A device for variable oblique ramp-skew boundary layer bleed height based on oblique detonation experiment

Abstract

The present application belongs to the technical field of oblique detonation experiment, and particularly relates to a device for variable oblique wedge boundary layer discharge height based on oblique detonation experiment, which solves the problem of oblique detonation advance initiation and detonation wave transmission caused by boundary layer in the prior art structure, and is mostly based on hole active suction with complex structure. The device is special in that: the main structure comprises a main structure plate and a cantilever fixed on the right end of the outer side of the main structure plate; the main structure plate is symmetrically provided with discharge groove height positioning outer plates with multiple rows of positioning sliding grooves on the front and back ends; the adjusting structure comprises an oblique wedge and an adjusting frame; the left end of the oblique wedge is a wedge structure, and the right end is a flat plate structure; the flat plate structure is symmetrically provided with discharge groove height positioning inner plates with multiple rows of threaded through holes on the front and back ends; the adjusting frame is fixed on the upper side of the flat plate structure and sleeved on the cantilever; the different rows of positioning sliding grooves and threaded through holes are connected to adjust the distance between the plane of the oblique wedge and the lower plate surface of the main structure plate, i.e. the discharge groove height.

Description

Technical Field

[0001] This invention belongs to the field of oblique detonation test technology, and specifically relates to a device for variable oblique wedge boundary layer discharge height based on oblique detonation test. Background Technology

[0002] Detonation is a combustion organization mode with great potential in the high Mach number range. Oblique detonation is based on oblique detonation induction, which generates a shock wave that couples with the combustion wave to form an oblique detonation wave. Oblique detonation engines are propulsion devices that utilize this combustion organization mode to generate thrust. Compared to other types of air-breathing engines, they possess unique self-pressurized combustion with a fast combustion rate; near-constant-volume combustion offers higher energy utilization and thermodynamic cycle efficiency than constant-pressure combustion, resulting in higher specific impulse and further optimization of engine thrust performance; because they lack a traditional combustion chamber, requiring only oblique detonation induction combustion, they have a shorter combustion chamber, smaller structural mass, and lower thermal protection pressure, further simplifying and lightweighting the engine structure. In short, using oblique detonation as a combustion heat release method for hypersonic vehicles holds the potential to break through the current operating Mach number limit for air-breathing engines, and has unlimited development potential.

[0003] In the process of oblique detonation induced by oblique cutting, the development of the boundary layer before oblique cutting has a significant impact on the formation and stationary state of the detonation wave. (Du Peng et al.) [1] Numerical simulations of a kerosene-fueled oblique detonation engine revealed that the interaction between the shock wave and the boundary layer can accelerate the initiation process of oblique detonation. C.Li et al. [2] Numerical simulations of a hydrogen / air mixture were used to investigate the influence of the boundary layer on the oblique detonation structure. The results showed that the boundary layer can increase shock wave energy, leading to an increase in the temperature of the induced zone and causing the oblique detonation to occur earlier. (Wang Aifeng et al.) [3] Numerical simulations using hydrogen / air were conducted to investigate the effects of viscosity and boundary layer on detonation structures. Under viscous conditions, the detonation wave angle was smaller, and detonation occurred earlier. It can be seen that the boundary layer has a certain promoting effect on the formation of oblique detonation waves, causing detonation to occur earlier, but sometimes it propagates forward.

[0004] Boundary layer suction helps stabilize the detonation wave and avoids adverse factors such as propagation. (Yuan Xueqiang et al.) [4] A hypersonic vehicle combining scrambusking and detonation was invented. The wedge surface used to induce oblique detonation is equipped with active suction holes. When the suction valve is opened, it can suction backwave products, promoting detonation wave initiation and suppressing detonation wave propagation. Cai Xiaodong et al. [5] A detonation stabilization control system was invented, which adjusts the boundary layer suction position by real-time monitoring of the detonation wave, thereby achieving dynamic stabilization of the detonation wave and efficient combustion. (Teng Honghui et al.) [6]A method and device for integrated control of the combustion chamber nozzle of a slant-knock engine are provided, in which an active suction hole is set on the combustion chamber wall. All the above inventions are based on orifice-shaped active suction, requiring dynamic detection and real-time adjustment, resulting in relatively complex structures.

[0005] The following is a description of the cited documents used in the background section above:

[0006] [1] Du Peng, Xue Rui, Wang Chen, et al. Numerical simulation of the performance of oblique detonation engine based on kerosene fuel [J / OL]. Journal of Aerospace Power, 2022, 1-11. DOI:10.13224 / j.cnki.jasp.20210670.

[0007] [2]Li C, Kailasanath K, Oran E S. Effects of boundary layers on oblique-detonation structures[C]. Aerospace Sciences Meeting, 2013.

[0008] [3] Wang Aifeng, Teng Honghui, Zhao Wei, et al. Influence of boundary layer on the structure and stability of stationary oblique detonation[J]. Science Technology and Engineering, 2013, 13(23):6781-6787.

[0009] [4] Yuan Xueqiang, Liu Weidong, Liu Shijie, Lin Zhiyong, Miao Shikun, Zhang Hailong, Zhang Duo. Detonation combustion chamber, scramjet engine and hypersonic vehicle [P]. Hunan Province, China: CN113048516A, 2021-06-29.

[0010] [5] Cai Xiaodong, Liang Jianhan, Lin Zhiyong, Liu Shijie, Chen Weiqiang. Knock Stability Control System for Scramjet Engine Based on Boundary Pumping [P]. Hunan Province, China: CN109441662A, 2019-03-08.

[0011] [6] Teng Honghui, Wang Kuanliang. An integrated control method and device for combustion chamber nozzle of a detonation engine [P]. Beijing, China: CN112761817A, 2021-05-07. Summary of the Invention

[0012] The purpose of this invention is to provide a device for variable oblique detonation boundary layer discharge height based on oblique detonation experiments, in order to solve the technical problems of existing boundary layer suction structures that are mostly based on orifice-shaped active suction, which require dynamic detection and real-time adjustment, and have relatively complex structures.

