JP2012207555A - Scramjet engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scramjet engine capable of preventing thermal choking.SOLUTION: An airflow channel 3 of the scramjet engine 11 is formed to connect a front opening provided on a front side with a rear opening provided on a rear side. The airflow channel includes: an upstream region 8 for taking in the air through the front opening during supersonic flight; a fuel supply region 6 connected with a rear side of the upstream region where fuel is supplied and the intake air burns to generate combustion gas; and a downstream region 7 connected with a rear side of the fuel supply region for jetting the combustion gas through the rear opening. The fuel supply region includes a front supply region 6-1 provided on the front side and a rear supply region 6-2 provided on the rear side. The downstream region is formed to be larger in cross section as coming to the rear side.

Description

  The present invention relates to a scramjet engine.

  Flying objects that fly at supersonic speeds are known. The flying body may use a scramjet engine as a propulsion device during supersonic flight.

  FIG. 1 is a schematic sectional view showing an example of a scramjet engine. The scramjet engine 100 includes a cowl 102 (flow path forming member) attached to an airframe 101 and a fuel supply mechanism 104. An air flow path 103 is formed between the cowl 102 and the body 101. The fuel supply mechanism 104 has a function of injecting fuel into the air flow path 103.

  Supersonic air is taken into the air flow path 103 from the front side in the traveling direction. The taken-in air is compressed in the vicinity of the inlet of the air flow path 103 and decelerates within a range where the supersonic state is maintained. The compressed and decelerated air is burned by the fuel injected by the fuel supply mechanism 104 to generate combustion gas. The combustion gas expands, accelerates, and is injected toward the rear side from the air flow path 103. Thereby, the thrust for propelling the body 101 is obtained.

  By the way, in the scramjet engine 100, thermal blockage may occur. FIG. 2 is a schematic diagram showing the scramjet engine 100 when thermal blockage occurs. For example, if the amount of fuel supplied is excessive, the amount of heat generated during combustion increases, and heat blockage occurs in the air flow path 103. When the thermal blockage occurs, heat due to the mass of the fuel and combustion is added to the air flowing at supersonic speed, and the flow velocity of the air is reduced to subsonic speed. That is, the combustion state becomes a subsonic combustion state. As a result, thrust cannot be obtained. Therefore, it is desirable to prevent the occurrence of thermal blockage.

  A technique related to the scramjet engine is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 7-4314). Patent Document 1 discloses a scramjet engine that includes a flow path that includes a front opening, a central cavity, and a rear opening, and includes a device that injects hydrogen into the central cavity. A scramjet engine is disclosed in which a part of the member to be moved is made movable so that the front opening can be closed and an apparatus for injecting oxygen into the central cavity is additionally installed.

Japanese Patent Laid-Open No. 7-4314

  In order to avoid thermal blockage, it is conceivable to provide an opening angle in the air flow path 103. FIG. 3 is a schematic view showing an example of the air flow path 103 provided with an opening angle. FIG. 3 illustrates a configuration of a portion where fuel is injected in the air flow path 103. In the example shown in FIG. 3, the air flow path 103 is formed so that its cross-sectional area becomes wider toward the rear side. That is, the air flow path 103 is provided with an opening angle (an angle formed by the lower surface of the airframe 101 and the upper surface of the cowl 102). By adopting such a configuration, the air flow is accelerated and it becomes easy to avoid the occurrence of thermal blockage. However, depending on the size of the opening angle, ignition and flame holding may become unstable and flame holding may not be continued.

  As another method for avoiding thermal clogging, a method of limiting the amount of fuel supply can be considered. That is, by restricting the fuel supply amount to an amount that does not cause thermal blockage, thermal blockage can be prevented. However, when the fuel supply amount is limited, the thrust obtained with respect to the engine size is reduced, and the engine efficiency is lowered.

  Therefore, the subject of this invention is providing the scramjet engine which can prevent a thermal obstruction | occlusion.

