Shock wave suction type isolation section suitable for rotary detonation engine and rotary detonation engine

Abstract

The invention discloses a shock wave suction type isolation section suitable for a rotary detonation engine and the rotary detonation engine. The rotary detonation engine comprises the shock wave suction type isolation section, an expansion section, a coaxial annular combustion chamber and a fuel injection hole formed in the rotary detonation engine. The outer diameter and the axial length of the rotary detonation engine are kept consistent with those of a coaxial circular ring rotary detonation engine before improvement, and a shock wave suction structure is arranged in the isolation section on the basis of the rotary detonation engine. A fuel belt injected by a fuel injection hole in the coaxial annular combustion chamber is ignited, rotary detonation waves which are stably propagated are generated, upstream oblique shock waves are generated, and the obtained upstream oblique shock waves are located at the position close to an inlet of the isolation section. The shock wave suction structure is additionally arranged in the isolation section to suppress upstream oblique shock waves, so that the upstream oblique shock waves are suppressed in the structure, and the purpose of reducing total pressure loss when airflow passes through is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and particularly to a shock wave suction type isolator applicable to a rotating detonation engine and a rotating detonation engine. Background Art

[0002] In the prior art, a detonation wave will generate a strong upstream oblique shock wave, which will change the flow direction of the air flow, resulting in a certain deflection of the air flow before entering the RDE combustion chamber. This deflection may affect the distribution of the air flow in the combustion chamber, thereby affecting the formation and propagation of the detonation wave. At the same time, the oblique shock wave will cause an increase in the total pressure loss of the air flow, resulting in a decrease in the total pressure of the air flow. The increase in the total pressure loss will reduce the thrust efficiency of the RDE.

[0003] Currently, there are still some studies on boundary layer suction, but there are few relevant studies on rotating detonation engines and no studies on the suction problem of the upstream oblique shock wave of rotating detonation engines. Therefore, the shock wave suction type isolator designed for rotating detonation engines in this paper is innovative and plays a guiding role in future related research. Summary of the Invention

[0004] In view of the above defects or improvement requirements of the prior art, the present invention provides a shock wave suction type isolator applicable to a rotating detonation engine and a rotating detonation engine. The purpose is to set a shock wave suction structure in the isolator, suck the upstream oblique shock wave into the structure, and through the design of the structure position and configuration, prevent the upstream oblique shock wave from propagating to the upstream of the isolator, thereby reducing the influence of the upstream oblique shock wave on the engine inlet air flow and reducing the total pressure loss caused by the upstream oblique shock wave.

[0005] On the one hand, the present invention provides a shock wave suction type isolator applicable to a rotating detonation engine, which is arranged inside the main structure of the rotating detonation engine. The isolator is an expanding structure, including a gas inlet and a shock wave suction structure. The gas inlet is located on one side of the main structure of the rotating detonation engine, and the shock wave suction structure is located in the middle of the isolator, between the gas inlet and the expanding section. One side of the expanding section is connected to the isolator, and the other side is connected to a coaxial circular combustion chamber. The other side of the coaxial circular combustion chamber includes a gas outlet. A fuel injection hole is arranged in the middle of the expanding section for injecting fuel and oxidant.

[0006] On the other hand, the present invention also provides a rotating detonation engine based on the above shock wave suction type isolator.

[0007] Generally speaking, compared with the prior art by the above technical solution conceived by the present invention, the following beneficial effects can be achieved:

[0008] (1) The shock suction type isolator applicable to a rotating detonation engine proposed by the present invention reduces the total pressure loss and the influence on the gas inlet by adding a shock suction structure in the middle section of the isolator to suck in the upstream oblique shock wave that originally reaches near the inlet of the isolator.

[0009] (2) For the shock suction type isolator applicable to a rotating detonation engine proposed by the present invention, when the shock suction structure is a cavity structure, the suppression effect on the upstream oblique shock wave is adjusted by adjusting the configuration of the cavity structure, so as to obtain a better shock suction structure.

[0010] (3) For the shock suction type isolator applicable to a rotating detonation engine proposed by the present invention, when the shock suction structure is a cavity structure, the suppression effect of the same cavity structure on upstream oblique shock waves with different intensities and the influence on the total pressure loss are obtained by adjusting the position of the designed cavity structure in the isolator, so as to obtain a better cavity setting position.

[0011] (4) For the shock suction type isolator applicable to a rotating detonation engine proposed by the present invention, when the shock suction structure is a cavity ring slot structure, the influence of the partial discharge of the flow field from the cavity outlet on the flow field and the upstream oblique shock wave is verified by setting a ring slot structure at the cavity outlet.