[0013] The technical solution adopted in this invention is a device for variable oblique detonation boundary layer discharge height based on oblique detonation experiments, which is special in that:

[0014] Including the main structure and the adjustment structure;

[0015] The main structure includes a horizontally arranged main structural plate and a cantilever fixed to the upper right side of the main structural plate; the front and rear ends of the main structural plate are symmetrically provided with drainage groove height positioning outer plates extending from the plate surface to the side above it.

[0016] The adjustment structure includes a wedge and an adjustment frame;

[0017] The left end of the wedge is a wedge-shaped structure with a pointed left end and a wider right end, with the wedge's inclined surface located at the bottom. The right end of the wedge is a flat plate structure. The front and rear ends of the flat plate structure are symmetrically provided with drainage groove height positioning inner plates extending upwards from the plate surface. The adjustment frame is fixedly connected to the upper plate surface of the flat plate structure.

[0018] The adjustment frame is fitted onto the cantilever and can slide left and right along the cantilever; the wedge structure is located below the main structural plate, and the inclined wedge plane above it is parallel to the lower surface of the main structural plate; the distance between the inclined wedge plane and the lower surface of the main structural plate is defined as the height of the drainage channel;

[0019] Two inner height positioning plates for the two bleed channel are fitted between two outer height positioning plates for the two bleed channel; the outer height positioning plates for the two bleed channel are provided with multiple rows of symmetrical, left-right extending positioning grooves arranged in the vertical direction; the inner height positioning plates for the two bleed channel are provided with multiple rows of symmetrical, vertically arranged threaded through holes, each row having multiple holes; the positioning grooves and threaded through holes in different rows are connected by positioning screws to adjust the height of the bleed channel.

[0020] Furthermore, it also includes drain channel fixing strips;

[0021] The flat plate structure at the right end of the wedge intersects with the wedge-shaped structure at the left end of the wedge on one side below the large end of the wedge-shaped structure;

[0022] The drain channel fixing strip is L-shaped; one side of the L-shape is set along the left and right direction and is tangent to the wedge plane, sandwiched between the wedge plane and the lower surface of the main structure plate, and the upper and lower surfaces of this side are parallel, with a thickness in the up and down direction equal to the height of the drain channel; the other side of the L-shape is hooked onto the vertical plane corresponding to the large end of the wedge structure on the left end of the wedge, and is detachably connected to the wedge; the drain channel fixing strip is selected according to the required drain channel height to precisely control the drain channel height and guide the boundary layer gas.

[0023] Furthermore, it also includes positioning pads;

[0024] The positioning pad includes a positioning pad elongated plate and a positioning pad fixing plate; the positioning pad fixing plate is fixedly connected to the right end of the positioning pad elongated plate, the two plate surfaces are perpendicular and the plate surface of the positioning pad fixing plate is tangent to the right end face of the positioning pad elongated plate.

[0025] The positioning pad plate is inserted between the upper surface of the cantilever and the inner upper surface of the adjustment frame, and the left side of the positioning pad fixing plate is tangent to the right end face of the cantilever and the right end face of the adjustment frame; the length of the positioning pad plate in the left-right direction matches the length of the adjustment frame in the left-right direction, and the width of the positioning pad plate in the front-back direction matches the front-back dimension of the inner cavity of the adjustment frame; the thickness of the positioning pad plate in the vertical direction is selected according to the required height of the drainage groove, so as to fill the vertical direction between the upper surface of the cantilever and the inner upper surface of the adjustment frame without gaps, and cooperate with the drainage groove fixing strip to play a role in positioning the vertical direction between the adjustment structure and the main structure.

[0026] A threaded hole is provided on the upper surface of the adjustment frame, and a matching first screw is provided in the threaded hole. The positioning pad is tightened by the first screw to overcome the influence of the assembly gap on the height of the drainage channel. Together with the drainage channel fixing strip, it can achieve precise control of the height of the drainage channel.

[0027] A threaded hole for the cantilever is provided on the right end face of the cantilever; a threaded hole for the right end of the adjustment frame is provided on one side above the right end face of the adjustment frame; a first through hole adapted to the threaded hole for the cantilever and the threaded hole for the right end of the adjustment frame is provided on the positioning pad fixing plate; the positioning pad is connected to the cantilever and the adjustment frame respectively by a second screw to fix the position of the adjustment structure relative to the main structure in the left and right directions.

[0028] By setting the aforementioned positioning pad, the force exerted on the cantilever threaded hole along the vertical direction of the wedge can be reduced, protecting the cantilever surface from damage by the second screw; at the same time, by setting the positioning pad, the positioning of the adjustment structure in the front-back, left-right, and up-down directions can be made more stable.

[0029] Furthermore, to facilitate pulling the positioning pad out of the adjustment frame, a pull ring is provided on the right side of the positioning pad fixing plate for pulling out the positioning pad after the experiment.

[0030] Furthermore, the difference between the horizontal center lines of two adjacent rows of positioning grooves and the row spacing between the centers of the threaded through holes in two adjacent rows is equal to the gradient value of the height change of the drainage groove. This configuration connects the positioning grooves and threaded through holes of the same number from top to bottom using positioning screws, enabling adjustment of the drainage groove height. Different rows correspond to different drainage groove heights, transforming the control of the drainage groove height into the corresponding selection of different rows of positioning grooves and threaded through holes, making height control more convenient. Simultaneously, this configuration amplifies small changes in drainage groove height into large spacing between adjacent rows of positioning grooves, facilitating initial positioning operations and further fixation after assembly.