  A scramjet engine according to the present invention includes an air flow path forming member attached to the airframe so as to form an air flow path, and a fuel supply mechanism for supplying fuel into the air flow path. To do. The air flow path is formed to connect a front opening provided on the front side and a rear opening provided on the rear side. The air flow path is connected to the upstream region, which takes in air through the front opening during supersonic flight, and the rear side of the upstream region, the fuel is supplied, and the taken-in air burns, A fuel supply region that generates combustion gas; and a downstream region that is connected to a rear side of the fuel supply region and ejects the combustion gas through the rear opening. The fuel supply region includes a supply region front portion provided on the front side and a supply region rear portion provided on the rear side. The downstream region is formed so that a cross-sectional area increases toward the rear side. The amount of increase in cross-sectional area per unit length in the downstream region is larger than that in the front portion of the supply region.

  According to the above-described invention, the downstream region is formed so that the cross-sectional area increases toward the rear side. Therefore, supersonic air flowing through the air flow path can be accelerated in the downstream region, and thermal blockage can be avoided. On the other hand, the increase amount of the cross-sectional area is smaller in the front portion of the supply region than in the downstream region. In the fuel supply region, the speed at which air flows can be suppressed, and ignition and flame holding can be performed stably. Further, according to the above-described invention, thermal blockage can be avoided at a larger fuel supply amount, so that engine efficiency can be improved.

  According to the present invention, it is possible to provide a scramjet engine that can prevent thermal blockage.

It is a schematic sectional drawing which shows an example of a scramjet engine. It is the schematic which shows a scramjet engine in case heat | fever occlusion generate | occur | produced. It is the schematic which shows an example of the air flow path provided with the opening angle. 1 is a schematic view showing a scramjet engine according to a first embodiment. It is the schematic which shows the scramjet engine which concerns on the modification of 1st Embodiment. It is the schematic which shows the scramjet engine which concerns on the other modification of 1st Embodiment. It is the schematic which shows the scramjet engine which concerns on the other modification of 1st Embodiment. It is the schematic which shows the scramjet engine which concerns on the other modification of 1st Embodiment. It is the schematic which shows the scramjet engine which concerns on the other modification of 1st Embodiment. It is the schematic which shows the scramjet engine which concerns on 2nd Embodiment. It is the schematic which shows the scramjet engine which concerns on the 1st modification of 2nd Embodiment. It is the schematic which shows the scramjet engine which concerns on the 2nd modification of 2nd Embodiment. It is the schematic which shows the scramjet engine which concerns on the 3rd modification of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 4A is a schematic view showing the scramjet engine 11 according to the present embodiment. The scramjet engine 11 according to the present embodiment includes a cowl 2 (flow path forming member) attached to the airframe 1 and a fuel supply mechanism 9 as in the example shown in FIG. In FIG. 4A, unlike FIG. 1, the cowl 2 is drawn on the upper side, and the body 1 is drawn on the lower side.

  As shown in FIG. 4A, an air flow path 3 is formed between the cowl 2 and the body 1. Specifically, the airframe 1 has a first surface 4. The cowl 2 has a second surface 5. The cowl 2 is attached to the airframe 1 so that the second surface 5 faces the first surface 4. The air flow path 3 is formed between the first surface 4 and the second surface 5.

  The fuel supply mechanism 9 is configured to supply fuel (for example, hydrogen and jet fuel) into the air flow path 3. For example, the fuel supply mechanism 9 injects fuel into the air flow path 3 via a fuel nozzle (not shown) provided on the wall surface of the air flow path 3.

  The air flow path 3 is connected to the front opening at the front end in the traveling direction, and is connected to the rear opening at the rear end. The air flow path 3 has an upstream region 8, a fuel supply region 6, and a downstream region 7 from the front side.

  The upstream region 8 is a portion that takes in supersonic air through the front opening and guides it to the fuel supply region 6. As shown in FIG. 4A, the upstream region 8 includes a reduced diameter portion 8-1 and a connection portion 8-2. The reduced diameter portion 8-1 is a portion that compresses and decelerates supersonic air, and is connected to the front opening at the front end portion and connected to the connection portion 8-2 at the rear end portion. . In the reduced diameter portion 8-1, the cross-sectional area of the air flow path 3 becomes smaller toward the rear side. On the other hand, the connection portion 8-2 is a portion that connects the reduced diameter portion 8-1 and the fuel supply region 6. The cross-sectional area of the air flow path 3 in the connection part 8-2 is substantially constant.

