.

[0003] In an engine for an aircraft, a high-temperature and high-pressure combustion gas generated in a part called a gas generator part in the first half is ejected backward to obtain a thrust for traveling forward. The nozzle is an organ for converting high-temperature and high-pressure energy of the gas into kinetic energy by expanding the gas.

[0004] However, the optimum value of the expansion ratio varies depending on the flight Mach number of the airframe. In particular, the Mach number is 0 to 5 for a hypersonic aircraft, which is much larger than the Mach number of 0 to 1 for a normal passenger aircraft. Changes are needed. Therefore, a variable nozzle is indispensable to always keep the nozzle expansion ratio at the optimum.

Conventionally, a two-dimensional nozzle as shown in FIG. 13 has been used in a supersonic aircraft in order to change the expansion ratio of the nozzle.

It is common sense to convert pressure energy into kinetic energy by reducing the area of the nozzle outlet, and nozzles are used within the range of common sense in engines for subsonic aircraft. However, due to the special properties of the gas, the speed of the exhaust jet cannot be increased above Mach 1 simply by reducing the exit area. In order to obtain the speed of the exhaust jet required for a supersonic aircraft, it is necessary to narrow the gas passage area once (throat in FIG. 13) and then expand and exhaust again. This principle is known as the Laval tube principle.

[0007] Supersonic aircraft cruise at supersonic speeds.
0 before and after takeoff and landing, or when flying over land
In addition, it is necessary to fly at subsonic speed, and it is necessary to balance nozzle shapes with each other.

A two-dimensional variable nozzle whose principle is shown in FIG. 13 is used for that purpose. The nozzle is composed of fixed side walls (left and right) and movable flaps 21 and 22 (each up and down).
As a result, the flap 22 is connected to the flap 21 by a hinge 24.

The flaps 21 and 22 are rotated around the hinges 23 and 24 by various driving mechanisms, so that various shapes can be realized.

That is, in the supersonic state, the flap 21 is moved to the position shown in FIG. 13A to narrow the passage to the area shown as the throat, and then the flap 22 is opened to form the Laval tube. And get supersonic exhaust jet.

Further, in the subsonic state, as shown in FIG. 13 (b), the passage is narrowed down by the flaps 21 and 22 so that the air is exhausted as it is after being narrowed to the optimum throat area at the nozzle outlet. The flap is positioned for optimal exhaust jet velocity.

[0012]

The above-mentioned conventional variable jet nozzle has the following problems to be solved.

That is, although the conventional variable jet nozzle shown in FIG. 13, that is, the supersonic nozzle, can be used in principle up to hypersonic speed, it has a very large expansion ratio. The area of the portion indicated by "throat" becomes very small.

That is, in the case of a conventional two-dimensional nozzle, since the distance between the side walls is constant, the area ratio must be adjusted by moving only the upper and lower flaps 21 and 22, resulting in a very elongated throat shape. There have been problems such as the loss of the flap and the exhaust jet due to the mass and an increase in the amount of heat transfer.

An object of the present invention is to provide a variable jet nozzle in which not only the upper and lower flaps but also the side walls are movable to solve the above-mentioned problems.

[0016]

According to the present invention, as a means for solving the above-mentioned problems, the cross-sectional area of the exhaust gas passage is enlarged and reduced to change the ratio of the cross-sectional area to the cross-sectional area of the open end, thereby changing the injection speed of the exhaust gas. In the variable jet nozzle that obtains the speed of
A required portion is provided so as to be movable toward the center of the exhaust gas passage, and flaps forming upper and lower wall surfaces of the exhaust gas passage, and a required portion is provided so as to be movable toward the center of the exhaust gas passage and both sides of the exhaust gas passage. It is an object of the present invention to provide a variable jet nozzle having a movable side wall forming a wall surface.

[0017]

The present invention is configured as described above and has the following effects.

That is, not only the flaps forming the upper and lower wall surfaces of the exhaust gas passage but also the side walls forming both side walls are movable, and any structure is provided so that a desired portion can move toward the center of the exhaust gas passage. The cross-sectional area of the gas passage, ie, the cross-sectional shape of the throat portion, can be made substantially square. As a result, the outer peripheral line length / cross-sectional area of the cross section is much smaller than that of the conventional slit shape, so that the exhaust gas (exhaust jet) and the outer peripheral line, that is, the wall surface of the exhaust gas passage (flap and movable side wall) And the friction with energy is significantly reduced, and the friction loss and heat transfer loss of energy are significantly reduced.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIGS. 1A and 1B are schematic diagrams of the present embodiment, wherein FIG. 1A shows a state of a subsonic nozzle, FIG.
(C) is a perspective view showing the state of the hypersonic nozzle, respectively.
(D) is a cross-sectional view taken perpendicularly to the jet flow (exhaust gas flow) at the position of the throat 01 in (a) and viewed in the upstream direction,
(E) is a sectional view of (b), and (f) is (c) of FIG.
FIG.

