A structure of a porous transverse jet mixing afterburner for a powder fuel ramjet engine

Abstract

The application discloses a kind of powder fuel ramjet porous transverse jet mixing afterburning chamber structure, including afterburning chamber outer cylinder, flame tube, flame stabilizer and the front support plate and rear support plate of connecting afterburning chamber outer cylinder and flame tube;Annular flow passage head between afterburning chamber outer cylinder and flame tube is connected with inlet duct outlet, is ram air flow passage;Air inlet hole is arranged on the wall surface of flame tube, for ram air from outside annular flow passage enters combustion zone in flame tube in multiple times;Half-cylinder flame stabilizer is arranged on the last row air inlet hole upstream of the inner side of flame tube wall, for stabilizing flame, and using the low pressure area downstream of it, increase ram air jet depth.The application is simple in structure, scientific and reasonable, can effectively enhance the mixing combustion of powder fuel, high-temperature gas and ram air, and is suitable for powder fuel ramjet.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of powder fuel ramjet engine, and relates to a porous transverse jet mixing afterburning chamber structure of a powder fuel ramjet engine. BACKGROUND

[0002] With the increasingly fierce attack and defense confrontation in the aerospace field, the next generation of missile weapon systems develop towards large airspace, wide speed domain, strong maneuvering, high stealth, long range, and require the power device to have high energy, normal work in large airspace multi-trajectory, fast reaction speed, small volume, light mass, easy maintenance and use, and good storage performance. Compared with rocket engines, ramjet engines do not need to carry oxidizers, have more excellent specific impulse performance, and have a very wide application prospect in the military field. The powder fuel ramjet engine has the advantages of simple structure, high reliability, easy maintenance and use, and the advantages of multiple start-up and adjustable thrust of liquid ramjet engines. Moreover, the combustion products of solid particle fuel are not easy to dissociate and absorb heat in a high temperature environment, and have good heat release performance, which meets the needs of future supersonic missiles for power devices. Therefore, the powder fuel ramjet engine has become an important development direction of future missile propulsion systems.

[0003] Efficient combustion of powder fuel is the premise and basis of efficient heat release of powder fuel in the afterburning chamber, and is the key to realizing large thrust and high specific impulse of the powder fuel ramjet engine. However, compared with liquid hydrocarbon fuel, the melting point and boiling point of powder fuel are higher, the inertia of powder particles is large, and the mixing with airflow is more difficult, so it faces not small challenges to realize efficient combustion of powder fuel in the afterburning chamber. The current commonly used annular axial inlet and double lower side inlet face the following problems when the engine diameter increases and the total pressure of the ram airflow is low in high altitude flight: 1) the penetration depth of the ram air is insufficient, and it is not easy to realize uniform mixing of powder fuel, high-temperature gas and ram air; 2) the inlet is concentrated, and the contact area of powder fuel, high-temperature gas and ram air is limited, which is not conducive to further improving the combustion rate; 3) the large-scale vortex in the flow field will enhance the non-uniformity and non-stationarity of the flow parameters of the gas at the outlet of the afterburning chamber. These deficiencies seriously affect the improvement of the combustion efficiency of the powder fuel ramjet engine afterburning chamber, and restrict the performance of the powder fuel ramjet engine thrust and specific impulse. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a porous transverse jet mixing afterburning chamber structure of a powder fuel ramjet engine to solve the problems of low combustion efficiency of the powder fuel ramjet engine afterburning chamber, insufficient thrust and specific impulse performance of the powder fuel ramjet engine, and the like.

