A multi-turbulator combustion enhancement device for a hypersonic scramjet engine

Abstract

The application discloses a multi-turbulator combustion enhancement device of a hypersonic scramjet, and belongs to the technical field of scramjets. The device comprises a turbulator body placed in an isolation section, which is sequentially connected with a wedge section, an equal-straight section and a turbulator section along the airflow direction; at least one primary fuel-rich gas passage is formed in the equal-straight section; and the turbulator section is located around the outlet of the gas passage and is composed of a plurality of circumferentially spaced turbulators. The primary fuel-rich gas is cut and guided in multiple directions at the moment of being sprayed by directly arranging the turbulators around the gas outlet, a plurality of cross-flow vortex systems are generated, the instantaneous starting and circumferential full-area uniform mixing of the gas and the airflow air are realized, and the pressure loss is effectively reduced by the gap between the turbulators. The application solves the problems of mixing lag, poor uniformity and large pressure loss in the prior art, significantly improves the combustion efficiency of condensed-phase particles, and has compact structure and strong engineering adaptability.

Description

Technical Field

[0001] This invention belongs to the field of ramjet engine technology, specifically relating to a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine. Background Technology

[0002] In the field of ramjet engine technology, hypersonic scramjet engines utilize primary fuel-rich combustion gases generated by a gas generator to undergo secondary combustion with air, producing high-temperature combustion gases that generate thrust through the expansion of the nozzle. They offer advantages such as easily adjustable flow rate, no ignition or flame stability issues, minimal impact from incoming flow parameters during combustion chamber operation, long operating time, and flexible and varied afterburner mixing enhancement methods, indicating promising development prospects.

[0003] However, the primary combustion products of hypersonic scramjet engines typically contain over 40% condensed-phase particles, and the combustion efficiency of these high-energy particles directly determines the overall performance of the engine. Unlike pure gas-phase combustion, the combustion of condensed-phase particles strongly depends on their contact opportunities and contact time with a high-temperature, oxygen-rich environment. Therefore, enhancing the mixing uniformity of the primary fuel-rich gas (especially the condensed-phase particles within it) with the incoming air and extending its effective residence time in the combustion chamber has become a core technical challenge for improving engine performance.

[0004] Currently, research on hypersonic scramjet engines is still in its early stages both domestically and internationally. Conducting research on combustion enhancement technology for hypersonic scramjet engines is of great significance for improving the overall performance of these engines.

[0005] Existing turbulence structures are all located downstream or to the side of the gas passage, and the turbulence effect occurs a certain distance after the gas is ejected, resulting in a significant "mixing lag" problem, which makes it impossible to achieve efficient coupling at the initial moment of gas ejection. In addition, while pursuing the mixing effect, existing technologies often fail to take into account low flow resistance characteristics, resulting in a "mixing-pressure loss" contradiction.

[0006] In summary, existing technologies still face the following inherent defects: localized mixing, poor uniformity, mixing lag, and high pressure loss, making it difficult to meet the urgent needs of hypersonic scramjet engines for high efficiency, low drag, and uniform mixing throughout the entire range. Summary of the Invention

[0007] The technical problem to be solved: To overcome the shortcomings of existing technologies, this invention provides a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine. The turbulence blocks are arranged around the outlet of the primary fuel-rich gas channel, which can achieve full-circumferential synchronous disturbance at the moment the primary fuel-rich gas flows out. This solves the problems of existing technologies, such as only one-sided / central local disturbance, limited mixing range, and mixing lag, and significantly improves the overall mixing uniformity of the primary fuel-rich gas. At the same time, it can optimize the airflow path and reduce pressure loss while enhancing mixing, thus resolving the contradiction between mixing and resistance in existing technologies.

[0008] The technical solution of the present invention is: a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine, characterized in that it includes a turbulence device body 1 disposed in the isolation section 6 of the hypersonic scramjet engine, which divides the isolation section 6 into two air intake channels through the turbulence device body 1. The main body 1 of the turbulence device includes, in sequence along the airflow direction, a wedge section 2, a straight section 3 and a turbulence section 4 connected together; At least one primary fuel-rich gas passage 5 is provided within the straight section 3 along the airflow direction; The turbulence section 4 is located at the outlet of the primary fuel-rich gas channel 5 and includes multiple turbulence blocks arranged circumferentially around the outlet. At the initial moment when the primary fuel-rich gas is ejected from the primary fuel-rich gas channel 5, the gas jet is cut and guided in multiple directions around the circumference by the multiple turbulence blocks to generate multiple vortex systems, thereby achieving instantaneous start-up and uniform mixing of the primary fuel-rich gas and the incoming air under low pressure loss.