FIG. 2 is a slightly detailed example of FIG.
(C) is an enlarged view, FIG. 3 is a detailed view of the flaps 1 and 2 of the present embodiment shown in FIG. 1, FIG. 4 is a detailed view of the movable side walls 3 and 4, and FIG. FIG. 6 is a detailed view of the side wall 6, and FIG. 7 is a detailed view of the horizontal wall 5, the upper flaps 1, 2 and the upstream in FIG. FIG. 8 is a perspective view showing a cross section from which the left side wall 6 and the left movable side walls 3 and 4 are also removed. FIG. 8 is a view of a subsonic state shown in each section of FIG. 7, and FIG. FIG. 9A is a view taken in the direction of the arrow A, FIG.
FIG. 10 is a diagram of the supersonic state shown in the same cross section as FIG. 10, and FIG. 11 is a view of the same in the hypersonic state, and FIGS. The detailed view including the drive mechanism shown, (c) shows the enclosure C of (a),
(D) is the perspective view which expanded and showed enclosure D of (b), respectively.

In the following description, the upstream and downstream sides refer to the upstream and downstream sides of the jet stream (exhaust gas stream), and the left and right refer to the left and right sides toward the upstream side of the jet stream.

In these figures, particularly FIGS. 1 and 11, reference numeral 1 designates upper and lower walls of the exhaust gas passage (however, only the lower side is shown in FIG. 11) and is connected to the flap 2 by a hinge 8 and The connecting portion is an upstream flap that is rotatable toward the center of the exhaust gas passage, and the upstream is rotatably supported by the hinge 7 on the engine case. Reference numeral 2 designates a lower flap which also forms upper and lower wall surfaces of the exhaust gas passage and is connected to the flap 1 by a hinge 8 and is movable to the center of the exhaust gas passage together with the flap 1. As shown in FIG. 11D, the pin 9 is slidably fitted in the groove 10 provided, and slides in the direction of the exhaust gas flow when the hinge 8 moves toward the center of the exhaust gas passage. Note that the flaps 1 and 2 are vertically symmetrical with respect to the nozzle axis, and a pair of flaps 1 and 2 are also mounted on the upper side. Reference numeral 3 denotes the left and right sides of the exhaust gas passage (only the right side is shown in FIG. 11), and a portion connected to the movable side wall 4 by a slide hinge can be moved by rotation toward the center of the exhaust gas passage. The movable side wall on the upstream side is rotatably supported by the hinge 11 on the upstream side by the hinge 11 on the engine case (or the side wall 6). Reference numeral 4 denotes a downstream movable side wall which can be connected to the movable side wall 3 by rotation in the direction of the center of the exhaust gas passage, and the downstream side is pivotally supported by the side wall 6 by a hinge 12. As shown in FIG. 11C, the movable side walls 3 and 4 are connected by a slide pin that slides by fitting a pin 13 fixed to the movable side wall 3 into a groove 14 formed in the movable side wall 4. . Reference numeral 5 denotes a horizontal wall outside the upper and lower flaps 1 and 2, which protects the flaps 1 and 2 and forms a fairing for an air flow flowing outside.
With the hinge 7 on the engine case side,
In response to the rotation of the flap 1. Numeral 6 extends left and right from the engine case side to the downstream side to cover and protect the outside of the movable side walls 3 and 4 while maintaining the rigidity of the nozzle portion, and the air flow fairing flowing outside. Side walls forming a ring, 7 and 8 are the hinges described above, 9 is the pin described above,
10 is a groove, 11 and 12 are each hinge, 13 is a pin, and 14 is a groove. 15 is a linear actuator for rotating the horizontal wall 5 around the hinge 7;
6 is a linear actuator for rotating the flap 1 around the hinge 7, and 17 is a linear actuator for rotating the movable side wall 3 around the hinge 11.

FIGS. 3 to 6 show the flaps 1 and 2 as described above.
2, showing the shapes of the movable side walls 3, 4, the horizontal wall 5, and the side wall 6 as an example, FIG. 3 is an exploded view showing the flaps 1, 2 separated by hinges 8, and FIG. , (B) is a side view, FIG. 4 is an exploded view showing the movable side walls 3, 4 separated by a slide hinge part, (a) is a plan view, (b) is a side view,
FIGS. 5A and 5B are views of the horizontal wall 5, wherein FIG. 5A is a plan view, FIG. 5B is a side view, FIG. 6 is a view of the side wall 6, FIG. 5A is a plan view, and FIG.

Next, the operation of the above configuration will be described.