[0005] In order to solve the above technical problems, the present application adopts the following technical solutions to achieve it:

[0006] A kind of powder fuel ramjet porous transverse jet mixing afterburning chamber structure, including afterburning chamber outer cylinder, flame tube, powder fuel nozzle, gas generator nozzle, front support plate, rear support plate, flame stabilizer and afterburning chamber nozzle;

[0007] The afterburning chamber outer cylinder is covered outside the flame tube, and the annular flow passage between the afterburning chamber outer cylinder and the flame tube is a ram air flow passage, and the afterburning chamber outer cylinder and the flame tube are supported and connected by a plurality of front support plates and rear support plates;

[0008] The front end surface of the flame tube is provided with a powder fuel nozzle and a gas generator nozzle;The sidewall of the flame tube is provided with a plurality of air inlet holes to allow ram air to enter the combustion zone of the flame tube in multiple times from the annular flow passage;

[0009] The flame stabilizer is arranged on the inner wall of the flame tube in a circumferential direction and is located upstream of the air inlet hole in the rear part of the flame tube;

[0010] The afterburning chamber nozzle is butted against the rear end of the afterburning chamber outer cylinder;

[0011] The diameter of the afterburning chamber outer cylinder is D1, and the length is L1;The diameter of the flame tube is D2, and the length is L2.

[0012] The present application also includes the following technical features:

[0013] Specifically, the air inlet holes in the sidewall of the flame tube are divided into four rows, and the number and diameter of the four rows of air inlet holes are different;From the front end of the flame tube to the rear end, they are the first row of air inlet holes, the second row of air inlet holes, the third row of air inlet holes and the fourth row of air inlet holes.

[0014] Specifically, the number of the first row of air inlet holes is n1, and the diameter is d1, the first row of air inlet holes is uniformly distributed in the circumferential direction, the axial distance from the first row of air inlet holes to the head of the flame tube is l1, and it satisfies 4 < n1 < 16, 0.1D2 < l1 < 0.3D2.

[0015] Specifically, the number of the second row of air inlet holes is 2, and the diameter is d2, the circumferential angle of the second row of air inlet holes is α, the axial distance from the second row of air inlet holes to the center of the first row of air inlet holes is l2, and it satisfies 75° < α < 105°, 0.2D2 < l2 < 0.3D2.

[0016] Specifically, the number of the third row of air inlet holes is 2, and the diameter is d3, the circumferential angle of the third row of air inlet holes is α, the axial distance from the third row of air inlet holes to the center of the second row of air inlet holes is l3, and it satisfies 0.2D2 < l3 < 0.3D2;The circumferential position of the third row of air inlet holes is obtained by counterclockwise rotation of the second row of air inlet holes by 180°.

[0017] Specifically, the fourth row of air inlet holes has a number n4, a hole diameter d4, and are uniformly arranged in a circumference, and the axial distance between the center of the fourth row of air inlet holes and the third row of air inlet holes is l4, and 4 < n4 < 16, 0.1D2 < l4 < 0.3D2.

[0018] Specifically, the front edges of the front support plates are aligned with the front end of the outer cylinder of the afterburner and the front end face of the flame tube, and a plurality of front support plates are uniformly distributed in the circumference; the rear edges of the rear support plates are aligned with the rear end face of the flame tube, and a plurality of rear support plates are uniformly distributed in the circumference.

[0019] The front support plates are welded with the outer cylinder of the afterburner and the flame tube; the rear support plates are welded with the outer cylinder of the afterburner and the flame tube.

[0020] Specifically, the powder fuel nozzle is located at the center of the front end face of the flame tube; the gas generator nozzle has a plurality of and is arranged around the powder fuel nozzle; the powder fuel is carried by the fluidizing gas in the form of gas-solid two-phase flow into the flame tube through the powder fuel nozzle; and the high-temperature gas is injected into the flame tube at high speed through the gas generator nozzle.

[0021] Specifically, the flame stabilizer is welded to the inner wall of the flame tube and located upstream of the fourth row of air inlet holes; the flame stabilizer is connected with the front half side of the hole edge of the fourth row of air inlet holes.

[0022] Specifically, the flame stabilizer is a semi-cylindrical structure, the diameter of the flame stabilizer is d4, the length is l5, and 0.1D2 < l5 < 0.2D2.