[0012] (5) For the shock suction type isolator applicable to a rotating detonation engine proposed by the present invention, when the shock suction structure is a cavity double-ring slot structure, a ring slot structure is set at the outlets of two cavities to achieve a stronger suppression effect on the upstream oblique shock wave, so that the upstream oblique shock wave can be sucked in and will not spread out under a smaller cavity structure.

[0013] (6) For the shock suction type isolator applicable to a rotating detonation engine proposed by the present invention, circumferentially uniformly distributed suction holes are set downstream of the coaxial ring rotating detonation engine isolator without a shock suction structure with the same outer diameter and axial length as the present invention, and compared with the shock suction structure set by the present invention to verify the rationality of the shock suction structure of the present invention. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of a coaxial ring rotating detonation engine without a shock suction structure with the same outer diameter and axial length as the rotating detonation engine used in the shock suction type isolator applicable to a rotating detonation engine designed by the present invention;

[0015] Figure 2 is a schematic structural diagram of the shock suction type isolator applicable to a rotating detonation engine designed by the present invention, and the shock suction structure is a cavity structure;

[0016] Figure 3It is a shock wave suction type isolator designed for a rotating detonation engine. The shock wave suction structure is a concave cavity structure. The concave cavity structure is located in a coaxial ring rotating detonation engine at 60% to 80% of the isolator near the upstream;

[0017] Figure 4 It is a shock wave suction type isolator designed for a rotating detonation engine. The shock wave suction structure is a concave cavity structure. It is a comparison diagram of the pressure gradient distribution of three working conditions with different positions and depths of the concave cavity structure and the working conditions of the coaxial ring rotating detonation engine before improvement with the same outer diameter and axial length.

[0018] Figure 5 It is Figure 4 By comparing the total pressure distribution diagrams of the four working conditions, the propagation mode of the upstream oblique shock wave can be obtained.

[0019] Figure 6 It is a shock wave suction type isolator designed for a rotating detonation engine. The shock wave suction structure is a concave cavity structure. It is the shock wave reflection situation in the concave cavity where the concave cavity structure is located at 40% to 60% of the isolator near the upstream.

[0020] Figure 7 It is a coaxial ring rotating detonation engine with a shock wave suction type isolator designed for a rotating detonation engine, and the shock wave suction structure is a concave cavity ring slot structure.

[0021] Figure 8 It is a coaxial ring rotating detonation engine with a shock wave suction type isolator designed for a rotating detonation engine, and the shock wave suction structure is a concave cavity double ring slot structure.

[0022] Figure 9 It is a coaxial ring rotating detonation engine with a shock wave suction type isolator designed for a rotating detonation engine, and the shock wave suction structure is a suction hole evenly distributed circumferentially.

[0023] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: the main structure of the rotating detonation engine 1; the isolator 2; the expansion section 3; the coaxial circular combustion chamber 4; the fuel injection hole 5; the shock wave suction structure 6; the gas inlet 7; the gas outlet 8. Specific embodiments

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] The object of the present invention is to suppress the upstream oblique shock by adding a shock suction structure in the isolation section, so that the upstream oblique shock is suppressed inside the structure and the total pressure loss during the airflow passing is reduced.

[0026] To achieve the above object, the present invention provides a shock suction type isolation section applicable to a rotating detonation engine. The shock suction type isolation section applicable to the rotating detonation engine is located inside the main structure of the rotating detonation engine, and a shock suction structure arranged inside the isolation section. Other structures of the rotating detonation engine include a divergent section, a coaxial circular combustion chamber, and fuel injection holes arranged inside the rotating detonation engine.

[0027] The isolation section is of a divergent structure, including a gas inlet and a shock suction structure. The gas inlet is located at the left end of the main structure of the rotating detonation engine, and the shock suction structure is located in the middle of the isolation section, between the gas inlet and the divergent section.

[0028] The left end of the divergent section is connected to the right end of the isolation section, and the right end is connected to the left end of the coaxial circular combustion chamber.

[0029] The coaxial circular combustion chamber includes a gas outlet, and the gas inlet is located at the right end of the main structure of the rotating detonation engine.

[0030] A shock suction structure is arranged inside the isolation section, which is used to suppress the intensity of the upstream oblique shock propagating upward, thereby reducing the influence of the upstream oblique shock on the engine inlet airflow, so as to achieve the reduction of the total pressure loss caused by the upstream oblique shock.

