Flexible support ring for ignition wire of coaxial cylindrical deflagration drive

Abstract

The present invention discloses an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device, comprising a deflagration drive section and an insulating wire, wherein the deflagration drive section has a pipe; a mounting hole is formed on the deflagration drive section, and the mounting hole includes a first sub-hole, a second sub-hole, and a third sub-hole; a first sealing stud is mounted on the first sub-hole, a first through-hole is formed on the first sealing stud, a first winding post is provided on the side of the first sealing stud away from the pipe, and the first winding post is not coaxial with the first through-hole; a second sealing stud is mounted on the second sub-hole, a second through-hole is formed on the second sealing stud, a second winding post is provided on the second sealing stud, and the second winding post is not coaxial with the second through-hole; the insulating wire passes through the first through-hole and the second through-hole in sequence, and is passed from the first sealing stud to the second sealing stud; a first sealing cap is covered on the end of the first sealing stud away from the pipe. The present invention can prevent the ignition wire from excessively sagging between two electrodes, thereby exceeding the allowable range of coaxiality.

Description

Technical Field

[0001] The present invention relates to the technical field of experimental research on high-temperature and high-speed gas dynamics, high-speed aircraft, etc., and more specifically, to a flexible support ring for an ignition wire used in a coaxial cylindrical deflagration drive device. Background Art

[0002] Shock tube / wind tunnel is a kind of experimental equipment widely used in the fields of high temperature and high speed gas dynamics, high speed aircraft, etc. The basic principle is: high pressure driving gas compresses low pressure test gas through shock wave to make it reach the required test state. Figure 1 As shown, a typical shock tube / wind tunnel includes a driving section 1', a driven section 2', a nozzle 3', and a test section 4'. Before the test, the driving section 1' and the driven section 2' are separated by a diaphragm 5'. The driving section 1' is filled with high-pressure driving gas, and the driven section 2' is filled with low-pressure test gas. During the test, the diaphragm 5' ruptures, and the high-pressure gas expands and enters the driven section 2', simultaneously generating a rapidly moving shock wave in the driven section 2'. If the test is conducted directly using the gas after the shock wave, the equipment operates in shock tube mode. If the test is conducted using the test gas accelerated by the nozzle 3', the equipment operates in shock tunnel mode.

[0003] The total temperature and total pressure range of the test gas are key indicators of equipment capability, both of which depend on the driving power of the high-pressure drive gas. Room-temperature, high-pressure gas is no longer sufficient to meet increasingly demanding testing requirements. To address this, three high-performance drive technologies have been developed domestically and internationally: piston drive, heated light gas drive, and detonation drive. Detonation drive, with its low cost, simple structure, and relative safety, is currently the mainstream technology in China.

[0004] The detonation-driven shock tube was first proposed by Bird in 1957. In 1981, Mr. Yu Hongru of the Institute of Mechanics, Chinese Academy of Sciences, built a 13.3-meter-long detonation-driven shock tube, which was put into operation in 1983. In 1994, the Institute of Mechanics, Chinese Academy of Sciences, developed the JF-10 detonation-driven high-enthalpy shock tunnel [see Yu Hongru, Zhao Wei, and Yuan Shengxue, Performance of Hydrogen-Oxygen Detonation-Driven Shock Tunnels - Aerodynamic Test and Measurement Control, 1993, 7(3): 38-42]. With the help of Mr. Yu Hongru, Gronig et al. built a high-enthalpy shock tunnel (TH2-D) using reverse detonation drive at the RWTH Aachen University in Germany in 1993. In 1994, NASA modified the original free-piston-driven design and built the forward detonation-driven high-enthalpy shock tunnel (HYPULSE) at GASL. The tunnel can operate in both reflected shock tunnel mode and expansion tube mode [see Chue RSM, Tsai CY, Bakos RJ, Erdos JI, Rogers RC (2002) NASA's HYPULSE Facility at GASL - A Dual Mode, Dual Driver Reflected-Shock / Expansion Tunnel. In: Lu F, Marren D (eds), Advanced Hypersonic Test Facilities, Progress in Astronautics and Aeronautics, Vol. 198, AIAA, Chapter 3, pp29-71].

