Rotary detonation combustion chamber

Abstract

The invention belongs to the technical field of engines, and discloses a rotary detonation combustion chamber which comprises a combustion chamber body, the combustion chamber body comprises a combustion chamber shell composed of an inner sleeve structure and an outer sleeve structure, a fluid channel is formed in the combustion chamber shell, and the inlet end of the fluid channel is a combustion chamber air inlet; the fluid channel comprises a combustion chamber throat section, a first expansion section, a U-shaped groove section, a second expansion section and a combustion chamber downstream straight section which are sequentially arranged. One end of the combustion chamber throat section communicates with the combustion chamber air inlet. And the U-shaped groove section comprises a U-shaped groove fillet section and a U-shaped groove straightway section which are arranged in sequence. The whole U-shaped groove fillet section is of a topological fluid diode structure, and one end, close to the first expansion section, of the topological fluid diode structure is of an arc-shaped structure. The topological fluid diode structure provides a new view angle and a new solution for optimization of the combustion chamber, and design and development of the more efficient and more stable combustion chamber are promoted.

Description

Technical Field

[0001] The invention relates to the technical field of engines, in particular to a rotating detonation combustion chamber. Background Art

[0002] The detonation combustion mechanism is that the leading shock wave compresses the reactants to self-ignite, and then the expansion of the combustion products pushes the shock wave forward. As a typical form of detonation combustion, the rotating detonation combustion chamber usually adopts an annular design. After the fuel and oxidant are mixed, they are ignited in the combustion chamber through high energy to form a detonation wave that propagates in the circumferential direction, which promotes the accelerated discharge of the gas. In theory, it can achieve higher thermal cycle efficiency and faster heat release than isobaric combustion.

[0003] like Figure 5 As shown in the figure, it presents a simplified schematic diagram of a rotating detonation combustion chamber and the intake section. This structure includes a combustion chamber body fixed to the intake end, which is further subdivided into coaxially nested inner and outer walls, forming a key intake passage between the two, allowing fuel and air to enter the combustion chamber body smoothly. The intake passage is composed of a straight channel and an expansion channel in series. The straight channel is the inlet section, which is directly connected to the external environment and allows the gas to flow in unimpeded; then, the gas enters the expansion channel. This design simulates the convergent-divergent intake scheme, aiming to improve the intake efficiency.

[0004] Regarding the above-mentioned related technologies, when the detonation engine is working normally, the combustion chamber will generate high-frequency detonation waves, and the pressure and combustion products will be transmitted back to the upstream of the combustion chamber due to the pressure difference, which will cause the engine to be unable to work stably in severe cases. The reverse transmission of the rotating detonation combustion pressure must be suppressed to prevent the pressure from being transmitted forward and causing the fan and compressor to fail to work normally. Summary of the invention

[0005] The purpose of the present invention is to provide a rotating detonation combustion chamber to solve the problem mentioned in the above background technology that when the detonation engine is working normally, the combustion chamber will generate high-frequency detonation waves, and the pressure and combustion products will be affected by the pressure difference and transmitted back to the upstream of the combustion chamber, which will cause the engine to be unable to work stably in severe cases.

[0006] To achieve the above object, the present invention provides the following technical solutions: A rotary detonation combustion chamber, comprising a combustion chamber body, the combustion chamber body comprising a combustion chamber shell composed of an inner and outer sleeve structure, a fluid channel arranged in the combustion chamber shell, the inlet end of the fluid channel being a combustion chamber air inlet, the fluid channel comprising a combustion chamber throat section, a first expansion section, a U-shaped groove section, a second expansion section and a combustion chamber downstream straight section arranged in sequence, one end of the combustion chamber throat section being in communication with the combustion chamber air inlet; The U-shaped groove section includes a U-shaped groove rounded corner section and a U-shaped groove straight section arranged in sequence, one end of the U-shaped groove rounded corner section is connected to the first expansion section, the other end of the U-shaped groove rounded corner section is provided with a U-shaped groove straight section, and the other end of the U-shaped groove straight section is connected to the second expansion section.

[0007] Further preferably, the U-shaped groove rounded corner section as a whole presents a topological fluid diode structure, and one end of the U-shaped groove rounded corner section close to the first expansion section presents an arc-shaped structure.

[0008] Further preferably, the first expansion section and the second expansion section are both trumpet-shaped structures, and the inclination angles of the first expansion section and the second expansion section are both 10°-40°.

[0009] Further preferably, the end of the second expansion section with a smaller diameter is connected to a U-shaped groove straight section, and the end of the second expansion section with a larger diameter is connected to a combustion chamber downstream straight section.

[0010] Further preferably, the single-side cross-section of the U-shaped groove segment is a U-shaped structure, the closed end center of the U-shaped groove segment of the U-shaped structure is connected to the combustion chamber throat section through the first expansion section, and the open end of the U-shaped groove segment of the U-shaped structure is provided with a U-shaped groove rounded corner section, a U-shaped groove straight section, a second expansion section and a combustion chamber downstream straight section in sequence along the intake direction.