[0031] When the shock suction structure 6 is a cavity structure, the designed position of the cavity structure is between 40% and 60% of the length of the isolation section 2 close to the upstream. The depths of the inner and outer cavity structures are both 3 mm, the width is 4 mm, the cavity shape is a parallelogram at a 45-degree angle with the upstream wall surface of the isolation section, and the inner and outer cavities are symmetrical about the axial center line of the isolation section.

[0032] When the shock suction structure 6 is a cavity ring slot structure, the designed position of the cavity ring slot structure is between 40% and 60% of the length of the isolation section 2 close to the upstream. The depths of the inner and outer cavity ring slot structures are both 3 mm, the width is 4 mm, the cavity shape is a parallelogram at a 45-degree angle with the upstream wall surface of the isolation section, the inner and outer cavity ring slot structures are symmetrical about the axial center line of the isolation section, and the designed ring slot is located at the center of the upper wall surface of the inner and outer cavities, with a width of 1 mm.

[0033] When the shock wave suction structure 6 is a concave cavity double-ring slot structure, the designed position of the concave cavity double-ring slot structure is between 40% to 50% and 80% to 90% of the length of the isolator 2 near the upstream. The inner and outer concave cavity double-ring slot structures are trapezoids with a depth of 4 mm, a lower width of 3 mm, and an upper width of 2 mm. The angle between the wall surface of the trapezoidal structure near the upstream and the wall surface of the isolator is 45 degrees. The upper wall surfaces of the concave cavities are all designed ring slots. The inner and outer concave cavity double-ring slot structures are symmetric about the axial center line of the isolator.

[0034] When the shock wave suction structure 6 is a circumferentially uniformly distributed suction hole, the designed position of the suction hole is between 80% to 90% of the length of the isolator 2 near the upstream. The diameter of the suction hole is 1 mm, and the angle between adjacent suction holes relative to the engine central axis is 5 degrees, with a total of 72.

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0036] Embodiment

[0037] Please refer to Figure 1 , which is a schematic structural diagram of a coaxial circular-ring rotating detonation engine without a shock wave suction structure having the same outer diameter and axial length as the rotating detonation engine to which the shock wave suction type isolator designed by the present invention is applied. The rotating detonation engine includes a rotating detonation engine main body structure 1; an isolator 2; a diffuser 3; a coaxial circular-ring combustion chamber 4; fuel injection holes 5; a shock wave suction structure 6; a gas inlet 7; and a gas outlet 8. In the figure, the y,z coordinate system is the coordinate orientation and direction of the shock wave suction type isolator and the rotating detonation engine proposed by the present invention. The coordinates of the subsequent figures are the same.

[0038] Please refer to Figure 2 , the present invention proposes a shock wave suction type isolator and a rotating detonation engine applicable to a rotating detonation engine. The shock wave suction type isolator 2 is an expanding structure, including a gas inlet 7 and a shock wave suction structure 6. The gas inlet 7 is located at the left end of the rotating detonation engine main body structure 1, and the shock wave suction structure 6 is located in the middle of the isolator, between the gas inlet 7 and the diffuser 3;

[0039] In an embodiment of the present invention, when the shape of the shock wave suction structure 6 is a concave cavity structure, it is a parallelogram with an angle of 45 degrees with the upstream wall surface of the isolator section, the width is 4 mm, and the inner and outer concave cavity structures are symmetric about the axial center line of the isolator section and remain unchanged. By changing the position of the concave cavity structure in the isolator section 2 and the depth of the concave cavity structure, simulation analysis is carried out at the moment when the detonation wave of the rotating detonation engine stably propagates to obtain the propagation situation of the upstream oblique shock wave and the total pressure distribution in the stable state, so as to obtain a better shock wave suction structure 6 and the position of the shock wave suction structure 6 in the isolator section 2 to achieve a smaller total pressure loss, prevent the upstream oblique shock wave from reaching the isolator inlet, and reduce the influence of the upstream oblique shock wave on the inlet.

[0040] As a preferred embodiment of the present invention, when the shape of the shock wave suction structure 6 is a concave cavity ring slot structure, the designed position of the concave cavity ring slot structure is between 40% and 60% of the length of the isolator section 2 close to the upstream. The depth of the inner and outer concave cavity structures is 3 mm, the width is 4 mm, the shape of the concave cavity is a parallelogram with an angle of 45 degrees with the upstream wall surface of the isolator section, the inner and outer concave cavity ring slot structures are symmetric about the axial center line of the isolator section, and the designed ring slot is located on the upper wall surface of the concave cavity with a width of 1 mm. Verify the influence of the flow field discharged from the outlet part of the concave cavity on the flow field and the upstream oblique shock wave.