  The fuel supply area 6 is a portion to which fuel is supplied by the fuel supply mechanism 9. The air introduced from the upstream region 8 into the fuel supply region 6 is combusted by the supplied fuel and generates combustion gas. As shown in FIG. 4A, the fuel supply region 6 includes a supply region front portion 6-1 and a supply region rear portion 6-2. The first surface 4 of the machine body 1 is provided with a recess 10 in a supply region rear portion 6-2. The fuel is supplied from the fuel supply mechanism 9 only from the supply region front part 6-1 or from only the supply region rear part 6-2 or from both the supply region front part 6-1 and the supply region rear part 6-2. It is injected into the region 6.

  The downstream region 7 is connected to the fuel supply region 6 at the front end and is connected to the rear opening at the rear end. In the downstream region 7, the cross-sectional area of the air flow path 3 increases toward the rear side. Specifically, an opening angle is provided in the downstream region 7. That is, in the downstream region 7, the distance between the first surface 4 and the second surface 5 is such that the downstream region 7 opens toward the rear side (so that the distance between the first surface 4 and the second surface 5 increases). Is provided with an angle. In the example shown in FIG. 4A, the second surface 5 in the downstream region 7 is provided on the same plane as the second surface 5 in the fuel supply region 6. On the other hand, the first surface 4 in the downstream region 7 extends obliquely with respect to the first surface 4 in the fuel supply region 6. As a result, the air flow path 3 starts to open at the connecting portion between the fuel supply region 6 and the downstream region 7. Note that the air flow path 3 does not necessarily start to open at the connecting portion between the fuel supply region 6 and the downstream region 7. For example, as shown in FIG. 4B, the inclination of the first surface 4 may start from the middle of the supply region rear portion 6-2 (A in FIG. 4B).

  Here, the amount of increase in the cross-sectional area per unit length in the downstream region 7 is larger than that in the supply region front portion 6-1. That is, the increase amount of the cross-sectional area per unit length in the supply region front portion 6-1 is 0 or smaller than that in the downstream region 7.

  In the present embodiment, supersonic air is taken into the air flow path 3 through the front opening during supersonic flight. The taken-in air is compressed in the reduced diameter portion 8-1, is decelerated within a range in which the supersonic state is maintained, and is guided to the fuel supply region 6 through the connection portion 8-2. The air introduced into the fuel supply region 6 is combusted by the fuel injected by the fuel supply mechanism 9 to generate combustion gas. The combustion gas expands and accelerates in the downstream region 7 and is ejected through the rear opening. Thereby, the propulsive force which propels the body 1 is obtained.

  Here, in this embodiment, the amount of increase in cross-sectional area per unit length in the supply region front portion 6-1 is smaller than that in the downstream region 7. Therefore, in the fuel supply region 6, the air flow rate is suppressed. Therefore, in the fuel supply region 6, ignition and flame holding can be performed stably. On the other hand, the amount of increase in cross-sectional area per unit length in the downstream region 7 is larger than that in the supply region front portion 6-1. Therefore, in the downstream region 7, the air flow rate can be accelerated. Therefore, even when the amount of fuel supply becomes excessive, an increase in pressure in the fuel supply region 6 can be prevented, and thermal blockage can be avoided.

  In the present embodiment, a recess 10 is provided in the supply region rear portion 6-2, and fuel is injected from the recess 10 into the air flow path 3. By adopting such a configuration, it is possible to prevent the flame from being blown out by the air flow, and to perform ignition and flame holding more stably. However, the fuel supply method is not limited to the example shown in FIG. 4A, and it is also possible to supply fuel using other methods.

  In the present embodiment, the first surface 4 in the downstream region 7 is inclined with respect to the first surface 4 in the fuel supply region 6. However, the 1st surface 4 does not necessarily incline in the downstream area | region 7, and the increase amount of the cross-sectional area per unit length in the supply area front part 6-1 should just be smaller than that in the downstream area | region 7. . For example, a configuration such as a modified example described below may be employed.

  FIG. 5A is a schematic view showing a scramjet engine 11 according to a modification of the present embodiment. In this modification, the first surface 4 is formed on the same plane between the fuel supply region 6 and the downstream region 7. On the other hand, the second surface 5 in the downstream region 7 is inclined with respect to the second surface 5 in the fuel supply region 6. Thereby, the increase amount of the cross-sectional area per unit length in the downstream area | region 7 is larger than that in the supply area front part 6-1. Even if such a configuration is adopted, the same operational effects as in the present embodiment can be obtained. Further, similarly to the example shown in FIG. 4B, the air flow path 3 may start to open from the middle of the supply region rear portion 6-2. FIG. 5B is a schematic diagram illustrating such an example. In the example shown in FIG. 5B, the inclination of the second surface 5 starts in the middle of the supply region rear portion 6-2. Even if the configuration shown in FIG. 5B is adopted, the same effect as that of the present embodiment can be obtained.