[0023] Compared with the prior art, the present application has the following technical effects:

[0024] By arranging the flame stabilizer upstream of the air inlet hole, the present application can significantly increase the depth of the ram air jet, strengthen the mixing of the rich combustion gas and air upstream of the flame tube outlet, effectively solve the problem that the ram air is difficult to penetrate into the central combustion core area of the flame tube, and realize uniform mixing.

[0025] By designing the multi-hole transverse jet structure and reasonably arranging the flame stabilizer, the present application can effectively shorten the penetration distance required by the ram air, increase the jet depth, increase the contact area with the powder fuel and high-temperature gas, and thus significantly improve the combustion rate of the powder fuel in the afterburner.

[0026] By arranging the second and third rows of air inlet holes symmetrically about the center of the engine section in the circumference, opposite rotating vortices are generated and superimposed, which can significantly reduce the vortex intensity; by combining the fourth row of air inlet holes arranged uniformly in the circumference with the flame stabilizer, the upstream large-scale vortex is broken into a small-scale vortex, which can significantly reduce the non-uniformity and non-constancy of the flow parameters at the outlet of the afterburner. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1This is a schematic diagram of the porous transverse jet combustion chamber of the powder fuel ramjet engine of the present invention.

[0028] Figure 2 This is a half-section view of the flame tube.

[0029] Figure 3 This is a cross-sectional view of the flame tube at section AA.

[0030] Figure 4 This is a cross-sectional view of the flame tube at section BB.

[0031] Figure 5 This is a cross-sectional view of the flame tube at section CC.

[0032] Figure 6 This is a cross-sectional view of the afterburner chamber at section CC.

[0033] The meanings of the labels in the diagram are as follows:

[0034] 1. Afterburner outer cylinder, 2. Flame tube, 3. Powder fuel nozzle, 4. Gas generator nozzle, 5. Front support plate, 6. Rear support plate, 7. Flame stabilizer, 8. Afterburner nozzle. Detailed Implementation

[0035] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0036] Example 1:

[0037] like Figures 1 to 6 As shown, this embodiment provides a porous transverse jet mixing afterburner structure for a powder fuel ramjet engine, including an outer cylinder 1, a flame tube 2, a powder fuel nozzle 3, a gas generator nozzle 4, a front support plate 5, a rear support plate 6, a flame stabilizer 7, and an afterburner nozzle 8.

[0038] The outer combustion chamber 1 is fitted outside the flame tube 2. The annular flow channel between the outer combustion chamber 1 and the flame tube 2 serves as a ram air flow channel. The outer combustion chamber 1 and the flame tube 2 are supported and connected by multiple front support plates 5 and rear support plates 6. The front end face of the flame tube 2 is equipped with a powder fuel nozzle 3 and a gas generator nozzle 4. The side wall of the flame tube 2 is provided with multiple air inlets to allow ram air to enter the combustion zone of the flame tube 2 multiple times from the annular flow channel. The flame stabilizer 7 is arranged circumferentially on the inner wall of the flame tube 2 and is located upstream of the air inlet at the rear of the flame tube 2. Figure 1 The left / front end of the fourth row of air intake holes; the afterburner nozzle 8 is connected to the rear end of the afterburner outer cylinder 1; the diameter of the afterburner outer cylinder 1 is D1 and the length is L1; the diameter of the flame tube 2 is D2 and the length is L2.

[0039] The side wall air inlet holes of the flame tube 2 are divided into four rows, and the number and diameter of the air inlet holes in the four rows are different; from the front end to the rear end of the flame tube 2, the first row of air inlet holes, the second row of air inlet holes, the third row of air inlet holes and the fourth row of air inlet holes are arranged in sequence.

[0040] The number of the first row of air inlet holes is n1, the diameter is d1, the first row of air inlet holes is uniformly distributed in the circumferential direction, the axial distance of the first row of air inlet holes to the head of the flame tube 2 is l1, and it satisfies 4 < n1 < 16, 0.1D2 < l1 < 0.3D2. d1 is determined according to the primary air flow and n1.

