JPH06200825A - Air intake structure of supersonic airplane - Google Patents

Abstract

PURPOSE:To secure a same entropy type compression area corresponding to the variation of the flight speed so as to improve the compressive efficiency of an engine intake air by forming a compression area by an impulse wave between a winding member and a cowl at the rear end of the front ramp, so as to compress the passing air and reduce the speed. CONSTITUTION:An air intake 10 is composed of the front ramp 11 and the rear ramp 6 provided to the rear side of the front ramp 11 by placing a throat slot air bleed clearance 5. At the lower side of both ramps 11 and 6, a cowl 7 is provided. To the front ramp 11, plural movable plates 4a, and a caterpillar (winding member) 11a are connected around a fluctuation axis 4c, the whole body is fluctuated by a hydraulic cylinder 9a, and the inclinations of them are changed each other by a hydraulic cylinder 9b. And the caterpillar 11a is wound on a movable idler 12 and arranged in a bending condition, and a hydraulic cylinder (pulling means) 15 is provided to its one end. In such a constitution, an adequate compression area can be formed by converting the form of the caterpillar 11a, and a formation of reflection wave by the impulse wave between the cowl 7 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air intake structure for a supersonic aircraft, and more particularly to a technique for obtaining optimum flight performance according to changes in flight speed in the supersonic range.

[0002]

2. Description of the Related Art In recent years, a turbofan engine has been used from a stationary state on the ground to a low Mach number as an engine used for an aircraft flying at a Mach number of 2.5 to 5, and ram combustion at a flight speed of Mach number of 3 or more. Cycle Engines that are designed to be used are being considered.

In the air intake (intake) used in this combined cycle engine, the shock wave generated during supersonic flight is used to efficiently compress the air taken into the engine and decelerate it to subsonic speed. Is done.

As a conventional intake used in a combined cycle engine, there is a structure shown in FIGS. 2 to 4. In the intake 1, the ceiling surface of the air intake passage 3 communicating with the engine 2 has a plurality of movable plates 4a, 4b.
Is formed by a front lamp 4 which is swingably connected to each other, and a rear lamp 6 which is arranged behind the front lamp 4 with a throat slot bleeding gap 5 therebetween. The cowl 7 that forms the bottom surface of the air intake passage 3 is disposed below the rear lamp 6.

In the example shown in FIG. 2, the front lamp 4 is
Three flat plate-shaped movable plates 4a arranged in series and one curved plate-shaped movable plate 4b arranged at the rear end thereof are parallel axes orthogonal to the longitudinal direction of the air intake passage 3. It is configured to be swingably connected around a center 4c (swing axis), and its front end is swingably connected to a machine body 8 arranged above. The front ramp 4 includes a hydraulic cylinder 9 arranged between the front ramp 4 and the body 8.
By a, it can be swung as a whole and the mutual inclination angle can be changed by the hydraulic cylinder 9b arranged between the movable plates 4a and 4b.

The rear lamp 6 has its rear end swingably connected to the machine body 8 and can be rocked around its rocking axis 6a by a hydraulic cylinder 9c arranged between the rear lamp 6 and the machine body 8. Has become.

The cowl 7 has a concave surface portion 7a and a sharpened portion 7a.
b, the shock wave generated in the lamp 4 is concentrated on the sharpened portion 7b.

The operation of the intake 1 thus constructed will be described below. First, at the time of take-off from a stationary state on the ground and during low-speed flight, all the hydraulic cylinders 9a, 9b, 9c are contracted, and the front ramp 4 and the rear ramp 6 are moved upward so that the cowl 7 The cross-sectional area of the air intake passage 3 formed therebetween is maximized so that a large amount of air is taken in.

