A short-distance and high-efficiency ram combustion chamber based on cracking gas ejector pressurization

Abstract

The present invention discloses a short-distance and high-efficiency ram combustion chamber based on pyrolysis gas ejection and pressurization, comprising: an isolation tube, a combustion chamber, and a central support plate which is a V-shaped thin-walled member and is vertically arranged with the V-shaped opening facing the isolation tube. The central support plate is composed of an upper support plate and a lower support plate which are integrally connected. The upper support plate is on the upper side of the lower support plate. The lower end of the upper support plate is integrally connected to the upper end of the lower support plate and they cooperate with each other to form a V-shaped opening. Among them, a gas passage and a liquid passage are provided on the central support plate. Both the gas passage and the liquid passage are arranged along their respective directions from the upper end and the lower end of the central support plate. The liquid passage is used for liquid kerosene to pass through and enter the combustion chamber, and the gas passage is used for pyrolysis gas to pass through, gather, expand and accelerate and then enter the combustion chamber; the present invention ejects pyrolysis gas from the pyrolysis gas ejection groove at the rear end of the support plate, realizing an effect similar to an ejector jet, and can further enhance and regulate the combustion heat release process of the fuel, thereby enhancing the combustion heat release capacity of the fuel.

Description

Technical Field

[0001] The present invention belongs to the field of ramjet engines, and particularly relates to a short-distance and high-efficiency ramjet combustion chamber based on cracked gas ejector pressurization. Background Art

[0002] A ramjet engine is an air-breathing jet engine that operates by the deceleration and pressurization of high-speed oncoming air flow. A ramjet engine utilizes the high-temperature gas generated by the deceleration, pressurization, and temperature increase of high-speed air flow in the intake duct and then entering the combustion chamber to mix with fuel and burn, and generates thrust through the expansion and acceleration of the gas in the nozzle.

[0003] A ramjet engine can directly use air as an oxidant, which can significantly reduce the mass of the engine and increase the thrust-to-weight ratio. Compared with a rocket engine, a ramjet engine has a higher specific impulse and better economy; compared with a turbojet engine, a ramjet engine generates greater thrust during high-speed flight, is not restricted by the cooling problem of rotating components, and allows a higher combustion temperature in the combustion chamber. Therefore, ramjet engines have good application prospects.

[0004] In the actual working process of a ramjet engine, it is necessary to meet the working performance requirements in a wide speed range. However, wide-range ramjet engines mainly face the problems of low mixing combustion efficiency, long combustion heat release interval, and large heat load. In order to enhance the combustion heat release capacity of fuel, increase the thrust-to-weight ratio of the engine, and reduce the difficulty of thermal protection, it is necessary to further increase the fuel mixing efficiency, shorten the combustion interval, and reduce the thermal protection cooling area on the basis of existing combustion organization technologies. Therefore, it is necessary to carry out research on wide-range short-distance and low-heat-load high-efficiency combustion organization technologies, which is of great significance for the further development of aerospace power devices. Summary of the Invention

[0005] The purpose of the present invention is to provide a short-distance and high-efficiency ramjet combustion chamber based on cracked gas ejector pressurization to solve the problems of low mixing combustion efficiency, long combustion heat release interval, and large heat load.

[0006] The present invention adopts the following technical solutions: A short-distance and high-efficiency ramjet combustion chamber based on cracked gas ejector pressurization, comprising:

[0007] An isolation tube, which is a hollow tube body with a rectangular cross-section, and its front end is connected to the rear end of the engine intake duct.

[0008] A combustion chamber, which is a hollow tube body and coincides with the axis of the isolation tube, and its front end is connected to the rear end of the isolation tube.

[0009] The central support plate is located between the front inner cavity of the combustion chamber tube body and the rear cavity of the isolation tube. It is a V-shaped thin-walled part, vertically arranged, with the opening of its V shape facing the isolation tube. The central support plate is composed of an upper support plate and a lower support plate connected integrally. The upper support plate is on the upper side of the lower support plate. The lower end of the upper support plate is integrally connected to the upper end of the lower support plate and they cooperate with each other to form a V-shaped opening.