[0009] A further technical solution of the present invention is: the airflow area within the isolation section 6 remains constant along the airflow direction; the upper and lower surfaces of the wedge section 2 are triangles with acute front apex angles, and its left and right sides are trapezoids with a pair of parallel opposite sides. A further technical solution of the present invention is: the multiple turbulence blocks in the turbulence section 4 include turbulence blocks arranged on the upper side, lower side, left side and right side of the outlet of the primary fuel-rich gas channel 5, and the number of turbulence blocks on the upper and lower sides is the same and they are arranged symmetrically, and the number of turbulence blocks on the left and right sides is the same and they are arranged symmetrically.

[0010] A further technical solution of the present invention is that the turbulence block is either a cuboid or a frustum shape; and gaps are left between each turbulence block to allow airflow to pass through.

[0011] A further technical solution of the present invention is: the height of the turbulence block along the outlet airflow direction is 1 / 4 to 1 / 2 of the outlet width of the primary fuel-rich gas channel 5, and the length of the turbulence block perpendicular to the outlet airflow is 1 / 3 to 4 / 5 of the outlet width of the primary fuel-rich gas channel 5. A further technical solution of the present invention is that the number of primary fuel-rich gas channels 5 is two or more, and the multiple primary fuel-rich gas channels 5 are arranged at intervals in the vertical direction.

[0012] A hypersonic scramjet engine is characterized by comprising an isolation section 6 and a combustion chamber 7 connected sequentially along the airflow direction, wherein a multi-turbulence block combustion enhancement device for the hypersonic scramjet engine is provided in the isolation section 6 along the airflow direction. A further technical solution of the present invention is: the rear end face of the straight section 3 of the multi-turbulence block combustion enhancement device is flush with the inlet of the combustion chamber 7, and the outlet of the primary fuel-rich gas passage 5 is located at the inlet of the combustion chamber 7 or extends into the combustion chamber 7. A method for operating a hypersonic scramjet engine, characterized by comprising the following steps: Step 1: The incoming air enters from the air inlet of the isolation section 6 and is divided into two airflows, left and right, by the main body of the turbulence device 1, which flow through the left and right channels of the main body of the turbulence device 1 respectively. Step 2: The primary fuel-rich gas is ejected to the rear through the primary fuel-rich gas channel 5. At the initial moment of ejection, it is cut and guided by multiple turbulence blocks arranged circumferentially around its outlet, generating multiple vortex systems. Step 3: The two incoming air streams from the left and right meet the primary fuel-rich gas carrying multiple vortex systems in the combustion chamber 7. Driven by the multiple vortex systems, they achieve rapid and uniform mixing in the circumferential region to form a combustible mixture. Step 4: The combustible mixture undergoes secondary combustion in combustion chamber 7 to generate high-temperature gas, which expands through the nozzle to generate thrust.

[0013] A further technical solution of the present invention is: in step two, the gaps between the multiple turbulence blocks allow some airflow to pass through, so as to reduce pressure loss while enhancing mixing; In step three, the flow vortex system forms at least two pairs of vortex structures with opposite directions and mutual intersection between the primary fuel-rich combustion gas and the incoming air flow, so as to increase the area of ​​the reaction mixing layer and prolong the residence time of condensed particles in the combustion chamber. Beneficial effects The beneficial effects of this invention are as follows: This invention aims to overcome many inherent defects in the primary fuel-rich gas and incoming air mixing technology. Addressing the problems of existing turbulence structures only providing localized disturbance, poor mixing uniformity, mixing lag, and high pressure loss, it provides a combustion enhancement device with a rationally arranged turbulence device, high combustion efficiency, and low pressure loss. Specific effects are analyzed as follows: 1. This invention arranges turbulence blocks around the outlet of a primary fuel-rich gas channel and adopts a technical solution of circumferentially coordinated arrangement of multiple turbulence blocks. This allows the gas to be cut and guided by turbulence blocks in multiple directions at the initial moment of ejection, generating multiple cross-flow vortex systems. This achieves synergistic optimization of enhanced mixing and reduced pressure loss, and solves the problems of existing technologies that can only cause local disturbances, have limited mixing range, and have delayed mixing. This invention has achieved technical progress that is beyond the expectations of conventional technical means in this field. 2. The present invention uses independently arranged turbulence blocks at intervals, which generate strong disturbances while providing low-resistance channels for airflow, avoiding the high flow resistance problem caused by continuous inclined surfaces or interlocking structures. Under the premise of enhanced mixing, it effectively reduces pressure loss and achieves a balance between efficient mixing and low flow resistance. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a hypersonic scramjet engine according to an embodiment of the present invention; Figure 3 Temperature cloud map of a section located 50 mm downstream of the primary fuel-rich gas passage outlet of a traditional hypersonic scramjet engine; Figure 4 This is a temperature cloud map at a cross-section 50 mm downstream of the primary fuel-rich gas passage outlet of the hypersonic scramjet engine in this embodiment of the invention. Explanation of reference numerals in the attached drawings: 1. Body of the turbulence device, 2. Wedge section, 3. Straight section, 4. Turbulence section, 5. Primary fuel-rich gas passage, 6. Isolation section, 7. Combustion chamber. Detailed Implementation The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0015] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0016] To enhance mixing, various turbulence schemes have been proposed in the prior art. For example, patent application publication number CN107620653A discloses a method for generating disturbance by setting alternating inclined surfaces on both sides of the gas passage in relation to a hypersonic scramjet engine. However, this configuration can only cause unidirectional disturbance in a localized area and cannot achieve uniform mixing of the fuel-rich gas and the incoming air in the circumferential direction. This can easily lead to the formation of localized fuel-rich regions, resulting in low combustion efficiency and insufficient combustion stability. Patent application publication number CN109139297A further discloses a central support plate with an interlaced section at its tail formed by multiple wedge-shaped blocks to enhance mixing. This configuration concentrates the mixing effect in the central airflow region, offering limited enhancement to the mixing of the surrounding primary fuel-rich combustion gas and incoming air, resulting in insufficient overall mixing depth. Existing turbulence structures are mostly arranged on the channel sidewalls or central support plates, without integrated design around the primary fuel-rich combustion gas outlet. This prevents the primary fuel-rich combustion gas from immediately and efficiently coupling with the incoming air, leading to mixing lag. Furthermore, both alternating inclined surfaces and interlaced wedge blocks significantly increase flow resistance, resulting in higher pressure loss. While improving the mixing effect, this sacrifices overall engine efficiency, failing to achieve the technical objective of low-resistance, high-efficiency mixing.

[0017] Based on the above problems, the present invention proposes a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine, including a turbulence device body 1 disposed in the isolation section 6 of the hypersonic scramjet engine, which divides the isolation section 6 into two air intake channels through the turbulence device body 1. The main body 1 of the turbulence device includes, in sequence along the airflow direction, a wedge section 2, a straight section 3 and a turbulence section 4 connected together; At least one primary fuel-rich gas passage 5 is provided within the straight section 3 along the airflow direction; The turbulence section 4 is located at the outlet of the primary fuel-rich gas channel 5 and includes multiple turbulence blocks arranged circumferentially around the outlet. At the initial moment when the primary fuel-rich gas is ejected from the primary fuel-rich gas channel 5, the gas jet is cut and guided in multiple directions around the circumference by the multiple turbulence blocks to generate multiple vortex systems, thereby achieving instantaneous start-up and uniform mixing of the primary fuel-rich gas and the incoming air under low pressure loss.

[0018] The present invention also discloses a hypersonic scramjet engine, comprising an isolation section 6 and a combustion chamber 7 connected sequentially along the airflow direction, wherein the isolation section 6 is provided with a multi-turbulence block combustion enhancement device for the hypersonic scramjet engine along the airflow direction. The above technical solution will be further analyzed below with reference to examples and accompanying figures: In one embodiment, refer to Figure 1 and Figure 2As shown, a multi-turbulence block combustion enhancement device for a hypersonic scramjet engine includes a turbulence device body 1 placed in the isolation section 6 of the hypersonic scramjet engine, dividing the isolation section 6 into left and right air intake channels; the turbulence device body 1 includes a wedge section 2, a straight section 3 and a turbulence section 4 connected sequentially from front to back; one or more primary fuel-rich gas passages 5 are opened in the straight section 3 from front to back; the turbulence section 4 is located around the outlet of the primary fuel-rich gas passage 5 and is composed of multiple turbulence blocks.

[0019] In one embodiment, the airflow area within the isolation section 6 is constant from front to back; the upper and lower surfaces of the wedge section 2 are triangles with an acute front apex angle, and its left and right sides are trapezoids with a pair of parallel opposite sides. In one embodiment, the turbulence block in the turbulence section 4 is a cuboid or a frustum. The number of turbulence blocks in the upper, lower, left, and right sides is one or two. The height of the turbulence block is 1 / 4 to 1 / 2 of the width of the outlet of the primary fuel-rich gas channel 5, and the length of the turbulence block is 1 / 3 to 4 / 5 of the width of the outlet of the primary fuel-rich gas channel 5. The number and structure of the upper and lower turbulence blocks are symmetrical, and the number and structure of the left and right turbulence blocks are symmetrical.

[0020] In one embodiment, a hypersonic scramjet engine is disclosed, with reference to... Figure 2 As shown, it includes an isolation section 6 and a combustion chamber 7 connected sequentially from front to back. The isolation section 6 is equipped with a turbulence device body 1 from front to back. In one embodiment, the rear end face of the straight section 3 of the turbulence device body 1 is flush with the inlet of the combustion chamber 7. The primary rich gas ejected from the primary rich gas channel 5 mixes and reacts with the incoming air from the left and right airflow channels in the isolation section 6 within the combustion chamber 7. The turbulence block can effectively improve the uniformity of the primary rich gas mixing throughout the entire range, while reducing pressure loss.

[0021] The operating method of the hypersonic scramjet engine includes the following steps: Step 1: The incoming air enters from the air inlet of the isolation section 6 and is divided into two airflows, left and right, by the main body of the turbulence device 1, which flow through the left and right channels of the main body of the turbulence device 1 respectively. Step 2: The primary fuel-rich gas is ejected to the rear through the primary fuel-rich gas channel 5. At the initial moment of ejection, it is cut and guided by multiple turbulence blocks arranged circumferentially around its outlet, generating multiple vortex systems. Step 3: The two incoming air streams from the left and right meet the primary fuel-rich gas carrying multiple vortex systems in the combustion chamber 7. Driven by the multiple vortex systems, they achieve rapid and uniform mixing in the circumferential region to form a combustible mixture. Step 4: The combustible mixture undergoes secondary combustion in combustion chamber 7 to generate high-temperature gas, which expands through the nozzle to generate thrust.

[0022] Specifically, in step two, the gaps between the multiple turbulence blocks allow some airflow to pass through, thereby enhancing mixing while reducing pressure loss. In step three, the flow vortex system forms at least two pairs of vortex structures with opposite directions and mutual intersection between the primary fuel-rich combustion gas and the incoming air flow, so as to increase the area of ​​the reaction mixing layer and prolong the residence time of condensed particles in the combustion chamber.

[0023] Result verification: Numerical simulations were performed on the above embodiments and the traditional scheme (without a flow-disrupting section, but with the same structure otherwise).

[0024] For a certain formulation, the simplified composition of the primary combustion products is as follows: gas phase (60%): CO (37%), H2 (13%), H2O (0.05801%), CO2 (0.007251%), solid phase (40%): C (100%).

[0025] The hypersonic scramjet engine of this invention was tested using numerical simulation, wherein... Figure 3 This is a temperature contour map of a section located 50 mm downstream of the primary fuel-rich gas outlet in a traditional hypersonic scramjet engine. Figure 4 This is a temperature cloud map at a cross-section 50 mm downstream of the primary fuel-rich gas outlet of the hypersonic scramjet engine of this invention. Compared with conventional hypersonic scramjet engines, the hypersonic scramjet engine of this invention, equipped with a multi-turbulence block combustion enhancement device, significantly improves the overall mixing uniformity of the primary fuel-rich gas.

[0026] As shown in Table 1, the secondary combustion efficiency of the primary fuel-rich gas in the combustion chamber is clearly demonstrated. It can be seen that the hypersonic scramjet engine of this invention effectively improves the secondary combustion efficiency in the combustion chamber.