Next, when the flight speed becomes high, for example, when the flight speed is about Mach number 2, as shown in FIG. 3, the hydraulic cylinders 9a, 9b and 9c are extended to extend the front ramp 4 and the rear ramp. 6 is lowered and the space between the cowl 7 is narrowed. In such a situation, oblique shock waves S ₁ and S ₂ are generated from the bent portion 4d formed at the boundary between the movable plates 4a of the front lamp 4. In the example shown in FIG. 3, the angle of the movable plate 4a is adjusted so that the oblique shock waves S ₁ and S ₂ are generated toward the sharp portion 7b of the cowl 7. In addition, a compression wave is generated from the concave surface portion 7a of the cowl 7 toward the curved plate-shaped movable plate 4b of the front lamp 4 arranged behind the cowl 7. Since the concave surface portion 7a and the movable plate 4b have a smooth shape without a bent portion, a fan-shaped area A (isentropic region) where innumerable compression waves are generated is formed between the concave surface portion 7a and the movable plate 4b. Area).

By the way, it is known that when air is passed through the oblique shock waves S ₁ and S ₂ , abrupt changes in velocity, pressure, density, temperature, etc. occur before and after it. And
The intake 1 has the role of compressing the air taken in from the front and reducing its speed.

Further, in the compression in the region A in which innumerable compression waves are arranged, such as the isentropic compression region A, it is known that the compression can be performed while suppressing the total pressure loss. ing. Therefore, the concave portion 7a of the cowl 7
Further, the shape of the movable plate 4b is such that the air flow compressed by passing through the isentropic compression region A is decelerated to a Mach number of about 1 before the tip position of the rear lamp 6 arranged behind it. It is designed and decelerated to a subsonic speed by the vertical shock wave S ₃ generated near the tip position of the rear lamp 6.

[0012]

When such an intake 1 is used and a higher-speed flight (for example, Mach number of about 5) is carried out, as shown in FIG. 4, each hydraulic cylinder 9a is used. 9b and 9c are further extended so that the front lamp 4 and the rear lamp 6 are close to the cowl 7 and the air intake passage 3 is narrowed. This is because as the flight speed increases, the compression ratio of the air compressed by the intake 1 and finally decelerated to about Mach number 1 increases.

However, in the conventional intake 1, the movable plate 4a which forms the above-mentioned isentropic compression area A by swinging the front ramp 4 and the rear ramp 6 according to the flight speed in this way. It is difficult to match the shapes of the concave portion 7a of the cowl 7 and the cowl 7. That is, the cowl 7 is formed so as to form the isentropic compression area A.
The curvature of the movable plate 4a, which is designed corresponding to the curvature of the concave surface portion 7a, must change with the change in the mutual gap between the cowl 7 and the movable plate 4a. With the conventional intake 1 that uses the single movable plate 4a over the range, it is difficult to secure an appropriate isentropic compression region A, and as a result, the compression wave is received in the front lamp 4 that receives the compression wave. However, there is a problem that the reflected wave or the expansion wave of the above-mentioned occurs and the compression efficiency is lowered.

The present invention has been made in view of the above-mentioned circumstances, and secures an appropriate isentropic compression region A corresponding to changes in flight speed, and has a high compression efficiency of air taken into the engine 2. It is intended to provide an air intake structure for a supersonic aircraft.

[0015]

In order to achieve the above object, the present invention enables a plurality of movable plates arranged in series to mutually swing about a swing axis perpendicular to the series direction. A front lamp connected to the front lamp, a rear lamp arranged behind the front lamp with a throat slot bleeding gap, and a cowl forming an air intake passage in a mutual gap between these lamps. Each of the movable plates and the rear lamp of the front lamp is provided with an angle changing means for changing a swing angle, and the front end of the front lamp forming one end of the throat slot extraction gap is provided with the front portion. A winding member is provided to extend the partial lamp, and the winding member has an axis parallel to the swing axis of the movable plate and is wound around an idler that is moved in a direction intersecting the axis. It is rotated and placed in a bent state, and its end Proposes an air intake structure of a supersonic aircraft is pulling means that applies tension to the winding times member is disposed.