[0011] Further preferably, the combustion chamber air inlet is annular in structure as a whole.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The U-shaped groove rounded corner section is a topological fluid diode structure as a whole. The end of the topological fluid diode structure close to the first expansion section is an arc-shaped structure, and the other end of the topological fluid diode structure is connected to a U-shaped groove straight section. Based on the characteristic advantages of the topological fluid diode structure, it can reduce the flow resistance in one direction and significantly increase the flow resistance in the opposite direction. This characteristic realizes precise control of the return of the detonation wave in the combustion chamber body. When the detonation wave propagates in the desired direction, it encounters less resistance and maintains a high propagation speed, ensuring efficient energy transfer and a stable combustion process; when the detonation wave attempts to return, it encounters strong resistance and is effectively suppressed. This mechanism greatly reduces the pressure fluctuations and heat loads in the combustion chamber body, providing a strong guarantee for the stable operation of the engine. At the same time, the topological fluid diode structure can optimize the fluid flow in the combustion chamber body, so that the fuel and oxidant are mixed more quickly and evenly, and the combustion efficiency is improved. In addition, it can also reduce the Reynolds number and reduce the resistance in the forward direction, further promoting the stable propagation of the detonation wave. In the reverse direction, the topological fluid diode structure can create a strong turbulent environment to prevent the back-transmission of pressure and combustion products, thereby protecting the upstream components in the combustion chamber body from high-pressure impact and improving the overall performance of the engine.

[0013] In summary, the structural design of the combustion chamber is directly related to the propagation efficiency of the detonation wave and the engine performance. The topological fluid diode structure provides a new perspective and solution for the structural optimization of the combustion chamber, and promotes the design and development of a more efficient and stable combustion chamber structure. Its application potential is not limited to the field of detonation engines. Its unique fluid control function makes it have broad application prospects in many fields such as aerospace, chemical industry, etc., providing new impetus for the innovation and development of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a front cross-sectional view of the overall structure of the present invention; Figure 3 It is a schematic diagram of the enlarged structure of the fluid channel of the present invention; Figure 4 It is a three-dimensional cross-sectional view of the overall structure of the present invention; Figure 5 It is a cross-sectional view of the overall structure of a traditional combustion chamber; In the figure: 3, combustion chamber body; 31, combustion chamber air inlet; 32, combustion chamber shell; 331, fluid reverse flow direction; 332, fluid forward flow direction; 34, fluid channel; 341, combustion chamber throat section; 342, first expansion section; 343, U-shaped groove rounded section; 344, U-shaped groove straight section; 345, second expansion section; 346, combustion chamber downstream straight section. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] See also Figure 1-4 , the present invention provides a technical solution: A rotary detonation combustion chamber comprises a combustion chamber body 3, the combustion chamber body 3 comprises a combustion chamber shell 32 composed of an inner sleeve structure and an outer sleeve structure, a fluid channel 34 is arranged in the combustion chamber shell 32, and an inlet end of the fluid channel 34 is a combustion chamber air intake inlet 31; The fluid channel 34 includes a combustion chamber throat section 341, a first expansion section 342, a U-shaped groove section, a second expansion section 345 and a combustion chamber downstream straight section 346 arranged in sequence, and one end of the combustion chamber throat section 341 is connected to the combustion chamber air inlet 31; The U-shaped groove section includes a U-shaped groove rounded section 343 and a U-shaped groove straight section 344 arranged in sequence, one end of the U-shaped groove rounded section 343 is connected to the first expansion section 342, the other end of the U-shaped groove rounded section 343 is provided with a U-shaped groove straight section 344, and the other end of the U-shaped groove straight section 344 is connected to the second expansion section 345.

[0017] In the present invention, the U-shaped groove rounded corner section 343 as a whole presents a topological fluid diode structure, and one end of the U-shaped groove rounded corner section 343 close to the first expansion section 342 presents an arc-shaped structure.

[0018] In the present invention, the first expansion section 342 and the second expansion section 345 are both trumpet-shaped structures, and the inclination angles of the first expansion section 342 and the second expansion section 345 are both 10°-40°.

[0019] In the present invention, the end of the second expansion section 345 with a smaller diameter is connected to the U-shaped groove straight section 344, and the end of the second expansion section 345 with a larger diameter is connected to the combustion chamber downstream straight section 346.

[0020] In the present invention, the single-side cross-section of the U-shaped groove section is a U-shaped structure, and the center of the closed end of the U-shaped groove section of the U-shaped structure is connected to the combustion chamber throat section 341 through the first expansion section 342, and the open end of the U-shaped groove section of the U-shaped structure is sequentially provided with a U-shaped groove rounded section 343, a U-shaped groove straight section 344, a second expansion section 345 and a combustion chamber downstream straight section 346 along the intake direction.

[0021] In the present invention, the combustion chamber air inlet 31 is annular in structure as a whole.