[0027] Table 1. Secondary combustion efficiency of primary fuel-rich gas in the combustion chamber

[0028] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A multi-turbulence block combustion enhancement device for a hypersonic scramjet engine, characterized in that, Includes a turbulence device body (1) installed in the isolation section (6) of the hypersonic scramjet engine, which divides the isolation section (6) into two air intake channels; The main body (1) of the turbulence device includes, in sequence along the airflow direction, a wedge section (2), a straight section (3) and a turbulence section (4). At least one primary fuel-rich gas passage (5) is provided in the straight section (3) along the airflow direction; The turbulence section (4) is located at the outlet of the primary fuel-rich gas channel (5) and includes multiple turbulence blocks arranged circumferentially around the outlet. At the initial moment when the primary fuel-rich gas is ejected from the primary fuel-rich gas channel (5), the gas jet is cut and guided in multiple directions around the circumference by the multiple turbulence blocks to generate multiple vortex systems, thereby achieving instantaneous start-up and uniform mixing of the primary fuel-rich gas and the incoming air under low pressure loss.

2. The multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to claim 1, characterized in that: The airflow area within the isolation section (6) remains constant along the airflow direction; the upper and lower surfaces of the wedge section (2) are triangles with an acute front apex angle, and the left and right sides are trapezoids with a pair of parallel opposite sides.

3. The multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to claim 1, characterized in that: The multiple turbulence blocks in the turbulence section (4) include turbulence blocks arranged on the upper, lower, left and right sides of the outlet of the primary fuel-rich gas channel (5), and the number of turbulence blocks on the upper and lower sides is the same and they are arranged symmetrically, and the number of turbulence blocks on the left and right sides is the same and they are arranged symmetrically.

4. The multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to claim 1, characterized in that: The turbulence block is either a cuboid or a frustum shape; gaps are left between each turbulence block to allow airflow to pass through.

5. The multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to claim 1, characterized in that: The height of the turbulence block along the outlet airflow direction is 1 / 4 to 1 / 2 of the outlet width of the primary fuel-rich gas channel (5), and the length of the turbulence block perpendicular to the outlet airflow is 1 / 3 to 4 / 5 of the outlet width of the primary fuel-rich gas channel (5).

6. The multi-turbulence block combustion enhancement device for a hypersonic scramjet engine according to claim 1, characterized in that: The number of primary fuel-rich gas channels (5) is two or more, and the multiple primary fuel-rich gas channels (5) are arranged at intervals in the vertical direction.

7. A hypersonic scramjet engine, characterized in that, It includes an isolation section (6) and a combustion chamber (7) connected sequentially along the airflow direction. The isolation section (6) is provided with a multi-turbulence block combustion enhancement device for the hypersonic scramjet engine according to any one of claims 1-6 along the airflow direction.

8. The hypersonic scramjet engine according to claim 7, characterized in that: The rear end face of the straight section (3) of the multi-turbulence block combustion enhancement device is flush with the inlet of the combustion chamber (7), and the outlet of the primary fuel-rich gas passage (5) is located at the inlet of the combustion chamber (7) or extends into the combustion chamber (7).

9. A method for operating a hypersonic scramjet engine based on claim 7 or 8, characterized in that, Includes the following steps: Step 1: The incoming air enters from the air inlet of the isolation section (6) and is divided into two streams of airflow by the main body (1) of the turbulence device, which flow through the left and right channels of the main body (1) of the turbulence device respectively. Step 2: The primary fuel-rich gas is ejected to the rear through the primary fuel-rich gas channel (5). At the initial moment of ejection, it is cut and guided by multiple turbulence blocks arranged around its outlet, generating multiple vortex systems. Step 3: The two incoming air streams from the left and right meet the primary fuel-rich gas carrying multiple vortex systems in the combustion chamber (7). Driven by the multiple vortex systems, they achieve rapid and uniform mixing in the circumferential domain to form a combustible mixture. Step 4: The combustible mixture undergoes secondary combustion in the combustion chamber (7) to generate high-temperature gas, which expands through the nozzle to generate thrust.

10. The working method according to claim 9: In step two, the gaps between the multiple turbulence blocks allow some airflow to pass through, so as to reduce pressure loss while enhancing mixing; In step three, the flow vortex system forms at least two pairs of vortex structures with opposite directions and mutual intersection between the primary fuel-rich combustion gas and the incoming air flow, so as to increase the area of ​​the reaction mixing layer and prolong the residence time of condensed particles in the combustion chamber.

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