First, in the range from subsonic speed to supersonic speed of about Mach 3, the operation, that is, the operation, is not particularly different from the conventional example, and is shown in FIGS. 1 (a), 1 (b), 8 and 9. As described above, the movable side walls 3 and 4 are in a state of being stuck to the inner side of the side wall 6, and perform an operation equivalent to the side wall (FIG. 13) of the conventional two-dimensional nozzle. Then, only the flaps 1 and 2 project from the hinge 8, which is the connecting portion thereof, toward the center of the exhaust gas flow. That is, while the linear actuator 17 is stopped, the linear actuators 15 and 16 operate to operate the flap 1.
And, the horizontal wall 5 is rotated toward the center of the exhaust gas flow. The flap 2 is responsive thereto via a hinge 8.

The pair of upper and lower hinges 8 is a portion that minimizes the cross-sectional area of the exhaust gas flow path, that is, the throat 0
1 is adjusted appropriately to obtain a desired flow rate.

Next, in order to create a hypersonic state at a higher speed, the flaps 1 and 2 which have protruded to the supersonic state of about Mach 3 are maintained as they are, and the linear actuator 17 is operated. Then, the movable side walls 3 and 4 are made to project toward the center of the exhaust gas passage. This state, that is, the hypersonic state (hypersonic nozzle state) is shown in FIG. 1 (c), (f) and FIG. When returning to the original state, the reverse operation is performed.

As described above, according to the present embodiment, when a hypersonic state is created, the movable side walls 3
Also, the cross-sectional shape of the throat 01 can be made close to square,
In comparison with the conventional case where the throat 01 is narrowed in a slit shape only by the upper and lower flaps, the outer peripheral line length of the throat 01 /
The cross-sectional area becomes much smaller and the exhaust jet (exhaust gas)
This has the advantage that the friction loss and the heat transfer loss are significantly reduced. This naturally improves fuel economy.

[0030]

The present invention has the following effects because it is configured as described above.

That is, according to the present invention, the friction area between the exhaust gas (jet stream) and the exhaust gas passage wall surface is reduced.
Low energy loss, increased thrust, and improved fuel economy when used as a gas turbine engine nozzle.

[Brief description of the drawings]

1A and 1B are schematic diagrams of one embodiment of the present invention, wherein FIG. 1A shows a state of a subsonic nozzle, FIG. 1B shows a state of a supersonic nozzle, and FIG.
Is a perspective view showing the state of the hypersonic nozzle, respectively, (d)
Is a cross-sectional view perpendicular to the jet flow (exhaust gas flow) cut at the throat 01 part of (a) and viewed in the upstream direction, (e) is a cross-sectional view of (b), and (f) is (c) ) Cross section,

FIG. 2 is an enlarged view of FIG. 1C of the embodiment,

FIG. 3 is a detailed view of the flaps 1 and 2 of the embodiment,

FIG. 4 is a detailed view of movable side walls 3 and 4 of the embodiment,

FIG. 5 is a detailed view of the horizontal wall 5 of the embodiment,

FIG. 6 is a detailed view of the side wall 6 of the embodiment,

FIG. 7 is a perspective view showing a cross section of FIG. 2 from which the upper horizontal wall 5, the upper flaps 1, 2 and the upstream left side wall 6, and the left movable side walls 3, 4 are removed. Figure,

8A and 8B are diagrams of the subsonic state shown in each section of FIG. 7 of the above embodiment, where FIG. 8A is a view as viewed from an arrow A of FIG. 7, FIG.

FIG. 9 is a diagram of a supersonic state shown in the same cross section as FIG. 8 of the embodiment,

FIG. 10 is a diagram of the hypersonic state shown in the same cross section as FIG. 8 of the above embodiment,

FIG. 11 is a detailed view including a drive mechanism, showing a cross section similar to FIG. 8 of the above-mentioned embodiment, slightly extending to the upstream side of the jet flow,

FIG. 12 is a longitudinal sectional view showing a relationship between a nozzle of an aircraft equipped with a conventional jet engine and an airframe.

FIG. 13 is a schematic perspective view of a conventional two-dimensional variable jet nozzle, in which (a) shows a supersonic state and (b) shows a subsonic state.

[Explanation of symbols]

 1, 2 flap 3, 4 movable side wall 5 horizontal wall 6 side wall 7, 8 hinge 9 pin 10 groove 11, 12 hinge 13 pin 14 groove 15, 16, 17 linear actuator

Claims (1)

(57) [Claims] 1. A variable jet nozzle for obtaining a desired speed by changing the ratio of the cross-sectional area of an exhaust gas passage to the cross-sectional area of an open end to change a jet speed of the exhaust gas, wherein a required portion is an exhaust gas. A flap movably provided in the center direction of the passage and forming upper and lower wall surfaces of the exhaust gas passage, and a movable side wall provided with a required portion movably in the center direction of the exhaust gas passage and forming wall surfaces on both sides of the exhaust gas passage. A variable jet nozzle characterized by comprising: