JP2687803B2 - Scrumjet engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scramjet engine used for hypersonic flying objects such as space planes.

[0002]

2. Description of the Related Art In recent years, hypersonic projectiles exceeding Mach 5 such as space planes have been proposed. As an engine used for such hypersonic projectiles, a method of flowing air at supersonic speed inside the engine as well. Scram Jet (SCRAM JET: Supersonic Com
The Fusion RAM JET) engine is being researched.

As shown in FIG. 7, a scramjet engine includes an air inlet 102, a throat portion 103, a combustor 104, between a pair of side plates 101, 101.
A nozzle (not shown) is continuously provided, and two fuel supply struts 105, 105 are provided in parallel at the position of the throat portion 103.

The strut 105 has steps 106 and 106 for holding flame on both sides, and the side injection port 1 in the direction intersecting with the air flow is provided on the downstream side of each step 106.
07, a rear end injection port 108 in a direction parallel to the air flow, and a fuel supply passage 10 communicating with the injection ports 107 and 108 inside.
9,110 are provided. These injection ports 107, 10
A plurality of fuel cells 8 are provided at predetermined intervals in the vertical direction, and the fuel supply paths 109 and 110 are provided in the vertical direction of the struts 105.

Further, the strut 105 has a cooling liquid supply passage 111 on the front end side inside thereof, and a cooling liquid discharge passage 112 on the rear end side thereof in the vertical direction, and at the outer peripheral portion,
A cooling liquid flow path 113 having a channel structure is formed. A large number of the cooling liquid passages 113 are provided at predetermined intervals in the vertical direction of the struts 105.

[0006] In the above scramjet engine, the inflowing air is decelerated and compressed by the air inlet 102, and fuel (for example, hydrogen) is injected into the air from each of the injection ports 107 and 108 to continuously burn the combustion gas. Thrust is obtained by ejecting from the nozzle. Further, by colliding the cooling liquid from the cooling liquid supply path 111 to the inside of the front end portion of the strut 105, the strut front end portion having a particularly high temperature rise is cooled, and the cooling liquid is discharged from the cooling liquid flow passage 113 on the outer periphery. By flowing to the path 112,
I try to cool the whole thing.

The structure of the above scramjet engine and strut is NASACR 159039.
"Thermal-Structural Desi
gn Study of an Airframe-I
ntegrated Scramjet Final
Report, "page 68, Figure 36.

[0008]

However, in the scramjet engine as described above, the strut 105 is used.
Lateral diffusion of the fuel injected from the rear end injection port 108 in parallel with the air flow was slow, and a thick portion of the fuel was formed behind the struts, and it was difficult to obtain sufficient mixing efficiency.
Further, since the cooling system in which the cooling liquid is circulated in the cooling liquid flow passage 113 having the channel structure formed on the outer periphery of the strut 105 is adopted, the structure is complicated and there is a problem that it takes a lot of time and effort to manufacture. .

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and in a scramjet engine, improves the mixing efficiency of introduced air and fuel, and
The purpose is to realize a sufficient cooling function with a simple structure.

[0010]

According to a first aspect of the present invention, there is provided a scramjet engine according to claim 1, wherein a front end portion for an air flow has a substantially pointed cross section and a side portion in an air passage in front of the combustor. A fuel supply strut having a flame-holding step, and a side injection port for injecting fuel in a direction intersecting an air flow is provided in the vicinity of a downstream side of the flame-holding step of the strut, and The front end portion of the strut is provided with a front end portion injection port for injecting fuel rearward along the side surface of the strut, wherein
A fuel supply path is provided inside the strut, and a fuel flow path that reaches the inside of the front end portion of the strut from the fuel supply path and is bent backward to reach the front end injection port is provided. The structure is used as a means for solving the problem. Liquid hydrogen, for example, is used as the fuel for the scramjet engine.

[0011]

In the scramjet engine according to the present invention, the fuel is injected rearward from the front end injection port of the strut and the fuel is injected from the side injection port in a direction intersecting with the air flow. All of the fuel is injected directly into the air stream passing through the sides of the and the mixing of the air and fuel is sufficient.

Further, in the scramjet engine according to the present invention, the fuel serves as a cooling liquid. That is, the fuel injected backward from the front end injection port of the strut flows along the side surface of the strut to reduce the heat load on the front end side of the strut, and burns behind the flame holding step.

Further, by providing a fuel flow path inside the strut from the fuel supply path to the inside of the front end of the strut and by bending backward, to the front end injection port, the front end of the strut from the fuel supply path is provided. The fuel is made to collide with the inside of the part, and the front end of the strut, which has a particularly high temperature rise, is cooled.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to claims 1 and 2 of the present invention will be described below with reference to FIGS.

FIG. 4 is a diagram showing an example of a hypersonic flying vehicle. This hypersonic flying vehicle F is integrally provided with six scramjet engines J on the lower surface of the rear portion of the airframe.

The scramjet engine J is shown in FIG.
Further, as shown in FIG. 6, the entire flow path is formed by the pair of side plates 1, 1 and the lower engine cowl 2.
Between the both side plates 1 and 1, the air inlet 3 whose flow passage area is gradually reduced, the throat portion 4, the combustor 5 whose flow passage area is gradually expanded, and the nozzle 6 are continuously provided, and combustion is performed. Two fuel supply struts 7, 7 are provided in parallel at the position of the throat portion 4 which is an air flow path in front of the container.