[0005] Detonation drive requires the formation of an axially propagating detonation wave within the drive section. The uneven flow field behind the detonation wave causes the following problems with this drive technology: First, the range of gas mixture ratios that can detonate is much narrower than the range that can deflagrate, and the temperature and sound velocity ranges of the driving gas are also correspondingly narrower, thus limiting the total temperature range of the test gas that can be provided by the detonation drive; second, the effective driving pressure provided by the detonation drive does not exceed 40% of the equipment's pressure limit, limiting the total pressure range of the test gas.

[0006] To overcome the aforementioned challenges of detonation drive, coaxial cylindrical deflagration drive technology is needed. However, this requires high-voltage electrodes at each end of the drive section, with an ignition wire placed between the two electrodes along the centerline of the drive section axis. However, shock tubes and shock tunnels are pulsed experimental devices, with effective experimental times in the millisecond range. This time scales directly with the length of the shock tube or shock tunnel. To achieve longer experimental times, the tube length must be increased. For example, the JF-12 shock tunnel at the Institute of Mechanics, Chinese Academy of Sciences, is over 200 meters long. In large-scale deflagration-driven shock tubes and shock tunnels, support is required at the center of the ignition wire to prevent it from sagging excessively between the two electrodes and exceeding the allowable coaxiality. This support structure must simultaneously meet the following requirements: 1. Ensure airtightness and withstand high pressures; 2. Ensure insulation and prevent localized breakdown.

[0007] The existing document (CN102407947A) discloses a shock tunnel detonation dual-drive device, comprising: a shock tunnel, the shock tunnel having a detonation drive section, one end of the detonation drive section is provided with a detonation discharge section, and the other end is provided with a driven section; a first diaphragm is provided between the detonation discharge section and the detonation drive section, and a second diaphragm is provided between the driven section and the detonation drive section; a forward detonation drive ignition device is provided at a section of the detonation drive section close to the detonation discharge section, and a reverse detonation drive ignition device is provided at a section of the detonation drive section close to the driven section; a controllable delay trigger device is connected between the forward detonation drive ignition device and the reverse detonation drive ignition device. The method is as follows: 1) a forward detonation ignition device is provided at one end of the detonation driving section of the shock tunnel close to the detonation unloading section, and a reverse detonation driving ignition device is provided at one end of the detonation driving section close to the driven section; 2) ignition is performed by the forward detonation ignition device to form a forward-driven detonation wave; 3) after the forward detonation wave propagates along the detonation driving section for a predetermined time, ignition is performed by the reverse detonation driving ignition device to form a reverse-driven detonation wave; 4) the reverse-driven detonation wave tears a diaphragm provided between the driven section and the detonation driving section, and the forward detonation wave and the reverse detonation wave intersect to form a moving shock wave, which enters the driven section to compress the test gas in the driven section.

[0008] In order to meet the coaxiality requirements of the coaxial cylindrical deflagration drive technology for the ignition wire and the drive section tube body, the present invention proposes a flexible support ring for the ignition wire for the coaxial cylindrical deflagration drive device, and the flexible support ring for the ignition wire for the coaxial cylindrical deflagration drive device is not easily conceived by those skilled in the art. Summary of the Invention

[0009] In view of this, the present invention provides an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device, comprising a deflagration drive section and an insulating wire, wherein the deflagration drive section has a pipe;

[0010] The deflagration drive section is provided with at least three mounting holes along a circumferential direction, wherein the at least three mounting holes include a first sub-hole, a second sub-hole, and a third sub-hole, wherein the first sub-hole and the second sub-hole are arranged opposite to each other along a first direction, and the first direction is a direction from the first sub-hole to the second sub-hole;

[0011] A first sealing stud is installed on the first sub-hole, a first through hole extending along the first direction is opened on the first sealing stud, a first winding post is provided on the side of the first sealing stud away from the pipe, and the first winding post is not coaxial with the first through hole;

[0012] A second sealing stud is installed on the second sub-hole, a second through hole extending along the first direction is opened on the second sealing stud, a second winding post is provided on the side of the second sealing stud away from the pipe, and the second winding post is not coaxial with the second through hole;

[0013] The insulating wire passes through the first through hole and the second through hole in sequence from the first sealing stud to the second sealing stud, wherein one end of the insulating wire is connected to the first winding post, and the other end of the insulating wire is connected to the second winding post;

[0014] The first sealing stud is covered with a first sealing cap at one end away from the pipe, and the second sealing stud is covered with a second sealing cap at one end away from the pipe;

[0015] The third sub-hole is located between the first sub-hole and the second sub-hole.