[0031] Furthermore, the positioning groove is a U-shaped groove with its opening pointing to the right and featuring a sloping surface that gradually narrows from right to left. This design allows for easy pulling out of the entire adjustment structure without completely unscrewing the positioning screws connected to the inner plate of the drainage groove height positioning when changing the height of the drainage groove. It also makes it easier for the positioning screws to slide into the positioning groove.

[0032] Furthermore, guide plates are provided on the outer sides of both the front and rear plates of the adjustment frame to guide the gas flowing out of the drain trough further to the right, preventing the gas from spreading upward and damaging the experimental pipeline equipment.

[0033] Furthermore, in order to facilitate the positioning of the adjustment structure in the left and right directions during assembly, and for the sake of structural simplicity, the main structure also includes a cantilever transition structure;

[0034] The adjustment structure also includes two adjustment frame fixing plates;

[0035] The cantilever transition structure is plate-shaped, and its plate surface is perpendicular to the axis along the left and right direction; the cantilever is fixed to the upper right side of the main structure plate through the cantilever transition structure; the cantilever is a shape formed by stretching the cantilever cross section perpendicular to the left and right direction along the axis along the left and right direction, and the cross section of the cantilever is rectangular.

[0036] The two adjusting frame fixing plates are symmetrically arranged below the front and rear ends of the adjusting frame. The adjusting frame is fixed to the upper plate surface of the flat structure by the two adjusting frame fixing plates. The adjusting frame and the two adjusting frame fixing plates form an inverted "U" shape in the cross-sectional shape perpendicular to the left and right direction, with an inner cavity extending in the left and right direction. The width of the rectangle above the horizontal step surface corresponding to the inverted "U" shape in the front and back direction is adapted to the width of the cantilever cross-section in the front and back direction. The height of the rectangle above the horizontal step surface corresponding to the inverted "U" shape in the vertical direction is adapted to the sum of the height of the cantilever cross-section in the vertical direction and the height of the positioning pad plate in the vertical direction.

[0037] The left ends of the two adjusting frame fixing plates are in contact with the right side plate of the cantilever transition structure, which is used to position the adjusting structure in the left-right direction of the main structure.

[0038] Furthermore, in order to reduce resistance and better prevent backflow, the left end of the drain channel fixing strip is pointed;

[0039] The left end of the adjusting frame fixing plate has a wedge structure.

[0040] Furthermore, the main structural plate is the upper wall of the combustion chamber; the flat plate structure at the right end of the oblique wedge is the upper wall of the nozzle;

[0041] A flange is provided at the left end of the main structural plate for connection to the mixing section of the tilt detonation engine. This design facilitates the connection.

[0042] The beneficial effects of this invention are:

[0043] (1) In the device for variable oblique detonation boundary layer discharge height based on oblique detonation experiment of the present invention, a discharge groove is formed between the oblique plane above the oblique detonation and the lower plate of the main structure plate along the flow field direction. By selecting a suitable positioning slide and threaded through hole for connection, the discharge groove height that meets the experimental requirements can be obtained. The boundary layer suction using the device of the present invention is a non-active suction, which eliminates the complex structure of active suction. At the same time, it can maximize the discharge of the boundary layer in front of the oblique detonation to the outside, avoid causing premature detonation and detonation wave propagation, and avoid affecting the detonation initiation and stationary state. Therefore, the present invention solves the technical problem that when existing boundary layer suction structures solve the problem of premature detonation and detonation wave propagation caused by the boundary layer, most of them are based on orifice active suction, which requires dynamic detection and real-time adjustment, and the structure is relatively complex.

[0044] (2) The height of the venting channel of the device of the present invention is adjustable, which can realize the venting of different boundary layer thicknesses under different working conditions, avoid premature combustion of the boundary layer and premature detonation of oblique detonation; at the same time, it can study the influence of different boundary layer venting heights on detonation waves.

[0045] (3) Preferably, the present invention provides a drain groove fixing strip between the wedge plane and the lower surface of the main structure plate, and the drain groove fixing strip is selected according to the required drain groove height. This setting allows for precise positioning of the drain groove height. When the load-bearing adjustment structure is fixed on the main structure, the deviation between the drain groove height and the expected height caused by the assembly gap, as well as the error in the parallelism between the wedge plane and the lower surface of the main structure plate, will generate a vertical force between the wedge and the main structure, and guide the boundary layer gas to drain.

[0046] (4) Preferably, the present invention increases the stability of the adjustment structure relative to the main structure in the left-right, front-back, and up-down directions by means of the cooperation of the cantilever, adjustment frame, drain groove fixing strip and positioning pad.

[0047] (5) Preferably, the difference between the horizontal center lines of two adjacent rows of positioning grooves and the row spacing between the centers of two adjacent rows of threaded through holes is equal to the gradient value of the height change of the drainage groove. This configuration allows for the connection of positioning grooves and threaded through holes of the same number from top to bottom using positioning screws, thus adjusting the height of the drainage groove. Different rows correspond to different drainage groove heights, transforming the control of the drainage groove height into the corresponding selection of different rows of positioning grooves and threaded through holes, making the control of the drainage groove height more convenient. Simultaneously, this configuration amplifies small changes in the drainage groove height into large spacing between adjacent rows of positioning grooves, facilitating initial positioning operations and further fixation after assembly. Attached Figure Description

[0048] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the present invention (the positioning pad is in an unfolded state in the figure);

[0049] Figure 2 This is the perspective of the embodiments of the present invention and Figure 1 Schematic diagrams of the three-dimensional structure from different perspectives (the positioning pad is in the unfolded state in the figure);

[0050] Figure 3 This is the perspective of the embodiments of the present invention and Figure 1 and Figure 2 3D structural schematic diagrams from different perspectives (the positioning pad is in the unfolded state in the diagram);

[0051] Figure 4 This is a front view of an embodiment of the present invention (the positioning pad is in the unfolded state in the figure);

[0052] Figure 5 This is a cross-sectional view of the embodiment of the present invention, which is cut by a plane passing through the midpoint of the front-back direction and perpendicular to the front-back direction (the positioning pad is in the mating state in the figure).

