A rotary detonation combustor

Abstract

The present 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 includes a combustion chamber housing composed of an inner and an outer sleeve structure. A fluid passage is arranged inside the combustion chamber housing. The inlet end of the fluid passage is the combustion chamber air inlet. The fluid passage includes a combustion chamber throat section, a first expansion section, a U-shaped groove section, a second expansion section and a downstream straight section of the combustion chamber arranged in sequence. One end of the combustion chamber throat section is communicated with the combustion chamber air inlet. The U-shaped groove section includes a U-shaped groove fillet section and a U-shaped groove straight section arranged in sequence. The U-shaped groove fillet section is integrally in a topological fluid diode structure, and one end of the topological fluid diode structure close to the first expansion section is in an arc structure. The topological fluid diode structure provides a new perspective and solution for the optimization of the combustion chamber, and promotes the design and development of a more efficient and stable combustion chamber.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to a rotating detonation combustion chamber. Background Technique

[0002] The detonation combustion mechanism is that the leading shock wave compresses the reactants to auto-ignite, and then the expansion of the combustion products in turn pushes the shock wave forward. As a typical form of detonation combustion, a rotating detonation combustion chamber usually adopts an annular design. After the fuel and oxidizer are mixed, a detonation wave propagating circumferentially is formed in the combustion chamber through high-energy ignition, pushing the gas to accelerate and discharge. Theoretically, it can achieve higher thermal cycle efficiency and faster heat release compared with isobaric combustion.

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

[0004] Regarding the above-mentioned related technologies, when a detonation engine is operating normally, the combustion chamber will generate high-frequency detonation waves, and the pressure and combustion products are affected by the pressure difference and return to the upstream of the combustion chamber, which will seriously cause the engine to fail to operate stably when it is severe. It is necessary to suppress the reverse transmission of the rotating detonation combustion pressure to prevent the forward transmission of pressure from causing the fan and compressor to fail to operate normally. Summary of the Invention

[0005] The purpose of the present invention is to provide a rotating detonation combustion chamber to solve the problem that when a detonation engine is operating normally, the combustion chamber will generate high-frequency detonation waves, and the pressure and combustion products are affected by the pressure difference and return to the upstream of the combustion chamber, which will seriously cause the engine to fail to operate stably as mentioned in the above background technique.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A rotating detonation combustion chamber includes a combustion chamber body. The combustion chamber body includes a combustion chamber housing composed of an inner and outer sleeve structure. A fluid passage is provided in the combustion chamber housing. The inlet end of the fluid passage is the combustion chamber intake inlet. The fluid passage includes 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 is communicated with the combustion chamber intake inlet;

[0008] 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.

[0009] Further preferably, the U-shaped groove rounded corner section is integrally in a topological fluid diode structure, and the end of the U-shaped groove rounded corner section close to the first expansion section is in an arc-shaped structure.

[0010] Further preferably, both the first expansion section and the second expansion section are in a horn-shaped structure, and the inclination angles of the first expansion section and the second expansion section are both 10°-40°.

[0011] Further preferably, the end with a smaller diameter of the second expansion section is connected to a U-shaped groove straight section, and the end with a larger diameter of the second expansion section is connected to a straight section downstream of the combustion chamber.

[0012] Further preferably, the unilateral cross-section of the U-shaped groove section is in a U-shaped structure. The center of the closed end of the U-shaped groove section in the U-shaped structure is connected to the throat section of the combustion chamber through the first expansion section. Along the intake direction at the open end of the U-shaped groove section in the U-shaped structure, there are arranged a U-shaped groove rounded corner section, a U-shaped groove straight section, a second expansion section, and a straight section downstream of the combustion chamber in sequence.

[0013] Further preferably, the intake inlet of the combustion chamber is integrally in an annular structure.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The overall round-corner section of the U-shaped groove has a topological fluid diode structure. One end of the topological fluid diode structure close to the first expansion section has an arc-shaped structure, and the other end of the topological fluid diode structure is connected to the straight section of the U-shaped groove. Based on the characteristic advantages of the topological fluid diode structure, it can reduce the flow resistance in one direction while significantly increasing the flow resistance in the opposite direction. This characteristic enables precise control of the backpropagation of detonation waves within the combustion chamber body. When the detonation wave propagates along 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 propagate backward, it encounters strong resistance and is thus effectively suppressed. This mechanism greatly reduces the pressure fluctuations and thermal loads within the combustion chamber body, providing strong guarantee for the stable operation of the engine. At the same time, the topological fluid diode structure can optimize the fluid flow within the combustion chamber body, enabling the fuel and oxidizer to mix more quickly and evenly, thereby improving the combustion efficiency. Moreover, in the forward direction, it can reduce the Reynolds number and resistance, further promoting the stable propagation of the detonation wave. In the reverse direction, the topological fluid diode structure can create a strong turbulent environment, preventing the backpropagation of pressure and combustion products, thereby protecting the upstream components within the combustion chamber body from high-pressure impacts and improving the overall performance of the engine.