The strut 7 has a horizontal section shown in FIG.
As shown in FIG. 3, the front end portion for the air flow has a wedge-shaped front half portion 8 having a substantially pointed cross section, and the width dimension is gradually reduced rearward after maintaining a constant width dimension. It has a portion 9, and flame holding steps 10 and 10 are provided in the vertical direction at the boundaries between the front half portion 8 and the rear half portion 9 on both sides.

Inside the strut 7, the fuel supply passages 11, 11 are provided at the front and rear positions of the flame holding step 10.
12 is formed in the vertical direction, and a space portion 13 through which the cooling liquid and the like can flow is also formed in the vertical direction at the rear end portion.

Further, the strut 7 is provided with a plurality of side injection ports 14 for injecting fuel in a direction intersecting the air flow at predetermined intervals in the vertical direction in the vicinity of the downstream side of each flame holding step 10. There is. These side injection ports 14 communicate with the fuel supply passage 12 on the rear side. Further, on both sides of the strut 7 in the vicinity of the front end portion, rearward facing step portions 15,
As shown in FIG. 2, a front end injection port 16 for injecting fuel rearward along the side surface of the strut 7 is provided at a predetermined interval in the vertical direction on each stepped portion 15. Many are formed.

A front side fuel supply passage 11 communicates with the front end injection port 16. Here, as shown in FIG. 3, the fuel flow path 17 extends linearly forward from the fuel supply path 11 to reach the inside of the front end portion of the strut 7, is divided into both sides, and is bent backward to form the front end. The state reaches the partial injection port 16. In addition, it is more preferable that the fuel flow path 17 is configured to be continuous in the vertical direction in order to further enhance the cooling efficiency.

The scramjet engine J having the above structure decelerates and compresses the inflowing air by the air inlet 3, and injects the fuel into the airflow passing through the throat part 4 to continuously burn it in the combustor 5. The thrust is obtained by ejecting the combustion gas from the nozzle 6. Liquid hydrogen is used as the fuel, for example. Also,
In the hypersonic flying object F as shown in FIG. 4, the pressure rise due to the shock wave generated from the tip of the fuselage may be used to cause the air compressed under the fuselage to flow into the engine.

Then, the above scrumjet engine J
Then, by injecting the fuel rearward along the side surface of the strut 7 from the front end injection port 16 and injecting the fuel from the side injection port 14 substantially at right angles to the air flow, the side portion of the strut 7 is All fuel is injected directly into the passing air stream in order to ensure a good mixture of these.

Further, in the scramjet engine J, the fuel plays the role of a cooling liquid. That is, on the front end side of the strut 7, the fuel that has been pressurized and passes through the fuel flow passage 17 from the front fuel supply passage 11 collides with the inside of the front end portion of the strut 7, and the front end portion of the strut where the temperature rises especially is cooled. doing. Further, the fuel injected rearward from the front end injection port 16 through the fuel flow path 17 flows along the side surface of the strut 7 to reduce the heat load on the front end side of the strut 7, as shown by the arrow in FIG. Then, the combustion is performed behind the flame holding step 10.

As described above, the scramjet engine J has no fuel injection port at the rear end of the strut 7,
The fuel is injected into the air flow passing through the side portions of the struts 7 so as to obtain good mixing efficiency, and the structure is simple but has a sufficient cooling function.

[0025]

As described above, according to the scramjet engine of the present invention, all the fuel is injected into the air flow passing through the side portion of the strut. The mixing efficiency can be significantly increased, and the combustion efficiency can be improved. In addition, the structure of the fuel flow path that reaches the inside of the front end of the strut from the fuel supply path and bends backward to reach the front end injection port, and by utilizing the fuel as the cooling liquid, sufficient cooling of the front end of the strut is achieved. The function can be realized with a simple structure, and the strut can be easily manufactured, which is an excellent effect.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing a main part of a scramjet engine according to an embodiment of the present invention.

2 is a horizontal cross-sectional view illustrating the flow of fuel at the front end portion of a strut in the scramjet engine shown in FIG.

3 is a perspective view showing a front end portion of a strut of the scramjet engine shown in FIG. 1. FIG.

FIG. 4 is a perspective view showing a hypersonic vehicle equipped with a scramjet engine.

5 is a side cross-sectional view of the scramjet engine shown in FIG.

6 is a horizontal cross-sectional view of the scramjet engine shown in FIG.

FIG. 7 is a horizontal cross-sectional view illustrating a conventionally proposed scramjet engine.

[Explanation of symbols]

 J Scramjet engine 5 Combustor 7 Strut 10 Flame holding step 11 Fuel supply path 12 Fuel supply path 14 Side injection port 16 Front end injection port 17 Fuel flow path

Claims (2)

(57) [Claims] 1. A strut for supplying fuel having a front end portion for the air flow having a substantially pointed cross section and a step for holding flame on a side portion is provided in an air flow passage in front of the combustor. A side injection port for injecting fuel in a direction intersecting with the air flow is provided in the vicinity of the downstream side of the flame holding step, and fuel is injected backward along the side surface of the strut at the front end of the strut. A scramjet engine having a front end injection port that 2. The scramjet engine according to claim 1, wherein a fuel supply passage is provided inside the strut, and the front end injection is performed by extending from the fuel supply passage to the inside of the front end portion of the strut and bending backward. A scramjet engine characterized by having a fuel flow path to the mouth.