[0016]

According to the air intake structure of the present invention, during supersonic flight, a compression region due to a shock wave is formed between the cowl and the winding member provided at the rear end of the front lamp, and the compression is performed. The air passing through the area will be compressed and decelerated. When the flight speed is changed, the angle changing means attached to each movable plate is operated to adjust the tilt angle of each movable plate forming the front lamp, the rear lamp and the front lamp. By actuating the pulling means and moving the idler in a direction intersecting the axis of the idler, the shape of the winding member wound around the idler is changed. As a result, it is possible to change the shape to form an appropriate compression region at the position of the winding member that is moved according to each flight speed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an air intake structure for a supersonic aircraft according to the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 10 is an intake (air intake), 11 is a front lamp, 11a is a movable plate (winding member), 11b is a surface sheet, 12 is an idler, 12a is an axial center, and 13 is a hydraulic cylinder ( Angle changing means), 14 is a swinging means, 15 is a hydraulic cylinder (pulling means), S ₁ , S ₂ , S ₃ are shock waves, A
Is an isentropic compression region. In this embodiment, the same parts as those of the conventional intake 1 shown in FIGS. 2 to 4 are designated by the same reference numerals to simplify the description.

Intake 10 (air intake) of this embodiment
Is a front lamp 11 in which a plurality of movable plates 4a are swingably connected to each other on a ceiling surface of an air intake passage 3 communicating with the engine 2, and a throat slot extraction gap is provided behind the front lamp 11. 5 is formed by a rear lamp 6 which is arranged with an empty space, and a cowl 7 which forms a bottom surface of the air intake passage 3 is arranged below the front lamp 11 and the rear lamp 6. In this respect, it is common with the conventional intake 1. However, the intake 10 of the present embodiment
Is different from the conventional intake 1 in the configuration of the front lamp 11.

The front lamp 11 includes three flat plate-shaped movable plates 4a arranged in series and a caterpillar-shaped movable plate 11a (winding member) arranged at the rear end of the front lamp 11. The passage 3 is swingably connected around a parallel axis 4c (swing axis) orthogonal to the longitudinal direction of the passage 3, and the front end is swingably connected to the machine body 8 arranged above. The front lamp 11 includes a hydraulic cylinder 9a arranged between the front lamp 11 and the body 8.
Thus, while being swung as a whole, mutual inclination angles can be changed by the hydraulic cylinders 9b arranged between the movable plates 4a.

The caterpillar-shaped movable plate 11a is wound around an idler 12 having an axis 12a arranged in parallel with the swing axis 4c. The idler 12
Is attached to the tip of a hydraulic cylinder 13 attached to the machine body 8. The hydraulic cylinder 13 can change its angle by a swinging means 14 such as a motor, whereby the idler 12 is rotated.
However, it can be arbitrarily moved two-dimensionally in the direction intersecting the axis 12a.

The movable plate 11a has one end connected to the movable plate 4a arranged in front of the movable plate 11a, the idler 12 is wound around the movable plate 11a, and the rear end thereof is bent upward to form a hydraulic pressure. It is connected to the machine body 8 via a cylinder 15. The hydraulic cylinder 15 is moved in synchronization with the hydraulic cylinder 13 that moves the idler 12, so that the position of the movable plate 11a can be changed while pulling the movable plate 11a. Furthermore, the movable plate 11a
On the surface of the air intake passage 3 side, a surface sheet 11b made of, for example, a thin metal plate is provided so as to cover the movable plate 11a, so as to keep the inner surface of the air intake passage 3 smooth. It has become.

A rear lamp 6 is provided behind the bent portion of the movable plate 11a with a throat slot bleeding gap 5 therebetween, and the size of the throat slot bleeding gap 5 is arbitrarily adjusted by the movement of the idler 12. Is able to.

According to the intake 10 constructed as described above, the hydraulic cylinders 9a, 9a
The pressure oil is sent to b9c, the inclination angles of the front lamp 11 and the rear lamp 6 are changed, and the inclination angles of the movable plates 4a are changed, so that the swing axis 4
Shock waves S ₁ and S ₂ generated from c are generated by the sharp portion 7 of the cowl 7.
It is set to go to b. At the same time, the hydraulic cylinder 13 of the idler 12 that winds the movable plate 11a in the form of a caterpillar and the hydraulic cylinder 15 that applies tension to the movable plate 11a are operated to move the position of the bent portion of the movable plate 11a. Hydraulic cylinder 1
By the tension applied from 5, the curvature of the movable plate 11a is changed, and an appropriate isentropic compression area A is formed between the cowl 7 and the concave surface portion 7a.