[0041] As a preferred embodiment of the present invention, when the shape of the shock wave suction structure 6 is a concave cavity double ring slot structure, the two concave cavity structures of the designed concave cavity double ring slot structure are respectively located between 40% and 50% and 80% and 90% of the length of the isolator section 2 close to the upstream, and are symmetric about the axial center line of the isolator section. The inner and outer concave cavity double ring slot structures are trapezoids with a depth of 4 mm, a lower width of 3 mm and an upper width of 2 mm. The angle between the wall surface of the trapezoid structure close to the upstream and the wall surface of the isolator section is 45 degrees, achieving a stronger inhibitory effect on the upstream oblique shock wave, and the upstream oblique shock wave can be sucked in and no longer transmitted under a smaller concave cavity structure.

[0042] As a preferred embodiment of the present invention, when the structure of the shock wave suction structure 6 is a circumferentially uniformly distributed suction hole, the designed position of the suction hole is between 80% and 90% of the length of the isolator section 2 close to the upstream, the diameter of the suction hole is 1 mm, the angle between adjacent suction holes relative to the engine central axis is 5 degrees, and there are 72 in total. Compare with the concave cavity type shock wave suction structure set in the present invention to verify the rationality of the shock wave suction structure of the present invention.

[0043] The working principle of the present invention is as follows:

[0044] By arranging a shock wave suction structure in the isolation section, the upstream oblique shock wave is sucked into the shock wave suction structure, and through the design of the configuration and position of the shock wave suction structure, the upstream oblique shock wave is no longer reflected outside the cavity, thereby reducing the influence of the upstream oblique shock wave on the engine inlet air flow and reducing the total pressure loss caused by the upstream oblique shock wave.

[0045] By reasonably adjusting the position and configuration of the shock wave suction structure arranged in the isolation section, and starting the simulation analysis at the moment when the detonation wave of the rotating detonation engine propagates stably, the propagation situation of the upstream oblique shock wave and the total pressure distribution situation in the stable state can be obtained, and a smaller total pressure loss can be obtained and the upstream oblique shock wave can be prevented from reaching the shock wave suction structure at the inlet of the isolation section.

[0046] Please refer to Figure 3 , which is a shock wave suction type isolation section applicable to a rotating detonation engine of the present invention. The shock wave suction structure is a cavity structure, and the position of the cavity structure is a coaxial ring rotating detonation engine structure between 60% and 80% of the length of the isolation section close to the upstream.

[0047] Please refer to Figure 4 , which is a pressure gradient distribution comparison diagram of the shock wave suction type isolation section applicable to a rotating detonation engine designed by the present invention. The shock wave suction structure is a cavity structure, and the cavity structure has three working conditions with different positions and depths and the working conditions of the coaxial ring rotating detonation engine before improvement with the same outer diameter and axial length. In the figure, 4-6 in 4-6-2.5 means that the cavity position is between 40% and 60% of the length of the isolation section close to the upstream, 2.5 means the cavity depth, and 4-6-3 and 6-8-3 are the same. It can be obtained that when the cavity structure is located between 40% and 60% of the length of the isolation section close to the upstream and the depth is 3mm, the axial average total pressure of the rotating detonation engine is the largest and the total pressure loss in the isolation section is the smallest.

[0048] Please refer to Figure 5 , which is a pressure gradient distribution of the shock wave suction type isolation section applicable to a rotating detonation engine designed by the present invention. The shock wave suction structure is a cavity structure, and the cavity position is in the working condition between 40% and 60% of the length of the isolation section close to the upstream and two working conditions with different positions and depths, and the above four working conditions of the coaxial ring rotating detonation engine before improvement with the same outer diameter and axial length. It can be obtained that when the cavity structure is located between 40% and 60% of the length of the isolation section close to the upstream and when the cavity structure is located between 60% and 80% of the length of the isolation section close to the upstream and the depth is 3mm, the upstream oblique shock wave of the rotating detonation engine does not reach the upstream, and the inhibitory effect of the depth increase on the upstream oblique shock wave can be obtained.

[0049] Please refer to Figure 6, the shock wave suction type isolator designed for the rotating detonation engine of the present invention, the shock wave suction structure is a concave cavity structure, and the position of the concave cavity is located in the concave cavity of the rotating detonation engine from 40% to 60% close to the upstream of the isolator. From the reflection situation of the upstream oblique shock wave in the designed concave cavity structure, it can be obtained that the upstream oblique shock wave no longer exits after being reflected in the designed concave cavity structure.

