JPH0772518B2 - Cooling device for scramjet engine with variable cooling passage section - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a scramjet engine, and more particularly to a cooling device for a scramjet engine which realizes high cooling performance and light weight.

[0002]

2. Description of the Prior Art Scramjet engines operate at extremely high flight Mach numbers and are therefore exposed to severe aerodynamic heating and heating by hot combustion gases, so their structure is lightweight, highly heat resistant, and fuel-efficient. Regeneration cooling needs to be applied. Moreover, because the fuel flow rate is limited,
It is known that the cooling limit becomes the operating limit of the scramjet engine.

In particular, a scramjet engine is characterized by supersonic combustion in which fuel is injected into a supersonic air stream for combustion. Therefore, shock waves generated at the front edge of the air intake port and the front edge of the fuel injection strut collide with the opposing wall surface, resulting in an extremely high local high heat load of several tens of times, resulting in local red heat and, in some cases, local heat. Is known to cause heat loss. Moreover, this local high heat load part moves with the increase of the flight Mach number, which is an extremely difficult task in terms of thermal design. In the conventional design method, a large cooling margin was taken in order to deal with this, but on the other hand, a large pressure loss of the coolant and an increase in weight due to the pressure increase of the entire system were brought.

[0004]

DISCLOSURE OF THE INVENTION The present invention deals with a locally high heat load portion that moves with an increase in the flight Mach number in a scramjet engine, and increases the flow velocity of the coolant in that portion to obtain a high cooling capacity. At the same time, in other low heat load parts, the coolant is kept at a low flow rate to suppress the increase of pressure loss, and the pressure of the coolant is lowered as a whole to achieve the weight reduction and the high performance of the engine. .

[0005]

In the cooling device for a scramjet engine of the present invention, a member for reducing the cross section of the cooling passage is movably disposed in the regenerative cooling section in the vicinity of a high heat load section generated by a shock wave. The cooling passage section is variable.

[0006]

FIG. 1 is a perspective view of a part of a cut surface of the cooling device for explaining the operation of the cooling device of the present invention. In the figure,
Reference numeral 1 denotes a cooling wall having a groove 2 serving as a passage for a coolant, 3 denotes a movable protrusion for locally making the coolant flow at a high speed, 4
Is a drive unit for moving the protrusion 3. If the coolant is made to flow in the wall of the scramjet engine having such a cooling structure, the flow velocity of the coolant is locally increased by the protrusions 3, and a high cooling capacity can be obtained. If the projection 3 is located at a position where the shock wave collides and the heat load locally becomes extremely high, the cooling capacity is sufficiently high locally, so that the wall material can be prevented from becoming red-heated and burned. I can.

FIG. 2a shows a flight at a low Mach number, and the shock wave 7 generated when the hot air stream 5 hits the front end of the fuel injector 6 hits the cooling wall 1 as shown in FIG. 2b.
When flying at high Mach numbers, it moves further back. As described above, the high heat load portion changes every moment as the flight Mach number increases, and the protrusion 3 is moved by the drive unit 4 in response to the change, so that the portion having high cooling capacity is always changed to the high heat load portion. By moving them in line with each other, the wall temperature can always be kept within the allowable range.

On the other hand, in most of the other parts, the pressure loss is extremely small because the flow velocity of the coolant is slow, and the projection 3
Even if a partial pressure loss increases due to, it can be ignored for the entire system. In this way, the pressure loss of the coolant, and consequently the pressure level of the entire system, can be suppressed to a low level, the weight of the engine can be reduced, and there is a margin in the cooling capacity, which enables flight at a higher Mach number.

[0009]

EXAMPLE A cooling wall 1 is formed by cutting a groove 11 in the axial direction of a combustion chamber by machining as shown in FIG. 3B on a cylinder 11 of copper or copper alloy having good heat conductivity as shown in FIG. Then, the outer cylinder 13 is attached by brazing, electroforming or the like as shown in FIG. Therefore, at the time of this machining, as shown in FIG. 4, the groove 12 can be provided with an expanded portion 14 on the upper portion thereof, and the drive portion 16 of the protrusion 15 can be fitted therein to form a sliding groove. When the outer cylinder 13 is made of copper or a copper alloy, the drive unit 16 can be driven from the outside of the outer cylinder 13 with a magnet (not shown) by incorporating a magnetic material in the drive unit. The magnetic material loses its magnetism when it exceeds the Curie point, but hydrogen, which is a coolant,
Since it flows into the cooling passage at 253 ° C. and exits at about 500 ° C., the magnetic substance may be arranged in a portion that does not exceed the Curie point of the drive portion 16 extending along the groove 12.

A rack may be provided in the drive unit 16 and the drive unit may be mechanically slid by a pinion extending to the outside of the outer cylinder 13. In this case, since the seal portion is only the portion where the pinion penetrates the outer cylinder, the sealing is easy.

[0011]

According to the present invention, with the above-described structure, the cooling capacity is locally and sufficiently enhanced only at the position where the heat load is extremely high on the side wall where the shock waves that change momentarily with the increase of the flight Mach number collide. It is possible to avoid red heat and burnout of the wall material. On the other hand, in most of the other parts, the pressure loss of the coolant can be kept extremely small and the pressure level of the entire system can be kept low, so that the weight of the engine can be reduced,
Further, there is a remarkable effect that the cooling capacity has a margin and the flight at a higher Mach number becomes possible.

[Brief description of drawings]

FIG. 1 is a conceptual diagram for explaining the operation of a cooling device of the present invention.

FIG. 2 is an explanatory diagram of shock waves generated in a combustion chamber.

FIG. 3 is an explanatory diagram of a manufacturing process of a cooling wall.

FIG. 4 is a perspective view of a partial cross section of an embodiment of the present invention.

[Explanation of symbols]

1 Cooling wall 2 Grooves that serve as coolant passages
3,15 Protruding part 4,16 Driving part 5 High temperature air flow
6 Fuel injector 7 Shock wave 11 Cylinder
12 groove 13 outer cylinder 14 sliding groove

Claims (1)

[Claims] 1. A regenerative cooling section of a scramjet engine, wherein a member for reducing the cross section of the cooling path is movably arranged near a high heat load section generated by a shock wave, and the cross section of the cooling path is variable. Scrumjet engine cooling system