[0022] Example 1: Figure 1-4As shown, when the fluid, i.e., air and fuel, flows along the positive flow direction 332 of the fluid, the air and fuel first enter the combustion chamber body 3 through the combustion chamber air inlet 31, and then enter the U-shaped groove section through the combustion chamber throat section 341 and the first expansion section 342 in sequence. When the air and fuel flow through the combustion chamber throat section 341, since the pipe section remains unchanged, the air and fuel flow in a straight line. Then, the air and fuel pass through the first expansion section 342, and the pipe section begins to gradually increase. Due to the continuity of air and fuel, the flow rate will decrease accordingly when the flow rate remains unchanged. The air and fuel initially flow in the direction of the combustion chamber shell 32 parallel to the first expansion section 342. Due to the continuity of air and fuel (i.e., mass conservation), the flow rate will decrease accordingly when the flow rate remains unchanged. Subsequently, unstable phenomena such as eddy currents and backflows appear, and the air flows through the U-groove straight section 344 and the second expansion section 345 of the topological fluid diode structure and the downstream straight section 346 of the combustion chamber, which is equivalent to the air and fuel entering the expansion section with a larger expansion angle. The above phenomenon may be more obvious, and the eddy current phenomenon intensifies. The first expansion section 342 and the second expansion section 345 help to reduce airflow resistance, increase airflow velocity, and increase turbulence, thereby improving combustion efficiency.

[0023] When the air and fuel flow along the reverse flow direction 331 of the fluid, the air and fuel flow toward the U-groove straight section 344 and the U-groove rounded section 343 upstream of the combustion chamber body 3. At the U-groove straight section 344, the air and fuel mainly flow along a straight line. When the air and fuel reach the U-groove rounded section 343, a certain guiding effect is exerted on the air and fuel, and the flow direction thereof will gradually change to adapt to the curvature of the boundary, and a vortex phenomenon will be generated near the arc of the U-groove rounded section 343. In the semi-circular arc area of ​​the U-groove rounded section 343, the boundary layer will also be affected by the curvature and change, thereby affecting the overall flow direction of the air and fuel, thereby suppressing the return of air and fuel.

[0024] When the pressure shock wave formed in the combustion chamber body 3 is transmitted back, the returned shock wave goes straight in the U-shaped groove straight section 344, and when it enters the U-shaped groove rounded section 343, since the air and fuel are not continuous in the reverse flow process but advance in steps, and because the forward conduction ability of the topological fluid diode structure is strong, the reverse pressure pulsation is difficult to increase to the extent of breaking through the concave corner, the returned air and fuel present a vortex shape and their relative speed has a significant weakening trend in the topological fluid diode structure area, which plays a role in suppressing the return.

[0025] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0026] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A rotary detonation combustion chamber, comprising a combustion chamber body (3), the combustion chamber body (3) comprising a combustion chamber shell (32) composed of an inner and outer sleeve structure, a fluid channel (34) being arranged in the combustion chamber shell (32), the inlet end of the fluid channel (34) being a combustion chamber air intake inlet (31), characterized in that: The fluid channel (34) comprises a combustion chamber throat section (341), a first expansion section (342), a U-shaped groove section, a second expansion section (345) and a combustion chamber downstream straight section (346) which are arranged in sequence, and one end of the combustion chamber throat section (341) is in communication with the combustion chamber air inlet (31); The U-shaped groove section comprises a U-shaped groove rounded corner section (343) and a U-shaped groove straight section (344) which are arranged in sequence; one end of the U-shaped groove rounded corner section (343) is connected to the first expansion section (342); the other end of the U-shaped groove rounded corner section (343) is provided with a U-shaped groove straight section (344); the other end of the U-shaped groove straight section (344) is connected to the second expansion section (345).

2. A rotating detonation combustion chamber according to claim 1, characterized in that: The U-shaped groove rounded corner section (343) as a whole presents a topological fluid diode structure, and one end of the U-shaped groove rounded corner section (343) close to the first expansion section (342) presents an arc-shaped structure.

3. A rotating detonation combustion chamber according to claim 1, characterized in that: The first expansion section (342) and the second expansion section (345) are both trumpet-shaped structures, and the inclination angles of the first expansion section (342) and the second expansion section (345) are both 10°-40°.

4. A rotating detonation combustion chamber according to claim 1, characterized in that: The end of the second expansion section (345) with a smaller diameter is connected to a U-shaped groove straight section (344), and the end of the second expansion section (345) with a larger diameter is connected to a combustion chamber downstream straight section (346).

5. The rotating detonation combustion chamber according to claim 1, characterized in that: The single-side cross-section of the U-shaped groove section is a U-shaped structure, the center of the closed end of the U-shaped groove section of the U-shaped structure is connected to the combustion chamber throat section (341) through the first expansion section (342), and the open end of the U-shaped groove section of the U-shaped structure is provided with a U-shaped groove fillet section (343), a U-shaped groove straight section (344), a second expansion section (345) and a combustion chamber downstream straight section (346) in sequence along the air intake direction.

6. A rotating detonation combustion chamber according to claim 1, characterized in that: The combustion chamber air inlet (31) is an annular structure as a whole.

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