[0053] Figure 6 This is a three-dimensional structural diagram of the main structure in an embodiment of the present invention;

[0054] Figure 7 This is a front view of the main structure in an embodiment of the present invention;

[0055] Figure 8 This is a three-dimensional structural diagram of the adjustment structure in an embodiment of the present invention;

[0056] Figure 9 This is a three-dimensional structural schematic diagram of the drain channel fixing strip in an embodiment of the present invention;

[0057] Figure 10 This is a partial schematic diagram of the connection between the drain channel fixing strip and the oblique wedge in an embodiment of the present invention;

[0058] Figure 11 This is a three-dimensional structural diagram of the positioning pad in an embodiment of the present invention;

[0059] Figure 12 This is a front view of the positioning pad in an embodiment of the present invention.

[0060] The labels in the diagram are explained as follows:

[0061] 1. Main structure, 1-1. Flange, 1-2. Main structure plate, 1-3. Cantilever, 1-4. Cantilever transition structure, 1-5. Protrusion, 1-6. Cantilever threaded hole, 1-7. Outer plate for height positioning of the drainage channel, 1-8. Positioning slide, 1-9. Lower surface of the main structure plate, 2. Adjustment structure, 2-1. Sloping wedge, 2-2. Sloping wedge slope, 2-3. Sloping wedge plane, 2-4. Rib, 2-5. Adjustment frame fixing plate, 2-6. Adjustment frame, 2-7. Adjustment frame guide plate, 2-8. Threaded hole at the right end of the adjustment frame, 2-9. Inner plate for height positioning of the drainage channel, 2-10. Threaded through hole, 2-11. Positioning screw, 3. Positioning pad, 3-1. Long plate of positioning pad, 3-2. Positioning pad fixing plate, 3-3. First through hole, 3-4. Hand pull ring, 4. Drainage channel fixing strip, 4-1. Pointed head, 4-2. Fixing structure. Detailed Implementation

[0062] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0063] See Figure 1 This invention discloses a device for a variable wedge boundary layer discharge height based on a detonation experiment, comprising a main structure 1 and an adjustment structure 2. The x-axis, y-axis, and z-axis in the accompanying drawings are defined as follows: the flow direction from left to right is the positive x-axis; the direction perpendicular to the x-axis and pointing directly upwards is the positive y-axis; the positive z-axis conforms to the right-hand rule, i.e., the positive z-axis points forward.

[0064] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 as well as Figure 7The aforementioned main structure 1 includes a horizontally arranged main structure plate 1-2 and a cantilever 1-3 fixedly connected to the upper right side of the main structure plate 1-2; the cantilever 1-3 is used to support the adjustment structure 2 vertically and to position it horizontally and vertically; the aforementioned main structure plate 1-2 has symmetrically arranged drainage groove height positioning outer plates 1-7 extending from the plate surface to the upper side at both ends; see also Figure 1 , Figure 4 , Figure 5 as well as Figure 8 The aforementioned adjustment structure 2 includes a wedge 2-1 and an adjustment frame 2-6; the left end of the wedge 2-1 is a wedge-shaped structure with a pointed left end and a wider right end, with the wedge's inclined surface 2-2 located below; the right end of the wedge 2-1 is a flat plate structure; the front and rear ends of the flat plate structure are symmetrically provided with drainage groove height positioning inner plates 2-9 extending from the plate surface to the upper side; the adjustment frame 2-6 is fixedly connected to the upper plate surface of the flat plate structure; the adjustment frame 2-6 is fitted onto the cantilever 1-3 and can slide left and right along the cantilever 1-3; the wedge structure is located below the main structural plate 1-2, and the wedge plane 2-3 above it is parallel to the lower plate surface 1-9 of the main structural plate; the wedge plane 2-3 and the lower plate surface 1-9 of the main structural plate are defined as... The distance between them is the height of the bleed channel; the two inner plates 2-9 for bleed channel height positioning are fitted between the two outer plates 1-7 for bleed channel height positioning; after assembly, the inner plates 2-9 and the outer plates 1-7 for bleed channel height positioning fit together with a certain assembly tolerance allowed; the two outer plates 1-7 for bleed channel height positioning are provided with multiple rows of left-right extending positioning grooves 1-8 arranged symmetrically in the front and back along the vertical direction; the two inner plates 2-9 for bleed channel height positioning are provided with multiple rows of threaded through holes 2-10 arranged symmetrically in the front and back along the vertical direction, with each row having multiple holes; the positioning grooves 1-8 and threaded through holes 2-10 in different rows are connected by positioning screws 2-11 to adjust the height of the bleed channel.

[0065] See Figure 1 , Figure 4 , Figure 6 as well as Figure 7 In order to make it easier for the positioning screw 2-11 to slide into the positioning groove 1-8 during assembly, and to allow the entire adjustment structure 2 to be easily pulled out without completely unscrewing the positioning screw 2-11 connected to the inner plate 2-9 of the height positioning of the effluent groove during disassembly, in this embodiment, the positioning groove 1-8 is preferably a U-shaped groove. The opening of the U-shaped groove points to the right side, and the opening is inclined, gradually changing from wide to narrow from right to left.