[0016] Optionally, the diameters of the first through hole and the second through hole are 5-10 mm respectively.

[0017] Optionally, the diameters of the first winding pole and the second winding pole are 3-6 mm respectively.

[0018] Optionally, the insulating wire is made of polytetrafluoroethylene, polyamide or phenylenediamine.

[0019] Optionally, the third sub-hole is located below the deflagration driving section.

[0020] Compared with the prior art, the flexible support ring for the ignition wire of the coaxial cylindrical deflagration drive device provided by the present invention achieves at least the following beneficial effects:

[0021] In this embodiment, the flexible support ring for the ignition wire used in a coaxial cylindrical deflagration drive device comprises a first through-hole extending in a first direction on a first sealing stud and a second through-hole extending in the first direction on a second sealing stud. The insulating wire passes through the first through-hole and the second through-hole, respectively, from the first sealing stud to the second sealing stud. The ends of the insulating wire are respectively wound around the first winding post and the second winding post and then secured. This not only prevents the ignition wire from excessively sagging between the two electrodes, thereby exceeding the allowable range of coaxiality, but also avoids the generation of large debris after the experiment. If the insulating wire 500 breaks after the experiment, it can be directly removed. Even if debris is present, it can be easily blown by the airflow to a location at the end of the deflagration drive section for easy cleaning. Furthermore, the first sealing stud cooperates with the first sealing cap, and the second sealing stud cooperates with the second sealing cap, effectively ensuring airtightness within the deflagration drive section and capable of withstanding high pressure. It should be noted that the deflagration drive technology requires two electrodes to be plugged into the ends of the deflagration drive section, with the ignition wire arranged between the two electrodes along the axis of the deflagration drive section.

[0022] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Figure 1 This is a schematic diagram of the structure of a shock tube / wind tunnel provided in the prior art;

[0026] Figure 2 Schematic diagram I of the structure of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

[0027] Figure 3 1 is a cross-sectional schematic diagram of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

[0028] Figure 4 Schematic diagram II of the structure of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

[0029] Figure 5 This is a schematic structural diagram of a deflagration drive section provided by an embodiment of the present invention;

[0030] Figure 6Schematic diagram of the structure of a coaxial cylindrical deflagration drive device for a shock tube / wind tunnel provided by an embodiment of the present invention;

[0031] Figure 7 yes Figure 6 A magnified view of the structure at point B in the middle;

[0032] Figure 8 yes Figure 6 A magnified diagram of the structure of the discharge system;

[0033] Figure 9 This is a logic block diagram of a discharge system provided by an embodiment of the present invention;

[0034] Figure 10 Schematic diagram of the structure of a shock tube / wind tunnel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0036] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0037] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0038] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0039] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0040] Figure 2 Schematic diagram I of the structure of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention; Figure 3 1 is a cross-sectional schematic diagram of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention; Figure 4 Schematic diagram II of the structure of an ignition wire flexible support ring for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a deflagration drive section provided by an embodiment of the present invention; Figure 2-5As shown, this embodiment provides an ignition wire flexible support ring 1000 for a coaxial cylindrical deflagration drive device, comprising a deflagration drive section 1 and an insulating wire 500, wherein the deflagration drive section 1 has a pipe 100;

[0041] The deflagration drive section 1 is provided with at least three mounting holes 200 along the circumferential direction. The at least three mounting holes 200 include a first sub-hole 201, a second sub-hole 202, and a third sub-hole 203. The first sub-hole 201 and the second sub-hole 202 are arranged opposite to each other along a first direction E. The first direction E is the direction from the first sub-hole 201 to the second sub-hole 202.