  FIG. 6A is a schematic view showing a scramjet engine 11 according to another modification of the present embodiment. In this modification, the first surface 4 in the downstream region 7 extends with an inclination with respect to the first surface 4 in the fuel supply region 6. The second surface 5 in the downstream region is also inclined with respect to the second surface in the fuel supply region 6. Thereby, the increase amount of the cross-sectional area per unit length in the downstream area | region 7 is larger than that in the supply area front part 6-1. Even if such a configuration is adopted, the same operational effects as in the present embodiment can be obtained. Furthermore, similarly to the example shown in FIG. 4B, the air flow path 3 may start to open from the middle of the supply region rear portion 6-2. FIG. 6B is a schematic diagram showing such an example. In the example shown in FIG. 6B, the inclination of the first surface 4 and the second surface 5 starts in the middle of the supply region rear portion 6-2. Even if the configuration shown in FIG. 6B is adopted, the same effect as that of the present embodiment can be obtained.

(Second Embodiment)
Subsequently, a second embodiment of the present invention will be described. FIG. 7 is a schematic view showing the scramjet engine 11 according to the present embodiment. In the present embodiment, the configuration in the upstream region 8 is changed with respect to the first embodiment. About another point, since the structure similar to 1st Embodiment is employable, detailed description is abbreviate | omitted.

  As shown in FIG. 7, the connection area 8-2 in the upstream area 8 is provided with a constant cross-sectional area portion 8-2-1 and a cross-sectional area enlarged portion 8-2-2. The constant sectional area portion 8-2-1 is connected to the reduced diameter portion 8-1 at the front end portion. The cross-sectional area of the air flow path 3 in the constant cross-sectional area portion 8-2-1 is constant. On the other hand, the cross-sectional area enlarged portion 8-2-2 is connected to the constant cross-sectional area portion 8-2-1 at the front end portion, and is connected to the fuel supply region 6 at the rear end portion. The cross-sectional area 3 of the air flow path in the cross-sectional area enlarged portion 8-2-2 is enlarged toward the rear side. In the present embodiment, in the cross-sectional area enlarged portion 8-2-2, the first surface 4 is inclined and extends, so that the cross-sectional area in the cross-sectional area enlarged portion 8-2-2 increases toward the rear side. It has become. In addition, the 2nd surface 5 is not inclined in the cross-sectional area expansion part 8-2-2. That is, the second surface 5 is formed on the same plane in the constant cross-sectional area portion 8-2-1 and the cross-sectional area enlarged portion 8-2-2.

  According to the present embodiment, as in the first embodiment, the amount of increase in cross-sectional area per unit length in the supply region front portion 6-1 is smaller than that in the downstream region 7. Therefore, in the fuel supply region 6, an increase in the air flow rate can be suppressed, and ignition and flame holding can be performed stably. Moreover, the increase amount of the cross-sectional area per unit length in the downstream area | region 7 is larger than that in the supply area front part 6-1. Accordingly, in the downstream region 7, the air flow rate can be accelerated, and thermal blockage can be avoided.

  In addition, according to the present embodiment, in the upstream region 8, the cross-sectional area enlarged portion 8-2-2 is provided. Therefore, even if thermal clogging is likely to occur, the progression of thermal clogging can be avoided. When the thermal blockage occurs, the air flow velocity in the fuel supply region 6 is reduced to the subsonic speed. Then, the air that has been reduced to the subsonic speed flows backward to the upstream side of the air flow path 3, so that the thermal blockage proceeds. In the present embodiment, since the cross-sectional area enlargement portion 8-2-2 is provided, even if the air flow velocity in the fuel supply region 6 is reduced, the cross-sectional area enlargement portion 8-2-2. In addition, the air is prevented from flowing back to the upstream side. As a result, the progress of the thermal blockage is suppressed, and the thermal blockage can be avoided.