Further, the position of the shock wave S ₃ (vertical shock wave) at which the air passing through the isentropic compression region A reaches the Mach number 1 may move back and forth and may become unstable. 12 is moved in the front-rear direction to adjust the size of the throat slot bleeding gap 5 and the amount of air extracted from the throat slot bleeding gap 5 to adjust the position of the vertical shock wave S ₃ to the rear ramp. It is possible to keep the tip 6 at a stable position.

Thus, the air taken into the engine 2 can be efficiently compressed, and the speed of the air supplied to the engine 2 can be stably maintained in the subsonic state. As a result, the flight performance can be improved, the soundness of the engine 2 can be improved, and the like.

The following techniques can be adopted in the air intake structure of the supersonic aircraft of the present invention. Although the number of the idlers 12 is one, a plurality of idlers 12 are provided instead of the idlers 12, and the caterpillar-shaped movable plate 1 is provided.
Form the shape of 1a into an arbitrary shape. Instead of the caterpillar-shaped movable plate 11a, another winding member, for example, a belt-shaped member should be used. Although the hydraulic cylinders 9a, 9b, 13 and 15 are used as the angle changing means of the movable plates 4a, 11a, 5 and the like, any other actuator may be used.

[0027]

As described in detail above, the air intake structure for a supersonic aircraft according to the present invention includes a front lamp which is formed by connecting a plurality of movable plates so as to be swingable about a swing axis. It is equipped with a rear lamp that is arranged behind it with a throat slot bleeding gap, and a cowl that forms an air intake passage in the mutual gap between these lamps. Angle changing means for changing the moving angle are respectively provided, and a winding member is disposed at a rear end portion of the front lamp that forms one end of the throat slot extraction gap, and the winding member is wound around a movable idler. Since the pulling means that is turned to be in a bent state and has a tension applied to one end thereof is provided, the following effects are obtained. Since the shape of the winding member can be changed by the idler and the pulling means, by changing the shape of the winding member according to the flight speed, the shock wave and the compression wave formed between the cowl and the cowl can be changed. The air intake passage can be configured so as not to form a reflected wave at
Air compression efficiency can be improved and flight performance can be improved. By moving the idler and operating the tensioning means, it is possible to adjust the throat slot bleed gap size, so it is possible to stabilize the compressed air velocity supplied to the engine at all flight speeds and stabilize flight performance. At the same time, the soundness of the engine can be improved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of an air intake structure for a supersonic aircraft according to the present invention.

FIG. 2 is a conceptual diagram showing a conventional example of an air intake structure of a supersonic aircraft.

FIG. 3 is a conceptual diagram showing a state in which the flight speed in the air intake structure of FIG. 2 is about Mach number 2.

FIG. 4 is a conceptual diagram showing a state in which the flight speed in the air intake structure of FIG. 2 is about Mach number 5;

[Explanation of symbols]

 3 Air intake passage 4a Movable plate 4c Oscillating shaft center 5 Throat slot bleeding gap 6 Rear lamp 7 Cowl 9a, 9b Hydraulic cylinder (angle changing means) 11 Front lamp 11a Movable plate (winding member) 12 Idler 15 Hydraulic cylinder (Pulling means)

Claims (1)

[Claims] 1. A front lamp comprising a plurality of movable plates arranged in series connected to each other so as to be swingable around a swing axis orthogonal to the series direction, and a rear lamp behind the front lamp. The throat slot is provided with a rear lamp arranged with a bleeding gap, and a cowl forming an air intake passage in a mutual gap between these lamps, and each movable plate of the front lamp and the rear lamp are rocked. Angle changing means for changing the angle are respectively provided, and a winding member for extending the front lamp is disposed at a rear end portion of the front lamp forming one end of the throat slot bleeding gap. The member is wound around an idler that has an axis parallel to the swing axis of the movable plate and is moved in a direction intersecting with the axis, and is arranged in a bent state. Tension means for applying tension to the winding member is provided. An air intake structure for a supersonic aircraft characterized by the following.