[0042] A first sealing stud 300 is installed on the first sub-hole 201. The first sealing stud 300 is provided with a first through hole 301 extending along the first direction E. A first winding post 302 is provided on the side of the first sealing stud 300 away from the pipe 100. The first winding post 302 is located beside the first through hole 301 and the first winding post 302 is not coaxial.

[0043] A second sealing stud 400 is installed on the second sub-hole 202. A second through hole 401 extending along the first direction E is formed on the second sealing stud 400. A second winding post 402 is provided on the side of the second sealing stud 400 away from the pipe 100. The second winding post 402 is located beside the second through hole 401 and the two are not coaxial.

[0044] One end of the insulating wire 500 is fixed to the first winding post 302 , and the other end passes through the first through hole 301 and the second through hole 401 in sequence and is fixed to the second winding post 402 ;

[0045] The end of the first sealing stud 300 away from the pipe 100 is covered with a first sealing cap 303 , and the end of the second sealing stud 400 away from the pipe 100 is covered with a second sealing cap 403 ;

[0046] The third sub-hole 203 is located between the first sub-hole 201 and the second sub-hole 202 .

[0047] Specifically, the ignition wire flexible support ring 1000 for the coaxial cylindrical deflagration drive device includes a deflagration drive section 1 and an insulating wire 500. The deflagration drive section 1 has a pipe 100, and an ignition wire 13 extending in the axial direction is arranged in the pipe 100; the material of the insulating wire 500 can be polytetrafluoroethylene, polyamide or phenylenediamine. Polytetrafluoroethylene is heat-resistant and can withstand high temperatures of up to 300°C for a short time. Polyamide, commonly known as nylon, has the advantages of high mechanical strength, good toughness, high tensile and compressive strength, high softening point, and heat resistance. Phenylenediamine, commonly known as aramid, has the characteristics of ultra-high strength, high temperature resistance, insulation, and aging resistance. The insulating wire 500 uses the above materials to prevent the flexible support ring from conducting.

[0048] The deflagration drive section 1 is provided with at least three mounting holes 200 along the circumferential direction. The at least three mounting holes 200 include a first sub-hole 201, a second sub-hole 202, and a third sub-hole 203. The first sub-hole 201 and the second sub-hole 202 are arranged relative to each other along a first direction E. The first direction E is the direction from the first sub-hole 201 to the second sub-hole 202. The first direction E intersects with the axial direction. Optionally, the first direction E is perpendicular to the axial direction.

[0049] A first sealing stud 300 is installed on the first sub-hole 201. The first sealing stud 300 is used to seal the first sub-hole 201 to prevent the combustible mixture in the pipeline 100 from leaking from the first sub-hole 201. The first sealing stud 300 is provided with a first through hole 301 extending along the first direction E. The first through hole 301 passes through the first sealing stud 300 along the first direction E. The first through hole 301 is used to pass the insulating wire 500. The first sealing stud 300 is away from the side of the pipeline 100. A first winding post 302 is provided, and the first winding post 302 is used to wind one end of the insulating wire 500 and then fix it. The first winding post 302 is not coaxial with the first through hole 301. It can be understood that the first winding post 302 is located beside the first through hole 301. After one end of the insulating wire 500 passes through the first through hole 301, it can be wound on the first winding post 302 and then fixed. The provision of the first winding post 302 does not affect the one end of the insulating wire 500 passing through the first through hole 301.

[0050] A second sealing stud 400 is installed on the second sub-hole 202. The second sealing stud 400 is used to seal the second sub-hole 202 to prevent the combustible mixture in the pipeline 100 from leaking from the second sub-hole 202. The second sealing stud 400 is provided with a second through hole 401 extending along the first direction E, that is, the second through hole 401 passes through the second sealing stud 400 along the first direction E. The second through hole 401 is used to pass the insulating wire 500. A second winding post 402 is provided on the side of the second sealing stud 400 away from the pipeline 100. The second winding post 402 is used to wind the other end of the insulating wire 500 and fix it.