[0041] The number of the second row of air inlet holes is 2, the diameter is d2, the circumferential angle of the second row of air inlet holes is a, the axial distance l2 of the second row of air inlet holes to the center of the first row of air inlet holes, and it satisfies 75° < a < 105°, 0.2D2 < l2 < 0.3D2. d2 is determined according to the secondary air flow.

[0042] The number of the third row of air inlet holes is 2, the diameter is d3, the circumferential angle of the third row of air inlet holes is a, the axial distance l3 of the third row of air inlet holes to the center of the second row of air inlet holes, and it satisfies 0.2D2 < l3 < 0.3D2; the circumferential position of the third row of air inlet holes is obtained by rotating the second row of air inlet holes counterclockwise by 180°, and d3 is determined according to the tertiary air flow.

[0043] The number of the fourth row of air inlet holes is n4, the diameter is d4, the fourth row of air inlet holes is uniformly arranged in the circumferential direction, the axial distance l4 of the fourth row of air inlet holes to the center of the third row of air inlet holes, and it satisfies 4 < n4 < 16, 0.1D2 < l4 < 0.3D2. d4 is determined according to the fourth air flow and n4.

[0044] The four diameters d1, d2, d3 and d4 are determined by the air flow, in this embodiment, the diameters of the second row of air inlet holes and the third row of air inlet holes are greater than the diameters of the first row of air inlet holes and the fourth row of air inlet holes.

[0045] The front edges of the front support plates 5 are aligned with the front end of the afterburning chamber outer cylinder 1 and the front end face of the flame tube 2, and a plurality of front support plates 5 are uniformly distributed in the circumferential direction; the rear edges of the rear support plates 6 are aligned with the rear end face of the flame tube 2, and a plurality of rear support plates 6 are uniformly distributed in the circumferential direction; the front support plates 5 are welded to the afterburning chamber outer cylinder 1 and the flame tube 2; the rear support plates 6 are welded to the afterburning chamber outer cylinder 1 and the flame tube 2.

[0046] The powder fuel nozzle 3 is located at the center of the front end face of the flame tube 2; the gas generator nozzle 4 has a plurality of gas generator nozzles and is arranged around the powder fuel nozzle 3; the powder fuel is carried by the fluidizing gas in the form of gas-solid two-phase flow into the flame tube 2 through the powder fuel nozzle 3; the high-temperature gas is injected into the flame tube 2 at high speed through the gas generator nozzle 4.

[0047] The flame stabilizer 7 is welded to the inner wall of the flame tube 2 and is located upstream of the fourth row of air inlet holes.

[0048] The flame stabilizer 7 has a semi-cylindrical structure, and specifically, the concave surface of the semi-cylindrical structure faces the tail of the flame tube. The diameter of the flame stabilizer 7 is d4, the length is l5, and 0.1D2<l5<0.2D2.

[0049] Embodiment 2

[0050] The embodiment provides an assembly method of the porous transverse jet mixing afterburning chamber structure of the powder fuel ramjet engine. First, the powder fuel nozzle and the gas generator nozzle are fixedly installed at the head of the flame tube. Then, the flame stabilizer is welded to the upstream of the fourth row of air inlet holes of the flame tube and is arranged at intervals. After that, one end of the circumferentially uniformly distributed front support plate and the rear support plate is welded to the outer side of the wall surface of the flame tube, and the other end of the front support plate and the rear support plate is welded to the inner side of the outer cylinder of the afterburning chamber. The front edge of the front support plate is aligned with the front edge of the outer cylinder of the afterburning chamber and the wall surface of the flame tube, and the rear edge of the rear support plate is aligned with the rear edge of the flame tube. After that, the afterburning chamber nozzle is connected with the outer cylinder of the afterburning chamber through screw threads. Finally, the entire afterburning chamber is connected with the engine.