[0016] In summary, the structural design of the combustion chamber is directly related to the propagation efficiency of detonation waves and the performance of the engine. The topological fluid diode structure provides a new perspective and solution for the structural optimization of the combustion chamber, promoting the design and development of more efficient and stable combustion chamber structures. 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 and chemical engineering, providing new impetus for the innovative development of related industries. Brief Description of the Drawings

[0017] Figure 1 is the overall structural schematic diagram of the present invention;

[0018] Figure 2 is the front view cross-sectional view of the overall structure of the present invention;

[0019] Figure 3 is the enlarged structural schematic diagram of the fluid channel of the present invention;

[0020] Figure 4 is the three-dimensional cross-sectional view of the overall structure of the present invention;

[0021] Figure 5 is the cross-sectional view of the overall structure of a traditional combustion chamber;

[0022] In the figure: 3, combustion chamber body; 31, combustion chamber air inlet; 32, combustion chamber housing; 331, fluid reverse flow direction; 332, fluid forward flow direction; 34, fluid channel; 341, combustion chamber throat section; 342, first expansion section; 343, U-groove fillet section; 344, U-groove straight section; 345, second expansion section; 346, combustion chamber downstream straight section. Detailed implementation mode

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0024] Please refer to Figures 1-4 , the present invention provides a technical solution:

[0025] A rotary detonation combustion chamber includes a combustion chamber body 3. The combustion chamber body 3 includes a combustion chamber housing 32 composed of an inner and outer sleeve structure. A fluid channel 34 is arranged inside the combustion chamber housing 32, and the inlet end of the fluid channel 34 is the combustion chamber air inlet 31;

[0026] The fluid channel 34 includes a combustion chamber throat section 341, a first expansion section 342, a U-groove section, a second expansion section 345, and a combustion chamber downstream straight section 346 arranged in sequence. One end of the combustion chamber throat section 341 is communicated with the combustion chamber air inlet 31;

[0027] The U-groove section includes a U-groove fillet section 343 and a U-groove straight section 344 arranged in sequence. One end of the U-groove fillet section 343 is connected to the first expansion section 342. The other end of the U-groove fillet section 343 is provided with a U-groove straight section 344, and the other end of the U-groove straight section 344 is connected to the second expansion section 345.

[0028] In the present invention, the U-groove fillet section 343 is integrally in a topological fluid diode structure, and the end of the U-groove fillet section 343 close to the first expansion section 342 is in an arc-shaped structure.

[0029] In the present invention, both the first expansion section 342 and the second expansion section 345 are in a horn-shaped structure, and the inclination angles of the first expansion section 342 and the second expansion section 345 are both 10°-40°.

[0030] In the present invention, the end with a smaller diameter of the second expansion section 345 is connected to the U-groove straight section 344, and the end with a larger diameter of the second expansion section 345 is connected to the combustion chamber downstream straight section 346.

[0031] In the present invention, the unilateral cross-section of the U-shaped groove section is of 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 a first expansion section 342. Along the intake direction, 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 are sequentially arranged at the open end of the U-shaped groove section of the U-shaped structure.

[0032] In the present invention, the combustion chamber intake inlet 31 is integrally of an annular structure.

[0033] Example 1: As Figures 1-4 shown, when the fluid, i.e., air and fuel, flows along the fluid forward flow direction 332, the air and fuel first enter the combustion chamber body 3 through the combustion chamber intake inlet 31, and sequentially pass through the combustion chamber throat section 341 and the first expansion section 342 to enter the U-shaped groove section. When the air and fuel flow through the combustion chamber throat section 341, since the pipe cross-section remains unchanged, the air and fuel flow in a straight line. Subsequently, the air and fuel pass through the first expansion section 342, and the pipe cross-section begins to gradually increase. Due to the continuity of the air and fuel, at a constant flow rate, the flow velocity will decrease accordingly. The air and fuel initially flow along the direction of the combustion chamber housing 32 parallel to the first expansion section 342. Due to the continuity of the air and fuel (i.e., mass conservation), at a constant flow rate, the flow velocity will decrease accordingly. Subsequently, unstable phenomena such as eddy currents and backflows occur, and then they flow through the U-shaped groove straight section 344, the second expansion section 345, and the combustion chamber downstream straight section 346 of the topological fluid diode structure respectively, which is equivalent to the air and fuel entering an expansion section with a larger expansion angle. The above phenomena may be more obvious, the eddy current phenomenon intensifies. The first expansion section 342 and the second expansion section 345 help to reduce the air flow resistance, increase the air flow velocity, and increase the turbulence degree, thereby improving the combustion efficiency.

[0034] When the air and fuel flow along the fluid reverse flow direction 331, the air and fuel flow towards the U-shaped groove straight section 344 and the U-shaped groove fillet section 343 upstream of the combustion chamber body 3. At the U-shaped groove straight section 344, the main body of the air and fuel flows in a straight line. When the air and fuel reach the U-shaped groove fillet section 343, it has a certain guiding effect on the air and fuel, and its flow direction will gradually change to adapt to the curvature of the boundary. An eddy current phenomenon occurs near the arc of the U-shaped groove fillet section 343. In the semi-circular arc region of the U-shaped groove fillet 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, thus suppressing the backflow of the air and fuel.

[0035] When the pressure shock formed in the combustion chamber body 3 propagates back, the propagating shock travels straight in the straight section 344 of the U-shaped groove. When it enters the rounded corner section 343 of the U-shaped groove, since the air and fuel are not continuous during the reverse flow process but advance step by step, due to the strong forward conduction ability of the topological fluid diode structure, it is very difficult for the reverse pressure pulsation to increase to the extent of breaking through the concave corner. The reverse propagating air and fuel show a swirling shape and their relative velocity has an obvious decreasing trend in the topological fluid diode structure area, playing a role in suppressing the reverse propagation.

[0036] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claimed rights involved.

[0037] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and 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), and the other end of the U-shaped groove straight section (344) is connected to the second expansion section (345); 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; 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.

2. 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°.

3. 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).

4. 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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