[0066] See Figure 1 , Figure 6 , Figure 7 as well as Figure 8To facilitate the left-right positioning of the adjustment structure 2 during assembly and for structural simplicity, this embodiment preferably includes a cantilever transition structure 1-4 as well as two adjustment frame fixing plates 2-5. The cantilever transition structure 1-4 is plate-shaped, and its plate surface is perpendicular to the axis along the left-right direction. The cantilever 1-3 is fixed to the upper right side of the main structure plate 1-2 through the cantilever transition structure 1-4. The cantilever 1-3 is formed by stretching a cantilever cross section perpendicular to the left-right direction along the axis along the left-right direction, and the cantilever cross section is rectangular. Thus, the cross section of the main structure 1 perpendicular to the front-back direction is stepped, the upper surface of the main structure plate 1-2 is the first-level step plane, and the upper surface of the cantilever 1-3 is the second-level step plane. In this embodiment, a stiffener is provided between the left side surface of the cantilever transition structure 1-4 and the upper surface of the main structure plate 1-2 for reinforcement. On the upper surface of the main structural plate 1-2, at the midpoint in the front-to-back direction, corresponding to the position between the cantilever transition structure 1-4 and the flange 1-1 described below, a protrusion 1-5 is provided. This protrusion 1-5 is used to reinforce the main structural plate 1. See also Figure 1 and Figure 8 The two adjusting frame fixing plates 2-5 are symmetrically arranged below the front and rear ends of the adjusting frame 2-6. The adjusting frame 2-6 is fixed to the upper plate surface of the above-mentioned flat structure by the two adjusting frame fixing plates 2-5. The adjusting frame 2-6 and the two adjusting frame fixing plates 2-5 form an inverted "U" shaped cross-section perpendicular to the left and right direction, with an inner cavity extending in the left and right direction. The width of the rectangle above the horizontal step surface corresponding to the inverted "U" shape in the front and back direction matches the width of the cantilever cross-section in the front and back direction. The height of the rectangle above the horizontal step surface corresponding to the inverted "U" shape in the up and down direction matches the sum of the height of the cantilever cross-section in the up and down direction and the height of the positioning pad plate 3-1 in the up and down direction. See also Figure 3 The left ends of the two adjusting frame fixing plates 2-5 mentioned above contact the right side plate surface of the cantilever transition structure 1-4, and are used to position the adjusting structure 2 in the left-right direction of the main structure 1. See Figure 8 In this embodiment, a rib 2-4 is provided between the vertical plane corresponding to the large end of the wedge-shaped structure and the adjusting frame fixing plate 2-5, and the two are connected by the rib 2-4. To better reduce resistance and prevent backflow, see [reference needed]. Figure 8 In this embodiment, the left end of the aforementioned adjusting frame fixing plate 2-5 is preferably a wedge structure. To prevent gas from diffusing upwards and damaging experimental pipelines and other equipment, see [reference needed]. Figure 1 and Figure 8In this embodiment, it is preferable to provide adjustment frame guide plates 2-7 on the outer sides of the front and rear plates of the adjustment frame 2-6, so as to further guide the gas flowing out of the drain trough to the right, and prevent the gas from spreading upward and damaging the experimental pipeline and other equipment.

[0067] To precisely control the height of the overflow channel, see [reference needed]. Figure 4 The device for variable oblique detonation boundary layer discharge height based on oblique detonation experiments in this embodiment preferably further includes a discharge channel fixing strip 4. See also Figure 5 The aforementioned flat plate structure at the right end of wedge 2-1 intersects with the aforementioned wedge-shaped structure at the left end of wedge 2-1 on the side below the large end of the wedge-shaped structure; see also Figure 4 , Figure 9 as well as Figure 10 The aforementioned drain channel fixing strip 4 is L-shaped; one side of the L-shape is set along the left-right direction and is tangent to the aforementioned wedge plane 2-3, sandwiched between the wedge plane 2-3 and the lower plate surface 1-9 of the main structure plate, and the upper and lower surfaces of this side are parallel, with a thickness along the up-down direction equal to the height of the drain channel; the other side of the L-shape, namely... Figure 9 The fixing structure 4-2 is hooked onto the vertical plane corresponding to the large end of the wedge-shaped structure at the left end of the wedge 2-1, and is detachably connected to the wedge 2-1. In this embodiment, a mounting through hole is provided on the other side of the L-shape, and a threaded hole is provided on the vertical plane corresponding to the large end of the wedge-shaped structure at the left end of the wedge 2-1. The drain groove fixing strip 4 is detachably connected to the wedge 2-1 by screws. See also Figure 9 and Figure 10 To reduce resistance and better prevent backflow, the left end of the aforementioned venting groove fixing strip 4 in this embodiment is a pointed tip 4-1. In this embodiment, there are two venting groove fixing strips 4, one symmetrically positioned at the front and one at the back on the wedge 2-1. The aforementioned venting groove fixing strips 4 are selected according to the required venting groove height to precisely control the venting groove height. When the load-bearing adjustment structure 2 is fixed on the main structure 1, the assembly gap causes a deviation between the venting groove height and the expected height, and there is an error in the parallelism between the wedge plane 2-3 and the lower plate surface 1-9 of the main structure plate. This generates a vertical force between the wedge 2-1 and the main structure 1, guiding the boundary layer venting gas.

