JPH07217449A - Supersonic engine - Google Patents

Abstract

PURPOSE:To recover a normal starting condition immediately even in a stall condition due to a change of a flying condition or the like by arranging a throat wall, a sealed type cylinder, a piston, and a rod connecting the piston and the throat wall together in the radius direction. CONSTITUTION:When an air inlet is in a starting condition, in other words, when a normal shock wave A is on the downstream side of a throat wall 2, air provided with the predetermined total pressure flows at the required flow rate into an inlet face 21 of an engine 20 on the air inlet downstream side. In this process, air flow on the upstream side of the normal shock wave A flows at supersonic speed, so that the pressure at the inlet 6a of a hole 6 is higher than the pressure at an inlet 7a of a hole 7, and a result, the pressure of a chamber 8 balanced with the pressure of the inlet 6a is higher than the pressure of the chamber 9 balanced with the pressure of the inlet 7a. Therefore, a piston 3 and the throat wall 2 connected to the piston 3 maintain a starting condition pressed downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine used for an aircraft, a spacecraft or a flying body which fly at supersonic speed, and more particularly to an air intake port thereof.

[0002]

2. Description of the Related Art The air intake of an engine of a conventional supersonic aircraft or the like has a fixed wall 1 from the front edge of the air intake as shown in FIG. 5 in a normal state when the aircraft is flying at supersonic speed. After that, air flows at supersonic speed until immediately after the throat, and decelerates to subsonic speed after the vertical shock wave A immediately after the throat. However, if the flight conditions change or the engine condition downstream of the air intake changes, a strong vertical shock wave A is formed in front of the air intake as shown in FIG. 6, and there is a large total pressure loss there. In some cases, the flow choked in some parts, making it impossible to pass the intended flow rate.

As a result, it has become impossible to supply air at a required pressure level to the engine at a required flow rate, which may hinder the operation of the engine.

Hereinafter, an engine used in a supersonic aircraft or the like will be referred to as a "supersonic engine".

[0005]

The above-mentioned conventional supersonic engine has the following problems to be solved.

That is, in the air intake of the conventional supersonic engine, the vertical shock wave moves to the front of the air intake depending on changes in flight conditions and engine conditions, and the flow rate is restricted by choking of the flow at the throat. There was a problem that it fell into a state (non-starting state).

In order to solve the above-mentioned problems, the present invention operates in a conventional manner under predetermined conditions, and immediately recovers to a normal starting state even if a non-starting state occurs due to changes in flight conditions and the like. It aims at providing the supersonic engine provided with.

[0008]

As a means for solving the above problems, the present invention takes in a supersonic flow of air from an air inlet whose cross-sectional area of an air flow path gradually decreases toward the downstream and minimizes the cross-sectional area. In a supersonic engine in which combustion air is generated after passing through the throat part, a throat wall provided so that the throat part can reciprocate toward the center of the flow path, and a radial outer peripheral side of the engine at the position of the dynamic throat wall. A sealed cylinder provided along the cylinder axis in the same radial direction, a piston reciprocally provided in the cylinder, and a rod connecting the piston and the throat wall in the radial direction. A supersonic engine comprising a hole penetrating the rod, the throat wall, and the piston, and a hole penetrating the bottom dead center side of the cylinder and the upstream side of the air intake. It is intended to test.

The term "bottom dead center side" means the piston / rod side of a cylinder, which is similar to a general cylinder and piston (although no crank actually exists). By the way, the top dead center is the reflection side, that is, the cylinder head side.

[0010]

Since the present invention is constructed as described above, it has the following actions.

That is, the throat wall of the air intake port is provided so as to be reciprocally movable toward the center of the flow path,
Since the sealed cylinder provided along the cylinder axis in the radial direction of the engine and the piston provided in the cylinder are connected by the rod in the radial direction of the engine, the throat wall, the rod, and the piston are It can reciprocate integrally in the radial direction.

On the other hand, since the rod, the throat wall and the piston are penetrated by the hole, and the bottom dead center side of the cylinder and the upstream side of the air intake are also penetrated by the hole, the sealed cylinder is closed. The top dead center side of the piston is equal to the pressure of the throat part through one hole, and the bottom dead center side of the piston is equal to the pressure on the upstream side of the air intake through the other hole.