[0010] Among them, a gas passage and a liquid passage are opened on the central support plate. Both the gas passage and the liquid passage are arranged along its trend from the upper end and the lower end of the central support plate. The liquid passage is used for liquid kerosene to pass through and enter the combustion chamber. The gas passage is used for cracked gas to pass through, gather, expand and accelerate, and then enter the combustion chamber.

[0011] Furthermore, the liquid passage includes:

[0012] The upper liquid kerosene holes opened downward along the trend of the upper support plate inside the wall of the upper support plate. The upper liquid kerosene holes are inclined. A plurality of upper dispersion holes which are blind holes are also opened on the side wall of the upper support plate. The axes of the plurality of upper dispersion holes are perpendicular to the axis of the upper liquid kerosene hole. Each upper dispersion hole is communicated with the upper liquid kerosene hole. Each upper dispersion hole is used for liquid kerosene to be sprayed into the combustion chamber after passing through the upper liquid kerosene hole from the external kerosene pipeline and then through the upper dispersion hole.

[0013] Furthermore, the liquid passage also includes:

[0014] The lower liquid kerosene holes opened upward along the trend of the lower support plate inside the wall of the lower support plate. The lower liquid kerosene holes are inclined. A plurality of lower dispersion holes which are blind holes are also opened on the side wall of the lower support plate. The axes of the plurality of lower dispersion holes are perpendicular to the axis of the liquid kerosene hole. Each lower dispersion hole is communicated with the lower liquid kerosene hole. Each lower dispersion hole is used for liquid kerosene to be sprayed into the combustion chamber after passing through the lower liquid kerosene hole from the external kerosene pipeline and then through the lower dispersion hole.

[0015] Furthermore, the gas passage includes:

[0016] The upper cracked gas holes opened downward along the trend of the upper support plate on the upper support plate. The upper cracked gas holes are inclined. The upper cracked gas holes are used for cracked gas to enter.

[0017] The gathering holes are also opened inside the wall of the upper support plate. The gathering holes are located at the lower end of the upper cracked gas holes and are communicated with the upper cracked gas holes. The gathering holes are used for gathering the cracked gas entering through the upper cracked gas holes.

[0018] The cracked gas ejection grooves opened forward at the rear end of the upper support plate. The cracked gas ejection grooves are used for expanding and accelerating the cracked gas in the gathering holes and then sending it to the combustion chamber.

[0019] Furthermore, the gas passage also includes:

[0020] On the lower support plate, there are also lower cracking air holes opened upward from its lower end along the direction of the lower support plate. The lower cracking air holes are inclined and used for the entry of cracking gas.

[0021] The aggregation holes are located at the lower end of the upper cracking air holes and the upper end of the lower cracking air holes, and are communicated with the upper cracking air holes and the lower cracking air holes. Thus, the cracking gas ejection groove expands and accelerates the cracking gas in the aggregation holes and then sends it to the combustion chamber.

[0022] Furthermore, the upper cracking air holes are parallel to the upper liquid kerosene holes. Upper dispersion holes are opened on both the left side wall and the right side wall of the upper support plate, and lower dispersion holes are opened on both the left side wall and the right side wall of the lower support plate.

[0023] Furthermore, both the upper end and the lower end of the central support plate are fixed to the outer wall of the engine through horizontally arranged connecting plates. There are multiple central support plates and they are arranged side by side.

[0024] Furthermore, the front end of the combustion chamber bulges upward and downward to form a combustion section. The central support plate is located within the combustion section, and the combustion section is used for the combustion of liquid kerosene under the action of cracking gas.

[0025] The cross-section of the combustion chamber is rectangular, and the cross-section from front to back gradually increases within the combustion section and first decreases and then gradually increases between the combustion sections.