[0068] To ensure a more stable positioning of the adjustment structure 2 in the front-back, left-right, and up-down directions of the main structure 1, see [reference needed]. Figure 1 The device for variable wedge boundary layer discharge height based on oblique detonation experiments in this embodiment preferably further includes a positioning pad 3. See also Figure 1 , Figure 11 as well as Figure 12The aforementioned positioning pad 3 includes a positioning pad elongated plate 3-1 and a positioning pad fixing plate 3-2; the positioning pad fixing plate 3-2 is fixedly connected to the right end of the positioning pad elongated plate 3-1, the surfaces of the two plates are perpendicular, and the surface of the positioning pad fixing plate 3-2 is tangent to the right end face of the positioning pad elongated plate 3-1; see also Figure 1 and Figure 2 The aforementioned positioning pad plate 3-1 is inserted between the upper surface of the cantilever 1-3 and the inner upper surface of the adjusting frame 2-6, and the left side of the positioning pad fixing plate 3-2 is tangent to the right end face of the cantilever 1-3 and the right end face of the adjusting frame 2-6; the length dimension of the positioning pad plate 3-1 in the left-right direction is adapted to the length dimension of the adjusting frame 2-6 in the left-right direction, and the width dimension of the positioning pad plate 3-1 in the front-back direction is adapted to the front-back dimension of the inner cavity of the adjusting frame 2-6; the thickness dimension of the positioning pad plate 3-1 in the vertical direction is selected according to the required height of the drainage groove, so as to fill the vertical direction between the upper surface of the cantilever 1-3 and the inner upper surface of the adjusting frame 2-6 without gaps, and cooperate with the aforementioned drainage groove fixing strip 4 to play a role in positioning the vertical direction between the adjusting structure 2 and the main structure 1. A threaded hole is provided on the upper surface of the aforementioned adjusting frame 2-6. A matching first screw is installed in the threaded hole, which tightens the positioning pad plate 3-1. At this time, the adjusting structure 2 is subjected to the force of the first screw, which overcomes the influence of the assembly gap on the height of the drainage channel. Together with the aforementioned drainage channel fixing strip 4, it achieves precise control of the height of the drainage channel. In this embodiment, there are twelve threaded holes on the upper surface of the adjusting frame, six symmetrically arranged at the front and six at the back. See also Figure 1 and Figure 2 A cantilever threaded hole 1-6 is provided on the right end face of the aforementioned cantilever 1-3; in this embodiment, there are four cantilever threaded holes 1-6, two symmetrically distributed at the front and two at the back. A right end threaded hole 2-8 is provided on one side above the right end face of the aforementioned adjusting frame 2-6; in this embodiment, there are four right end threaded holes 2-8, two symmetrically distributed at the front and two at the back, and vertically symmetrical with the aforementioned cantilever threaded holes 1-6; see [link to previous embodiment]. Figure 1In this embodiment, the right section of the upper surface of the adjusting frame 2-6 protrudes upward to accommodate the right end threaded hole 2-8 of the adjusting frame. The positioning pad fixing plate 3-2 is provided with first through holes 3-3 that are compatible with the cantilever threaded hole 1-6 and the right end threaded hole 2-8 of the adjusting frame. In this embodiment, there are eight first through holes 3-3, four symmetrically distributed at the front and four at the back. The positioning pad 3 is connected to the cantilever 1-3 and the adjusting frame 2-6 respectively by second screws to fix the position of the adjusting structure 2 relative to the main structure 1 in the left-right direction. The position of the adjusting structure 2 relative to the main structure 1 in the front-back direction is self-fixed by the cantilever 1-3 and the adjusting frame 2-6. The positioning pad elongated plate 3-1 also reduces the force exerted by the wedge 2-1 on the cantilever threaded hole 1-6 in the up-down direction, protecting the cantilever surface from damage by the second screw. By setting the positioning pad 3, the positioning of the adjusting structure 2 in the front-back, left-right, and up-down directions of the main structure 1 is more stable. See also... Figure 1 To facilitate pulling the positioning pad 3 out of the adjusting frame 2-6, a pull ring 3-4 is provided on the right side of the positioning pad fixing plate 3-2, which is used to pull out the positioning pad 3 after the experiment. When changing the height of the drainage channel, the positioning pad 3 of different thickness positioning pad long plate 3-1 needs to be replaced.

[0069] To facilitate adjustment of the overflow groove height, in this embodiment, the difference between the distance between the horizontal center lines of two adjacent rows of the aforementioned positioning grooves 1-8 and the row spacing between the centers of the two adjacent rows of the aforementioned threaded through holes 2-10 is preferably equal to the overflow groove height variation gradient value. In this embodiment, the overflow groove heights are set to 5mm, 7.5mm, 10mm, and 12.5mm; the overflow groove height variation gradient value is 2.5mm. The aforementioned positioning grooves 1-8 have four rows, corresponding to four different overflow groove heights, and the distance between the horizontal center lines of two adjacent rows of positioning grooves 1-8 is 20.5mm. The aforementioned threaded through holes 2-10 are arranged in four rows and two columns, and the row spacing between the centers of two adjacent rows of threaded through holes 2-10 is 18mm. When the height of the drainage channel is 5mm, a 5mm thick drainage channel fixing strip 4 is used. At this time, the positioning screws 2-11 on the inner plate 2-9 of the drainage channel height positioning are on the first row of the threaded through holes 2-10, and the positioning screws 2-11 are also on the first row of the positioning slides 1-8 on the outer plate 1-7 of the drainage channel height positioning. The row spacing between the centers of the holes in two adjacent rows of threaded through holes 2-10 is 18mm, and the distance between the horizontal center lines of two adjacent rows of positioning slides 1-8 is 20.5mm. That is, when the threaded through holes 2-10 in the first row match the positioning slides 1-8 in the first row, the vertical spacing between the threaded through holes 2-10 in the second row and the positioning slides 1-8 in the second row is 2.5mm. Similarly, the vertical spacing between the threaded through holes 2-10 in the third row and the positioning slides 1-8 in the third row is 5mm, and the vertical spacing between the threaded through holes 2-10 in the fourth row and the positioning slides 1-8 in the fourth row is 7.5mm. Since the height of the drain groove is 5mm when the first row is matched, the corresponding drain groove height is 7.5mm when the second row is matched, 10mm when the third row is matched, and 12.5mm when the fourth row is matched. This setup allows for adjustment of the drain groove height by connecting the same number of positioning grooves 1-8 and threaded through holes 2-10 from top to bottom using positioning screws 2-11. Different rows correspond to different drain groove heights, transforming the control of the drain groove height into the selection of corresponding positioning grooves 1-8 and threaded through holes 2-10 in different rows, as well as the selection of positioning pads 3 of different thicknesses, making the control of the drain groove height more convenient. Simultaneously, this setup amplifies small changes in the drain groove height into a large gap between adjacent rows of positioning grooves 1-8, facilitating initial positioning operations and further fixation after assembly. Furthermore, depending on experimental needs, the inner positioning plate 2-9 and the outer positioning plate 1-7 of the effluent channel height positioning can be extended upwards and downwards to set more positioning grooves 1-8 and threaded through holes 2-10, or the spacing between the positioning grooves 1-8 and threaded through holes 2-10 can be adjusted to make the gradient of the effluent channel height change smaller or larger. Simultaneously, positioning pads 3 corresponding to positioning pads 3-1 of different thicknesses can be used according to the effluent channel height setting.