On the other hand, when the air intake is in the starting state,
That is, when the supersonic speed is immediately after the throat, the pressure in the throat part is the upstream part of the throat (the upstream part of the air intake).
Since the pressure is higher than that of the piston, a pressure difference is generated on both sides of the piston, and the top dead center side becomes higher, so that the piston is pushed toward the center of the engine and operates so that the throat wall is held in the normal position ( The rod length is preset as such).

When the air intake is in a non-starting state due to changes in flight conditions and the like, the throat pressure becomes lower than the upstream pressure of the throat. The side is low, the bottom dead center side is high, and the throat wall moves outward in the radial direction. When the cross-sectional area of the throat portion expands, the vertical shock wave located at the upstream portion of the throat moves to the downstream portion of the throat and becomes in a starting state. In the starting state, the magnitude relationship between the pressures on both sides of the piston is reversed again, the cross-sectional area of the throat portion decreases to a normal value, and the vertical shock wave downstream of the throat is prevented from moving upstream of the throat.

That is, the air intake has a predetermined aerodynamic shape in the starting state, the throat cross-sectional area immediately expands in the non-starting state, the air intake enters the starting state, and returns to the starting state in the throat. Will return to the regular shape.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first and second embodiments of the present invention will be described with reference to FIGS. The overall longitudinal sectional view of the supersonic engine is shown in FIG. 1, and is shown on one side (upper side) of the engine center line in FIGS. The same components as those in the previous embodiment are designated by the same reference numerals, and the description thereof will be omitted unless necessary.

(First Embodiment) A first embodiment will be described with reference to FIGS.

FIG. 1 is an overall vertical sectional view of this embodiment (starting state), and FIG. 2 is a one-sided vertical sectional view of this embodiment (non-starting state).

In FIG. 1, the air intake of the supersonic engine is composed of a fixed wall 1, a throat wall 2, a piston 3 and a sealed cylinder 4. The throat wall 2 and the piston 3 are connected to each other by a rod 5 having a hole 6 formed in the axial center thereof. The hole 6 penetrates both the throat wall 2 and the piston 3 and communicates with the chamber 8 on the top dead center side of the cylinder 4.

The fixed wall 1 on the relatively upstream side of the air intake port and the chamber 9 on the bottom dead center side of the cylinder 4 communicate with each other through a hole 7.

Since this embodiment is constructed as described above, it operates as follows. When the air intake is in a starting state, that is, when the vertical shock wave A is downstream of the throat wall 2 as shown in FIG. 1, the inlet surface 21 of the engine 20 downstream of the air intake has a predetermined total pressure. The required amount of air flows in. At this time, the pressure of the inlet 6a of the hole 6 is higher than the pressure of the inlet 7a of the hole 7 because the air flow upstream of the vertical shock wave A has a supersonic velocity. It becomes higher than the pressure in the chamber 9 which balances the pressure at the inlet 7a. Therefore, the piston 3 and the throat wall 2 connected to the piston 3 maintain the starting state as shown in FIG. 1 which is pressed downward (toward the center of the flow path).

As shown in FIG. 2, when the air intake is in a non-starting state, that is, when the vertical shock wave A is pushed out to the front of the air intake, the air flow downstream of the vertical shock wave A becomes a subsonic speed and starts. Then, a part of the airflow flowing into the air intake overflows to the outside of the air intake, and the total pressure loss is larger than that in the starting state. Therefore, the engine entrance surface 2
It becomes impossible to supply the air having the predetermined total pressure to 1 at the required flow rate. However, in the case of this air intake,
In the non-starting state, the pressure in the inlet 7a becomes higher than the pressure in the inlet 6a, so that the pressure in the chamber 9 becomes higher than the pressure in the chamber 8 and the piston 3 moves upward. Moves upward, and the cross-sectional area of the throat portion flow path 10 facing the throat wall 2 increases. As a result, the air intake port is restarted and returned to the state shown in FIG.

That is, the vertical shock wave A moves to the downstream side of the throat wall 2 again, and the air having a predetermined total pressure flows into the inlet surface 21 of the engine 20 at a required flow rate, and the starting state is reproduced.

(Second Embodiment) A second embodiment will be described with reference to FIGS.

FIG. 3 is a one-side (upper) vertical sectional view showing the starting state of this embodiment, and FIG. 4 is a one-side (upper) vertical sectional view showing the non-starting state of this embodiment.