[0026] Furthermore, it also includes a nozzle. The front end of the nozzle is connected to the rear end of the combustion chamber, and the cross-section of the nozzle outlet is circular; the cross-section of the nozzle gradually changes from rectangular to circular from front to back.

[0027] Furthermore, the cross-sectional area of the aggregation holes gradually decreases from front to back, and the cross-sectional area of the cracking gas ejection groove gradually increases from front to back.

[0028] The beneficial effects of the present invention are as follows: By ejecting cracking gas from the cracking gas ejection groove at the rear end of the support plate, the present invention realizes an effect similar to an ejector jet, which can further enhance the regulation of the heat release process of fuel combustion, thereby enhancing the heat release ability of fuel combustion; moreover, the liquid kerosene fuel is ejected from the dispersion holes on both sides of the support plate, and central combustion is formed by using the short delay time of cracking gas, which can further shorten the combustion interval, thereby reducing the length of the engine and the structural mass of the engine; shortening the combustion interval also reduces the heat protection cooling area, thereby reducing the difficulty of heat protection, and can also reduce the heat protection cooling area, thereby reducing the difficulty of heat protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural schematic diagram of the present invention;

[0030] Figure 2 is a cross-sectional view of the present invention;

[0031] Figure 3 Schematic structural diagram of the central support plate of the present invention;

[0032] Figure 4 Cross-sectional view of the central support plate of the present invention;

[0033] Figure 5 Mach number distribution nephogram of Embodiment 1 of the present invention;

[0034] Figure 6 Static pressure distribution nephogram of Embodiment 1 of the present invention;

[0035] Figure 7 Static temperature distribution nephogram of Embodiment 1 of the present invention.

[0036] Wherein: 1. Isolation tube; 2. Combustion chamber; 3. Central support plate; 4. Upper support plate; 5. Lower support plate; 6. Upper liquid kerosene hole; 7. Upper dispersion hole; 8. Upper cracking gas hole; 9. Aggregation hole; 10. Cracking gas ejection groove; 11. Lower dispersion hole; 12. Lower cracking gas hole; 13. Nozzle. Detailed implementation manners

[0037] The present invention will be described in detail below with reference to the accompanying drawings and specific implementation manners.

[0038] The present invention discloses a short-distance and high-efficiency ram combustion chamber based on cracking gas ejector boosting, as Figures 1-4 shown, including an isolation tube 1, a combustion chamber 2, and a central support plate 3.

[0039] The isolation tube 1 is a hollow tube body, the cross-section of the isolation tube 1 is rectangular, the front end of the isolation tube 1 is connected to the rear end of the engine intake duct, the combustion chamber 2 is a hollow tube body and coincides with the axis of the isolation tube 1, the front end of the combustion chamber 2 is connected to the rear end of the isolation tube 1, the central support plate 3 is located between the front inner cavity of the combustion chamber 2 tube body and the rear cavity of the isolation tube 1, the central support plate 3 is a V-shaped thin-walled part, the central support plate 3 is vertically arranged, and the opening of the V shape of the central support plate 3 faces the isolation tube 1.

[0040] The central support plate 3 is composed of an upper support plate 4 and a lower support plate 5 which are integrally connected. The upper support plate 4 is on the upper side of the lower support plate 5. The lower end of the upper support plate 4 is integrally connected to the upper end of the lower support plate 5 and cooperates with each other to form a V-shaped opening. The central support plate 3 is provided with a gas passage and a liquid passage. Both the gas passage and the liquid passage are arranged along their directions from the upper end and the lower end of the central support plate 3. The liquid passage is used for liquid kerosene to pass through and enter the combustion chamber 2, and the gas passage is used for cracking gas to pass through, and after gathering, expanding and accelerating, it enters the combustion chamber 2.