  In the present embodiment, the first surface 4 extends in an inclined manner in the cross-sectional area enlarged portion 8-2-2. However, the cross-sectional area of the cross-sectional area enlarged portion 8-2-2 only needs to increase toward the rear side, and the configuration illustrated in FIG. 7 is not necessarily employed. For example, it is possible to adopt a configuration as in a first modification described below.

  FIG. 8 is a schematic view showing a scramjet engine 11 according to a first modification of the present embodiment. In the present modification, the second surface 5 extends in an inclined manner in the cross-sectional area enlarged portion 8-2-2. On the other hand, the first surface 4 is provided on the same plane in the constant cross-sectional area portion 8-2-1 and the cross-sectional area enlarged portion 8-2-2. Thereby, the cross-sectional area in the cross-sectional area enlarged portion 8-2-2 is enlarged toward the rear side. Even if the configuration as in this modification is employed, the same effect as in the present embodiment can be obtained.

  Further, similarly to the first embodiment, the downstream region 7 only needs to be configured such that the cross-sectional area increases toward the rear side.

  FIG. 9 is a schematic view showing a scramjet engine 11 according to a second modification of the present embodiment. In the present modification, the first surface 4 extends in an inclined manner in the cross-sectional area enlarged portion 8-2-2. On the other hand, in the downstream region 7, the second surface 5 extends in an inclined manner. Even if such a configuration is adopted, the same effect as in the present embodiment can be obtained.

  FIG. 10 is a schematic view showing a scramjet engine 11 according to a third modification of the present embodiment. In the present modification, the first surface 4 extends in an inclined manner in the cross-sectional area enlarged portion 8-2-2. Moreover, in the downstream area | region 7, both the 1st surface 4 and the 2nd surface 5 are inclined and extended so that a cross-sectional area may expand, so that it goes to the back side. Even if the configuration as in this modification is employed, the same effect as in the present embodiment can be obtained.

  The present invention has been described above using the first and second embodiments. It should be noted that the above-described embodiment and modification examples are not independent and can be used in combination within a consistent range.

DESCRIPTION OF SYMBOLS 1 Airframe 2 Cowl 3 Air flow path 4 1st surface 5 2nd surface 6 Fuel supply area 6-1 Supply area front part 6-2 Supply area rear part 7 Downstream area 8 Upstream area 8-1 Reduced diameter part 8-2 Connection Part 8-2-1 Cross-sectional area constant part 8-2-2 Cross-sectional area enlarged part 9 Fuel supply mechanism 10 Cavity (concave part)
11 Scramjet engine 100 Scramjet engine 101 Airframe 102 Cowl (flow path forming member)
103 air flow path 104 fuel supply mechanism

Claims (5)

An air flow path forming member attached to the fuselage so that an air flow path is formed;
A fuel supply mechanism for supplying fuel into the air flow path;
Comprising
The air flow path is formed to connect a front opening provided on the front side and a rear opening provided on the rear side,
The air flow path is
An upstream region that takes in air through the front opening during supersonic flight; and
A fuel supply region that is connected to the rear side of the upstream region, is supplied with the fuel, and the captured air burns to generate combustion gas; and
A downstream region connected to a rear side of the fuel supply region and ejecting the combustion gas through the rear opening;
The fuel supply area is
A supply area front portion provided on the front side;
A supply area rear portion provided on the rear side,
The downstream region is formed such that the cross-sectional area increases toward the rear side,
A scramjet engine in which the amount of increase in cross-sectional area per unit length in the downstream region is larger than that in the front portion of the supply region. A scramjet engine according to claim 1,
The side wall in the fuel region rear portion is provided with a recess,
The fuel supply mechanism is a scramjet engine configured to inject the fuel into the air flow path from the recess. A scramjet engine according to claim 2,
The recess is a scramjet engine provided in the airframe. A scramjet engine according to any one of claims 1 to 3,
The upstream region has a cross-sectional area enlarged portion provided adjacent to the fuel supply region,
The cross-sectional area enlarged portion is a scramjet engine formed so that a cross-sectional area increases toward the rear side. A scramjet engine according to any one of claims 1 to 4,
The aircraft has a first surface,
The air flow path forming member includes a second surface, and is attached to the airframe so as to face the first surface at the second surface,
The air flow path is formed between the first surface and the second surface,
An angle formed by the first surface and the second surface is defined as an opening angle,
A scramjet engine in which an opening angle in the downstream region is larger than an opening angle in a front portion of the fuel region.

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