In the first embodiment, in the non-starting state (FIG. 2), a step is generated between the fixed wall 1 and the throat wall 2, and it is difficult to avoid a small failure in which the air flow is slightly disturbed. . In the second embodiment, a movable wall is additionally provided between the fixed wall 1 and the throat wall 2 to eliminate this.

In FIG. 3, the air intake is composed of a fixed wall 1, a throat wall 2, a piston 3, a cylinder 4, a rod 5, a hole 6, a hole 7, a chamber 8 and a chamber 9 as in the first embodiment. To be done. In the second embodiment, in addition to the components of the first embodiment, the movable wall 11 that connects the fixed wall 1 and the throat wall 2 and the hinge 12 and the movable wall 11 that connect the movable wall 11 to the throat wall 2 are fixed. And a hinge 13 connected to the wall 1. The hinge 12 is slidable along the elongated hole 14.

Since this embodiment is constructed as described above, it operates as follows. When the air intake is in the starting state, that is, when the vertical shock wave A is downstream of the throat wall 2 as shown in FIG. 3, the throat wall 2 is pushed downward as in FIG. 1 of the first embodiment. Stay in the state. When the air intake is in a non-starting state and the vertical shock wave A moves to the front of the air intake as shown in FIG. 4, FIG.
The throat wall 2 moves upward by the same principle as. This time,
The movable wall 11 has the hinge 13 as the center of rotation and the throat wall 2
Moves up with. Therefore, there is no step between the throat wall 2 and the fixed wall 1, and the flow passage cross-sectional area facing the throat wall 2 is expanded.

As a result, the air intake is started, the vertical shock wave A moves downstream of the throat wall 2, and returns to the state shown in FIG.

As described above, the second embodiment operates in the same manner as the first embodiment, but when the throat wall 2 moves upward, there is no step between the throat wall 2 and the fixed wall 1, so that the flow is prevented. There is an advantage that it is possible to return from the non-starting state to the starting state without causing great disturbance.

As described above, according to the first and second embodiments, the vertical shock wave moves to the front surface of the air intake port due to flight conditions and the like, and the throat portion is formed even when the intake air flow rate is reduced and the engine is in a non-starting state. The throat wall 2 immediately moves to the outer peripheral side of the engine, the flow passage cross-sectional area of the throat portion expands, and the vertical shock wave A moves to the position immediately after the throat portion again to recover the starting state. There is an advantage that the intake air amount does not become insufficient.

Further, according to the second embodiment, there is an advantage that the air flow passing through the throat portion is not disturbed even in the non-starting state, and the decrease in pressure loss is correspondingly small.

[0033]

Since the present invention is constructed as described above, it has the following effects.

That is, according to the present invention, even if the air intake is brought into a non-starting state due to a change in flight conditions, the flow passage cross-sectional area of the throat portion is automatically increased to restore the starting state, so that The required air can always be supplied stably.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an entire supersonic engine (starting state) according to a first embodiment of the present invention,

FIG. 2 is a longitudinal sectional view of one side of a supersonic engine (non-starting state) according to the first embodiment,

FIG. 3 is a longitudinal sectional view of one side of an air intake (starting state) according to a second embodiment of the present invention,

FIG. 4 is a longitudinal sectional view of one side of an air intake (non-starting state) according to the second embodiment,

FIG. 5 is a vertical cross-sectional view showing a starting state of a conventional air intake port,

FIG. 6 is a vertical cross-sectional view showing a non-starting state of a conventional air intake.

[Explanation of symbols]

 1 Fixed Wall 2 Throat Wall 3 Piston 4 Cylinder 5 Rod 6,7 Hole 8,9 Chamber 10 Throat Flow Path 11 Movable Wall 12,13 Hinge 14 Long Hole A Vertical Shock Wave 20 Engine 21 Entrance Surface

Claims (1)

[Claims] 1. A supersonic engine in which air having a supersonic flow is taken in from an air intake whose cross-sectional area of an air flow path gradually decreases toward the downstream side, and is made into combustion air after passing through a throat portion having the minimum cross-sectional area. The throat portion is provided so as to reciprocate toward the center of the flow path, and the cylinder shaft is provided along the radial direction on the radially outer side of the engine at the position of the dynamic throat wall. A sealed cylinder, a piston reciprocally provided in the cylinder, a rod connecting the piston and the throat wall in the radial direction, and a hole penetrating the rod, the throat wall, and the piston. , A supersonic engine comprising a hole penetrating the bottom dead center side of the cylinder and the upstream side of the air intake.