[0041] The liquid passage includes: an upper liquid kerosene hole 6 opened downward from the upper end along the direction of the upper support plate 4 within the wall of the upper support plate 4. The upper liquid kerosene hole 6 is inclined. A plurality of upper dispersion holes 7 which are blind holes are also opened on the side wall of the upper support plate 4. The axes of the plurality of upper dispersion holes 7 are perpendicular to the axis of the liquid kerosene hole. Each upper dispersion hole 7 is communicated with the upper liquid kerosene hole 6. Each upper dispersion hole 7 is used for liquid kerosene to be sprayed into the combustion chamber 2 from the external kerosene pipeline through the upper liquid kerosene hole 6 and then through the upper dispersion hole 7.

[0042] The liquid passage also includes: a lower liquid kerosene hole opened upward from the lower end along the direction of the lower support plate 5 within the wall of the lower support plate 5. The lower liquid kerosene hole is inclined. A plurality of lower dispersion holes 11 which are blind holes are also opened on the side wall of the lower support plate 5. The axes of the plurality of lower dispersion holes 11 are perpendicular to the axis of the liquid kerosene hole. Each lower dispersion hole 11 is communicated with the lower liquid kerosene hole. Each lower dispersion hole 11 is used for liquid kerosene to be sprayed into the combustion chamber 2 from the external kerosene pipeline through the lower liquid kerosene hole and then through the lower dispersion hole 11.

[0043] The lower end of the upper liquid kerosene hole 6 and the upper end of the lower liquid kerosene hole are communicated with each other. After such a setting, liquid kerosene can enter only from the upper end of the upper liquid kerosene hole 6 or the lower end of the lower liquid kerosene hole, reducing the porosity of the entire combustion chamber.

[0044] The gas passage includes: an upper cracking gas hole 8 opened downward from the upper end along the direction of the upper support plate 4 on the upper support plate 4. The upper cracking gas hole 8 is inclined. The upper cracking gas hole 8 is used for cracking gas to enter. An aggregation hole 9 is also opened within the wall of the upper support plate 4. The aggregation hole 9 is located at the lower end of the upper cracking gas hole 8 and is communicated with the upper cracking gas hole 8. The aggregation hole 9 is used for aggregating the cracking gas entering through the upper cracking gas hole 8. A cracking gas ejection groove 10 is opened forward at the rear end of the upper support plate 4. The cracking gas ejection groove 10 is used for expanding and accelerating the cracking gas in the aggregation hole 9 to the combustion chamber 2. The upper cracking gas hole 8 and the upper liquid kerosene hole 6 are parallel to each other.

[0045] The gas passage also includes: a lower cracking gas hole 12 opened upward from the lower end along the direction of the lower support plate 5 on the lower support plate 5. The lower cracking gas hole 12 is inclined. The lower cracking gas hole 12 is used for cracking gas to enter. The aggregation hole 9 is located at the lower end of the upper cracking gas hole 8 and the upper end of the lower cracking gas hole 12 and is communicated with the upper cracking gas hole 8 and the lower cracking gas hole 12. In this way, a certain amount of cracking gas can be aggregated, thus having a certain pressure energy.

[0046] Upper dispersion holes 7 are opened on both the left side wall and the right side wall of the upper support plate 4, and lower dispersion holes 11 are opened on both the left side wall and the right side wall of the lower support plate 5. This can ensure that the kerosene is distributed more evenly in the cross-section of the combustion chamber 2 when being sprayed into the combustion chamber 2, thus ensuring the uniform mixing of kerosene and the oncoming air.

[0047] The upper and lower ends of the central support plate 3 are both fixed on the outer wall of the engine through horizontally arranged connecting plates. A plurality of central support plates 3 are provided and arranged side by side. The front end of the combustion chamber 2 bulges upward and downward to form a combustion section. The central support plate 3 is located within the combustion section, and the combustion section is used for the combustion of liquid kerosene under the action of cracked gas. The cross-section of the combustion chamber 2 is rectangular, and the cross-section from front to back gradually increases in the combustion section and first decreases and then gradually increases between the combustion sections.

[0048] The present invention further includes a nozzle 13. The front end of the nozzle 13 is communicated with the rear end of the combustion chamber 2, and the cross-section of the outlet of the nozzle 13 is circular. The cross-section of the nozzle 13 gradually changes from rectangular to circular from front to back.