[0070] The macroscopic structure of the device of this invention is the induction slashing section of a slant detonation engine, with its left end used to connect to the front section of the slant detonation engine. Specifically, in this embodiment, see... Figure 1 The aforementioned main structural plate 1-2 forms the upper wall of the combustion chamber; the aforementioned flat plate structure at the right end of the oblique wedge 2-1 forms the upper wall of the nozzle; the flange 1-1 provided at the left end of the aforementioned main structural plate 1-2 is used to connect with the mixing section of the oblique detonation engine. The flange 1-1 and the main structural plate 1-2 are reinforced by stiffening plates.

[0071] Before the experiment, when assembling the device of this embodiment, the boundary layer thickness before the wedge 2-1 was estimated using numerical simulation based on the incoming Mach number, and different bleed channel heights were selected accordingly. Then, bleed channel fixing strips 4 of corresponding thickness, positioning pads 3 corresponding to positioning pad plates 3-1 of corresponding thickness, positioning slides 1-8, and threaded through holes 2-10 were selected. Next, the selected bleed channel fixing strips 4 were connected to the wedge 2-1, and then positioning screws 2-11 were screwed into the selected threaded through holes 2-10. Align nail 2-11 with the selected positioning groove 1-8, then fit the adjustment frame 2-6 of the adjustment structure 2 into the cantilever 1-3 of the main structure 1. When the right end face of the adjustment frame 2-6 is aligned with the right end face of the cantilever 1-3, insert the positioning pad 3 so that the left side of the positioning pad fixing plate 3-2 is tightly attached to the right end face of the cantilever 1-3 and the right end face of the adjustment frame 2-6 of the main structure 1. Screw the second screw into the threaded hole 1-6 of the cantilever and the threaded hole 2-8 of the right end of the adjustment frame and tighten it. Finally, tighten the positioning screw 2-11 to complete the assembly.

[0072] After this experiment, based on the experimental conditions, the height of the effluent channel was reselected. Based on the reselected effluent channel height, the corresponding thickness of the effluent channel fixing strip 4, the corresponding thickness of the positioning pad long plate 3-1, the positioning pad 3, the positioning slide 1-8, and the threaded through hole 2-10 were reselected; and so on.

[0073] The height of the venting channel of the present invention is adjustable, which can realize venting under different working conditions and different boundary layer thicknesses, avoiding premature combustion of the boundary layer and premature detonation of oblique detonation; at the same time, it can study the influence of different boundary layer venting heights on detonation waves.

Claims

1. A device for variable oblique detonation boundary layer discharge height based on oblique detonation experiments, characterized in that: It includes the main structure (1) and the adjustment structure (2); The main structure (1) includes a horizontally arranged main structure plate (1-2) and a cantilever (1-3) fixed above the right side of the main structure plate (1-2); the front and rear ends of the main structure plate (1-2) are symmetrically provided with drainage channel height positioning outer plates (1-7) extending from the plate surface to the side above it. The adjustment structure (2) includes a wedge (2-1) and an adjustment frame (2-6); The left end of the wedge (2-1) is a wedge-shaped structure with the left end being pointed and the right end being wider, and the wedge surface (2-2) is located below. The right end of the wedge (2-1) is a flat plate structure. The front and rear ends of the flat plate structure are symmetrically provided with drainage groove height positioning inner plates (2-9) extending from the plate surface to the side above it. The adjusting frame (2-6) is fixedly connected to the upper plate surface of the flat plate structure. The adjustment frame (2-6) is fitted onto the cantilever (1-3) and can slide left and right along the cantilever (1-3); the wedge structure is located below the main structural plate (1-2), and the inclined wedge plane (2-3) above it is parallel to the lower plate surface (1-9) of the main structural plate; the distance between the inclined wedge plane (2-3) and the lower plate surface (1-9) of the main structural plate is defined as the height of the drainage channel; Two inner height positioning plates (2-9) of the two bleed channel are fitted between two outer height positioning plates (1-7) of the two bleed channel; the outer height positioning plates (1-7) of the two bleed channel are provided with multiple rows of left and right extending positioning grooves (1-8) arranged symmetrically in the front and back along the vertical direction; the inner height positioning plates (2-9) of the two bleed channel are provided with multiple rows of threaded through holes (2-10) arranged symmetrically in the front and back along the vertical direction, with each row having multiple holes; the positioning grooves (1-8) and threaded through holes (2-10) of different rows are connected by positioning screws (2-11) to realize the adjustment of the height of the bleed channel.

2. The device for variable oblique detonation boundary layer discharge height based on oblique detonation experiment according to claim 1, characterized in that: It also includes the drain channel fixing strip (4); The flat plate structure at the right end of the wedge (2-1) intersects with the wedge-shaped structure at the left end of the wedge (2-1) on one side below the large end of the wedge-shaped structure; The drain groove fixing strip (4) is L-shaped; one side of the L-shape is set along the left and right direction and is tangent to the wedge plane (2-3), sandwiched between the wedge plane (2-3) and the lower plate surface (1-9) of the main structure plate, and the upper and lower surfaces of the side are parallel, and the thickness along the up and down direction is equal to the height of the drain groove; the other side of the L-shape is hooked on the vertical plane corresponding to the large end of the wedge structure on the left end of the wedge (2-1), and is detachably connected to the wedge (2-1); the drain groove fixing strip (4) is selected according to the required drain groove height, so as to accurately control the height of the drain groove and guide the boundary layer drain gas.