[0050] Please refer to Figure 7 , the shock wave suction type isolator of the present invention applicable to the rotating detonation engine, the shock wave suction structure 6 is a concave cavity single ring slot structure, and verify the influence of the flow field discharged from the outlet part of the concave cavity on the flow field and the upstream oblique shock wave. The result can achieve a stronger inhibitory effect on the upstream oblique shock wave, and the upstream oblique shock wave can also be sucked in and no longer exit under a smaller concave cavity structure.

[0051] Please refer to Figure 8 , the shock wave suction type isolator of the present invention applicable to the rotating detonation engine, the shock wave suction structure 6 is a concave cavity double ring slot structure, and the upper wall surfaces of the two concave cavities are both ring slots of the rotating detonation engine. By setting the ring slot structure on the upper wall surfaces of the two concave cavities, a stronger inhibitory effect on the upstream oblique shock wave is achieved.

[0052] Please refer to Figure 9 , the shock wave suction type isolator of the present invention applicable to the rotating detonation engine, the shock wave suction structure 6 is a circumferentially uniformly distributed suction hole, compare the shock wave suction structure set by the present invention, and verify the rationality of the shock wave suction structure of the present invention.

[0053] Furthermore, it is illustrated that the shock wave suction type isolator designed for the rotating detonation engine of the present invention, the shock wave suction structure 6 is a concave cavity structure, and the position of the concave cavity is located from 40% to 60% close to the upstream of the isolator, to verify the rationality of the shock wave suction type isolator.

[0054] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention, including modifications to the position, depth, size, and shape of the concave cavity, shall be included within the protection scope of the present invention.

Claims

1. A shock wave suction type isolation section suitable for a rotating detonation engine, arranged inside a main structure (1) of the rotating detonation engine, characterized in that: The isolation section is an expansion type structure, comprising a gas inlet (7) and a shock wave suction structure (6), wherein the gas inlet (7) is located on one side of the main structure (1) of the rotating detonation engine, and the shock wave suction structure (6) is located in the middle of the isolation section (2), between the gas inlet (7) and the expansion section (3); one side of the expansion section (3) is connected to the isolation section (2), and the other side is connected to the coaxial annular combustion chamber (4); the other side of the coaxial annular combustion chamber (4) comprises a gas outlet (8), and a fuel injection hole (5) is arranged in the middle of the expansion section (3), and the injection hole is a circular hole structure for injecting fuel and oxidant.

2. The shock wave suction isolation section suitable for a rotating detonation engine according to claim 1, characterized in that: When the shock wave suction structure (6) is a concave cavity structure, the position of the concave cavity structure is located between 40% and 60% of the length of the isolation section (2) close to the upstream, the depth of the inner and outer concave cavity structures is 3 mm, the width is 4 mm, and the shape of the concave cavity is a parallelogram that is at a 45-degree angle to the upstream wall of the isolation section.

3. The shock wave suction isolation section suitable for a rotating detonation engine according to claim 1, characterized in that: The shock wave suction structure (6) is a concave cavity annular gap structure, the concave cavity structure is located between 40% and 60% of the length of the isolation section (2) close to the upstream, the inner and outer concave cavity annular gap structures are both 3mm deep and 4mm wide, the concave cavity shape is a parallelogram at a 45-degree angle to the upstream wall of the isolation section, the annular gap is located on the upper wall of the concave cavity, and the width is 1mm.

4. The shock wave suction isolation section suitable for a rotating detonation engine according to claim 1, characterized in that: When the shock wave suction structure (6) is a concave cavity double annular gap structure, the designed concave cavity structure position is located between 40% to 50% and 80% to 90% of the length of the isolation section (2) close to the upstream, and the inner and outer concave cavity double annular gap structures are both trapezoidal structures with a depth of 4mm, a lower width of 3mm and an upper width of 2mm. The wall surface of the trapezoidal structure close to the upstream is at an angle of 45 degrees with the wall surface of the isolation section, and the entire upper wall surface of the concave cavity is the designed annular gap.

5. The shock wave suction isolation section suitable for a rotating detonation engine according to claim 1, characterized in that: The shock wave suction structure (6) is a suction hole evenly distributed in the circumferential direction. The suction holes are located between 80 percent and 90 percent of the length of the isolation section (2) close to the upstream, and the diameter of the suction holes is 1 mm.

6. The shock wave suction isolation section suitable for a rotating detonation engine according to claim 5, characterized in that: The angle between adjacent suction holes relative to the center axis of the engine is 5 degrees, and there are 72 in total.

7. A rotating detonation engine, characterized in that: It comprises the isolation segment as claimed in claims 1 to 6.

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