[0049] The converging holes 9 gradually decrease in area from front to back, and the cracked gas ejection grooves 10 gradually increase in area from front to back. The converging holes 9 and the cracked gas ejection grooves 10 form a Laval nozzle 13 to accelerate the cracked gas, that is, to convert the pressure energy of the cracked gas into kinetic energy.

[0050] The cracked gas of the present invention is introduced into the converging holes 9 and the cracked gas ejection grooves 10 of the central support plate 3, thereby realizing an effect similar to an ejector jet. It can not only improve the anti-backpressure ability of the engine isolation section to a certain extent, but also shorten the distance of combustion heat release. Therefore, the required length of the isolation section can be shortened, and thus the structural mass of the engine can be reduced. The liquid kerosene fuel is considered to be injected from both sides of the central support plate 3, and then the short ignition delay time of the cracked gas is utilized to form central combustion, reducing the wall heat load, and effectively reducing the difficulty of thermal protection.

[0051] Embodiment 1

[0052] As Figures 5-7 For the Mach number, static pressure and static temperature distribution obtained from the numerical simulation calculation of the short-distance, low-heat-load, and high-efficiency combustion organization combustion chamber 2 scheme adopting the high-temperature cracked gas jet and plasma jet scheme. It can be seen that under the action of the cracked gas jet, although the length of the isolation tube 1 is reduced, the combustion chamber 2 and the isolation tube 1 can still operate normally under the condition of 0.8 equivalence ratio. In addition, it can be seen from the temperature distribution cloud map that under the action of the cracked gas jet, the main heat release area of the combustion chamber 2 is distributed in the middle position of the flow channel, and there is a relatively obvious low-temperature area near the wall surface. It can be seen that the central combustion method with high-enthalpy cracked gas has great advantages.

[0053] For the combustion chamber 2 scheme with short-distance and low heat load using high-enthalpy pyrolysis gas jet combined with plasma, through preliminary simulation calculations, it can be obtained that when the combustion chamber 2 operates under the Ma3 incoming flow condition and the injection equivalence ratio is set to 0.8, a thrust of 9570 N can be obtained and a specific impulse of 1395 s can be achieved. Therefore, by adopting a new fuel cycle injection method combined with plasma combustion assistance, the engine length can be shortened by 30%.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A short - distance and high - efficiency ram combustion chamber based on cracking gas ejector pressurization, characterized in that, it includes: An isolation tube (1), which is a hollow tube body with a rectangular cross - section, and its front end is connected to the rear end of the engine intake duct, A combustion chamber (2), which is a hollow tube body and coincides with the axis of the isolation tube (1), and its front end is connected to the rear end of the isolation tube (1), A central support plate (3), which is located between the front - end inner cavity of the combustion chamber (2) tube body and the rear - end cavity of the isolation tube (1), is a V - shaped thin - walled part, vertically arranged, with the opening of its V - shape facing the isolation tube (1). The central support plate (3) is composed of an upper support plate (4) and a lower support plate (5) connected integrally. The upper support plate (4) is on the upper side of the lower support plate (5). The lower end of the upper support plate (4) is integrally connected to the upper end of the lower support plate (5) and they cooperate with each other to form a V - shaped opening, wherein, gas passages and liquid passages are provided on the central support plate (3). Both the gas passages and the liquid passages are arranged along its trend from the upper end and the lower end of the central support plate (3). The liquid passage is used for liquid kerosene to pass through and enter the combustion chamber (2), and the gas passage is used for cracking gas to pass through, gather, expand and accelerate and then enter the combustion chamber (2); The liquid passage includes: An upper liquid kerosene hole (6) opened downward along the trend of the upper support plate (4) from its upper end inside the wall of the upper support plate (4). The upper liquid kerosene hole (6) is inclined. A plurality of upper dispersion holes (7) which are blind holes are also opened on the side wall of the upper support plate (4). The axes of the plurality of upper dispersion holes (7) are perpendicular to the axis of the upper liquid kerosene hole (6). Each of the upper dispersion holes (7) is communicated with the upper liquid kerosene hole (6). Each of the upper dispersion holes (7) is used for liquid kerosene to be sprayed into the combustion chamber (2) from the external kerosene pipeline through the upper liquid kerosene hole (6) and then through the upper dispersion holes (7); A cracking gas ejection groove (10) opened forward at the rear end of the upper support plate (4).