3. The device for variable oblique detonation boundary layer discharge height based on oblique detonation experiment according to claim 2, characterized in that: It also includes a positioning pad (3); The positioning pad (3) includes a positioning pad elongated plate (3-1) and a positioning pad fixing plate (3-2); the positioning pad fixing plate (3-2) is fixedly connected to the right end of the positioning pad elongated plate (3-1), the two plate surfaces are perpendicular and the plate surface of the positioning pad fixing plate (3-2) is tangent to the right end face of the positioning pad elongated plate (3-1); The positioning pad long plate (3-1) is inserted between the upper surface of the cantilever (1-3) and the inner upper surface of the adjustment frame (2-6), and the left side of the positioning pad fixing plate (3-2) is tangent to the right end face of the cantilever (1-3) and the right end face of the adjustment frame (2-6); the length dimension of the positioning pad long plate (3-1) in the left-right direction is adapted to the length dimension of the adjustment frame (2-6) in the left-right direction, and the width dimension of the positioning pad long plate (3-1) in the front-back direction is adapted to the front-back dimension of the inner cavity of the adjustment frame (2-6); the thickness dimension of the positioning pad long plate (3-1) in the up-down direction is selected according to the required height of the drainage groove, so as to fill the gap between the upper surface of the cantilever (1-3) and the inner upper surface of the adjustment frame (2-6) in the up-down direction without gap, and cooperate with the drainage groove fixing strip (4) to play the role of positioning the adjustment structure (2) and the main structure (1) in the up-down direction; A threaded hole is provided on the upper surface of the adjustment frame (2-6), and a matching first screw is provided in the threaded hole. The positioning pad (3-1) is tightened by the first screw to overcome the influence of the assembly gap on the height of the drainage channel. Together with the drainage channel fixing strip (4), it can achieve precise control of the height of the drainage channel. A cantilever threaded hole (1-6) is provided on the right end face of the cantilever (1-3); an adjustment frame right end threaded hole (2-8) is provided on one side above the right end face of the adjustment frame (2-6); a first through hole (3-3) is provided on the positioning pad fixing plate (3-2) to match the cantilever threaded hole (1-6) and the adjustment frame right end threaded hole (2-8). The positioning pad (3) is connected to the cantilever (1-3) and the adjustment frame (2-6) respectively by the second screw, so as to fix the adjustment structure (2) relative to the main structure (1) in the left and right direction.

4. The apparatus for variable oblique ramped boundary layer bleed height based on oblique detonation experiment of claim 3, wherein: A pull ring (3-4) is provided on the right side of the positioning pad fixing plate (3-2) for pulling out the positioning pad (3) after the experiment.

5. The apparatus for variable oblique ramped boundary layer bleed height based on oblique detonation experiment of claim 1, wherein: The difference between the horizontal center line of the positioning groove (1-8) in the two adjacent rows and the row spacing of the threaded through hole (2-10) in the two adjacent rows is equal to the gradient value of the height change of the effluent groove.

6. The apparatus for variable oblique ramped boundary layer bleed height based on oblique detonation experiment of claim 1, wherein: The positioning groove (1-8) is a U-shaped groove with the opening of the U-shaped groove pointing to the right side and the opening being inclined, gradually narrowing from right to left.

7. The apparatus of claim 1, wherein: Adjustment frame guide plates (2-7) are provided on the outer sides of the front and rear plates of the adjustment frame (2-6) to further guide the gas flowing out of the drain trough to the right, so as to prevent the gas from spreading upward and damaging the experimental pipeline equipment.

8. The device for variable oblique detonation boundary layer discharge height based on oblique detonation experiment according to claim 3, characterized in that: The main body structure (1) further includes a cantilever transition structure (1-4); The adjusting structure (2) further includes two adjusting frame fixing plates (2-5); The cantilever transition structure (1-4) is plate-shaped, and its plate surface is perpendicular to the axis in the left-right direction; the cantilever (1-3) is fixedly connected to the upper outer side of the right end of the main body structure plate (1-2) through the cantilever transition structure (1-4); the cantilever (1-3) is a shape formed by stretching the cantilever cross-section perpendicular to the left-right direction along the axis in the left-right direction, and the cantilever cross-section is rectangular; The two adjusting frame fixing plates (2-5) are symmetrically arranged below the front and rear ends of the adjusting frame (2-6). The adjusting frame (2-6) is fixedly connected to the upper plate surface of the flat plate structure through the two adjusting frame fixing plates (2-5); the adjusting frame (2-6) and the two adjusting frame fixing plates (2-5) enclose an inner cavity with a cross-section shape perpendicular to the left-right direction and in the shape of an inverted "convex" character, extending in the left-right direction; the width dimension of the rectangle above the horizontal step surface corresponding to the inverted "convex" character in the front-rear direction is adapted to the width dimension of the cantilever cross-section in the front-rear direction; the height dimension of the rectangle above the horizontal step surface corresponding to the inverted "convex" character in the up-down direction is adapted to the sum of the height dimension of the cantilever cross-section in the up-down direction and the height dimension of the positioning pad long plate (3-1) in the up-down direction; The left ends of the two adjusting frame fixing plates (2-5) are in contact with the right side plate surface of the cantilever transition structure (1-4) for positioning the position of the adjusting structure (2) in the left-right direction of the main body structure (1).

9. The device for variable oblique wedge boundary layer flow discharge height based on oblique detonation experiment according to claim 8, wherein: The left end of the flow discharge groove fixing strip (4) is a pointed head (4-1); The left end of the adjusting frame fixing plate (2-5) is a wedge structure.

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