[0051] Embodiment 3

[0052] The embodiment provides a method for mixing porous transverse jets of a powder fuel ramjet engine. The method adopts the afterburning chamber structure in the embodiment 1. The powder fuel is carried by the fluidizing gas in the form of gas-solid two-phase flow into the flame tube of the afterburning chamber through the powder fuel nozzle. The high-temperature gas generated by the gas generator is injected into the flame tube of the afterburning chamber at high speed through the gas generator nozzle. The ramjet air first enters the annular flow channel formed by the outer cylinder of the afterburning chamber and the wall surface of the flame tube, and then enters the flame tube through the first row of air inlet holes, the second row of air inlet holes, the third row of air inlet holes and the fourth row of air inlet holes in sequence in the process of flowing downstream along the axial direction, mixes with the powder fuel and burns to form high-temperature gas which is injected out at high speed after being expanded and accelerated through the afterburning chamber nozzle.

[0053] The first row of air inlet holes are circumferentially uniformly distributed, the required penetration depth of the primary air is short, and the primary air can penetrate into the vicinity of the center of the flame tube. Meanwhile, the porous air inlet can increase the contact area of the high-temperature gas and the ramjet air. Reasonable control of the flow of the primary air can make the high-temperature gas burn at the air-fuel ratio near the appropriate chemical equivalence ratio, and preheat the powder fuel with low temperature injected by the powder fuel nozzle.

[0054] The second and third rows of air inlet holes refer to double-lateral air inlet design. The difference between double-lateral secondary air inlet and the double-lateral air inlet is that the circumferential three times air inlet holes are rotated 180° counterclockwise compared with the secondary air inlet holes. The double-lateral air inlet enhances the depth of air inlet jet, promotes the high-temperature gas to entrain the powder fuel to form a backflow in the high-temperature area of the combustion head, and increases the residence time of the powder fuel in the afterburning chamber. The second and third rows of air inlet holes are symmetrically arranged about the center of the engine section, so that the three times air inlet forms a vortex in the opposite direction of the secondary air inlet, which can reduce the vortex intensity downstream of the afterburning chamber, and in turn avoid the powder fuel particles from being thrown to the wall area by the influence of the inertial force.

[0055] The ram air entering from the air inlet hole downstream of the flame stabilizer is just in the leeward separation area of the flame stabilizer, and the jet depth is deep, and the jet depth of the remaining fourth row of air inlet holes is shallow, so that a more uniform mixing can be formed in the entire flame tube circular cross section. The leeward side low-speed area of the jet inlet air can be used to stabilize the flame. In addition, the jet inlet air of the fourth row of air inlet holes and the flame stabilizer can break the large-scale vortex formed by the second and third rows of air inlet holes into multiple small-scale vortices.

[0056] This scheme significantly improves the uniformity of the mixing of high-temperature gas, powder fuel and ram air in the afterburning chamber, increases the contact area, significantly improves the combustion efficiency, and significantly reduces the non-uniformity and non-uniformity of the outlet gas flow parameters.

Claims

1. A structure of a powder fuel ramjet multihole cross injection mixed combustion chamber, characterized by, The application relates to a powder-gas dual-propellant ramjet engine, which comprises an afterburner outer cylinder (1), a flame cylinder (2), a powder fuel nozzle (3), a gas generator nozzle (4), a front support plate (5), a rear support plate (6), a flame stabilizer (7) and an afterburner nozzle (8). The afterburner outer cylinder (1) is sleeved outside the flame cylinder (2), the annular flow channel between the afterburner outer cylinder (1) and the flame cylinder (2) is a ram air flow channel, and the afterburner outer cylinder (1) and the flame cylinder (2) are supported and connected through a plurality of front support plates (5) and rear support plates (6). The front end surface of the flame cylinder (2) is provided with the powder fuel nozzle (3) and the gas generator nozzle (4); the side wall of the flame cylinder (2) is provided with a plurality of air inlet holes so that ram air enters the combustion zone of the flame cylinder (2) in multiple times from the annular flow channel; The flame stabilizer (7) is arranged on the inner wall of the flame cylinder (2) in a circumferential interval and is located upstream of the air inlet hole in the rear part of the flame cylinder (2); The afterburner nozzle (8) is butted against the rear end of the afterburner outer cylinder (1); The diameter of the afterburner outer cylinder (1) is D1, and the length is L1; the diameter of the flame cylinder (2) is D2, and the length is L2.

2. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 1 wherein, The air inlet holes in the side wall of the flame cylinder (2) are divided into four rows, the number and diameter of the four rows of air inlet holes are different; from the front end to the rear end of the flame cylinder (2), they are a first row of air inlet holes, a second row of air inlet holes, a third row of air inlet holes and a fourth row of air inlet holes.

3. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 2 wherein, The number of the first row of air inlet holes is n1, the diameter is d1, the first row of air inlet holes is uniformly distributed in the circumferential direction, the axial distance of the first row of air inlet holes to the head of the flame cylinder (2) is l1, and 4 < n1 < 16 and 0.1D2 < l1 < 0.3D2 are met.

4. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 2 wherein, The number of the second row of air inlet holes is 2, the diameter is d2, the circumferential angle of the second row of air inlet holes is alpha, the axial distance of the second row of air inlet holes to the center of the first row of air inlet holes is l2, and 75° < alpha < 105° and 0.2D2 < l2 < 0.3D2 are met.

5. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 2 wherein, The number of the third row of air inlet holes is 2, the diameter is d3, the circumferential angle of the third row of air inlet holes is alpha, the axial distance of the third row of air inlet holes to the center of the second row of air inlet holes is l3, and 0.2D2 < l3 < 0.3D2 are met; the circumferential position of the third row of air inlet holes is obtained by rotating the circumferential position of the second row of air inlet holes counterclockwise by 180 degrees.

6. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 5 wherein, The number of the fourth row of air inlet holes is n4, the diameter is d4, the fourth row of air inlet holes is uniformly arranged in the circumferential direction, the axial distance of the fourth row of air inlet holes to the center of the third row of air inlet holes is l4, and 4 < n4 < 16 and 0.1D2 < l4 < 0.3D2 are met.

7. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 1 wherein, The front edge of the front support plate (5) is aligned with the front end of the afterburner outer cylinder (1) and the front end surface of the flame cylinder (2), and a plurality of front support plates (5) are uniformly distributed in the circumferential direction; the rear edge of the rear support plate (6) is aligned with the rear end surface of the flame cylinder (2), and a plurality of rear support plates (6) are uniformly distributed in the circumferential direction; The front support plate (5) is welded with the afterburner outer cylinder (1) and the flame cylinder (2); the rear support plate (6) is welded with the afterburner outer cylinder (1) and the flame cylinder (2).

8. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 1 wherein, The powder fuel nozzle (3) is located at the center of the front end surface of the flame tube (2); the gas generator nozzle (4) is multiple and arranged around the powder fuel nozzle (3); the powder fuel is carried by the fluidizing gas into the flame tube (2) in the form of gas-solid two-phase flow through the powder fuel nozzle (3); The high-temperature gas is injected into the flame tube (2) at high speed through the gas generator nozzle (4).

9. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber configuration of claim 2 wherein, The flame stabilizer (7) is welded to the inner wall of the flame tube (2) and located upstream of the fourth row of air inlet holes; the flame stabilizer (7) is connected with the front half side of the hole edge of the fourth row of air inlet holes.

10. The powder fuel ramjet perforated transverse jet mixed- combustion-chamber structure of claim 9, wherein The flame stabilizer (7) is a semi-cylindrical structure, the diameter of the flame stabilizer (7) is d4, the length is l5, and 0.1D2<l5<0.2D2.

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