2. The short - distance and high - efficiency ram combustion chamber based on cracking gas ejector pressurization according to claim 1, characterized in that, The liquid passage further includes: A lower liquid kerosene hole opened upward along the trend of the lower support plate (5) from its lower end inside the wall of the lower support plate (5). The lower liquid kerosene hole is inclined. A plurality of lower dispersion holes (11) which are blind holes are also opened on the side wall of the lower support plate (5). The axes of the plurality of lower dispersion holes (11) are perpendicular to the axis of the liquid kerosene hole. Each of the lower dispersion holes (11) is communicated with the lower liquid kerosene hole. Each of the lower dispersion holes (11) is used for liquid kerosene to be sprayed into the combustion chamber (2) from the external kerosene pipeline through the lower liquid kerosene hole and then through the lower dispersion holes (11).

3. The short - distance and high - efficiency ram combustion chamber based on cracking gas ejector pressurization according to claim 2, characterized in that, The gas passage includes: An upper cracking gas hole (8) opened downward along the trend of the upper support plate (4) from its upper end on the upper support plate (4). The upper cracking gas hole (8) is inclined. The upper cracking gas hole (8) is used for cracking gas to enter, An aggregation hole (9) is also formed in the wall of the upper support plate (4). The aggregation hole (9) is located at the lower end of the upper cracking gas hole (8) and communicates with the upper cracking gas hole (8). The aggregation hole (9) is used for aggregating the cracking gas entering through the upper cracking gas hole (8).

4. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 3, characterized in that, the gas passage further includes: a lower cracking gas hole (12) formed on the lower support plate (5) and extending upward along the direction of the lower support plate (5) from its lower end. The lower cracking gas hole (12) is inclined and is used for the entry of cracking gas, the aggregation hole (9) is located at the lower end of the upper cracking gas hole (8) and the upper end of the lower cracking gas hole (12), and communicates with the upper cracking gas hole (8) and the lower cracking gas hole (12), so that the cracking gas ejection groove (10) expands and accelerates the cracking gas in the aggregation hole (9) and then sends it to the combustion chamber (2).

5. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 4, characterized in that, the upper cracking gas hole (8) is parallel to the upper liquid kerosene hole (6). Upper dispersion holes (7) are formed on both the left and right side walls of the upper support plate (4), and lower dispersion holes (11) are formed on both the left and right side walls of the lower support plate (5).

6. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 5, characterized in that, both the upper end and the lower end of the central support plate (3) are fixed to the outer wall of the engine through horizontally arranged connecting plates. A plurality of central support plates (3) are provided and arranged in parallel.

7. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 6, characterized in that, the front end of the combustion chamber (2) bulges upward and downward to form a combustion section. The central support plate (3) is located in the combustion section. The combustion section is used for the combustion of liquid kerosene under the action of cracking gas; the cross-section of the combustion chamber (2) is rectangular, and the cross-section from front to back gradually increases in the combustion section and first decreases and then gradually increases between the combustion sections.

8. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 7, characterized in that, it further includes a nozzle (13). The front end of the nozzle (13) is communicated with the rear end of the combustion chamber (2). The cross-section of the outlet of the nozzle (13) is circular; the cross-section of the nozzle (13) gradually changes from rectangular to circular from front to back.

9. A short-distance high-efficiency ram combustion chamber based on cracking gas injection and boosting according to claim 8, characterized in that, the cross-sectional area of the aggregation hole (9) gradually decreases from front to back, and the cross-sectional area of the cracking gas ejection groove (10) gradually increases from front to back.

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