[0051] The second winding post 402 is not coaxial with the second through hole 401. It can be understood that the second winding post 402 is located beside the second through hole 401. After the other end of the insulating wire 500 passes through the first through hole 301, it can be wound around the second winding post 402 and then fixed. The arrangement of the second winding post 402 does not affect the other end of the insulating wire 500 passing through the second through hole 401.

[0052] The insulating wire 500 passes through the first through hole 301 and the second through hole 401 in sequence from the first sealing stud 300 to the second sealing stud 400, wherein one end of the insulating wire 500 is connected to the first winding post 302, and the other end of the insulating wire 500 is connected to the second winding post 402; if the insulating wire 500 first passes through the first through hole 301 from the first sealing stud 300, passes through the pipe 100, and then passes through the second sealing stud 400 through the second through hole 401, after the insulating wire 500 is tightened, one end of the insulating wire 500 is first wound on the first winding post 302 and then fixed, and the other end of the insulating wire 500 is wound on the second winding post The wire is wound around the wire post 402 and then fixed. Of course, when two people operate, after the insulating wire 500 is tightened, the two people wind the wire and fix it synchronously. For example, one person winds one end of the insulating wire 500 around the first winding post 302 and fixes it, and the other person winds the other end of the insulating wire 500 around the second winding post 402 and fixes it. They can do it at the same time. Alternatively, one end of the insulating wire 500 can be wound around the first winding post 302 and then fixed, and then the insulating wire 500 is passed through the first through hole 301 and the second through hole 401 in sequence from the first sealing stud 300 on one side to the second sealing stud 400 on the other side, and then the other end of the insulating wire 500 is wound around the second winding post 402 and then fixed.

[0053] The first sealing stud 300 is covered with a first sealing cap 303 at one end away from the pipe 100. The first sealing cap 303 is used to cover the first sealing stud 300. The second sealing stud 400 is covered with a second sealing cap 403 at one end away from the pipe 100. The second sealing cap 403 is used to cover the second sealing stud 400. That is, after the two ends of the insulating wire 500 are fixed to the first winding post 302 and the second winding post 402, respectively, the first sealing cap 303 is used to cover the first sealing stud 300, and the second sealing cap 403 is used to cover the second sealing stud 400.

[0054] The third sub-hole 203 is located between the first sub-hole 201 and the second sub-hole 202. The third sub-hole 203 is designed between the first sub-hole 201 and the second sub-hole 202. The third sub-hole 203 is an operating hole. The user can insert a temporary bracket into the third sub-hole 203 to lift the ignition wire arranged in the pipe 100, and then pass the insulating wire 500 through the lower end of the ignition wire, and wind the two ends of the insulating wire 500 around the first winding post 302 and the second winding post 402, and fix them. In order to facilitate user operation, the third sub-hole 203 can be set below the deflagration drive section 1.

[0055] During specific use, the ignition wire in the pipe 100 is first straightened, and then a temporary bracket is inserted into the third sub-hole 203 to lift the ignition wire; then a threading tool is used to pass the insulating wire 500 from the first sealing stud 300 on one side through the second sealing stud 400 on the other side through the first through hole 301 and the second through hole 401; finally, after the insulating wire 500 is tightened and fixed on the first winding post 302 and the second winding post 402 respectively, the first sealing cap 303 and the second sealing cap 403 are respectively covered. At this time, the ignition wire is located above the insulating wire 500. After the temporary bracket is removed, the ignition wire is placed on the tightened insulating wire 500 to form an ignition wire support structure; the ignition wire flexible support ring 1000 will not produce large pieces of debris. If the insulating wire 500 is broken after the experiment, it can be taken out directly. Even if there are small debris, it can be easily blown by the airflow to the positions at the head and tail ends of the deflagration drive section 1 that are easy to clean.

[0056] As can be seen from the above embodiments, the ignition wire flexible support ring 1000 for the coaxial cylindrical deflagration drive device provided in this embodiment achieves at least the following beneficial effects:

[0057] In this embodiment, the flexible support ring 1000 for the ignition wire of a coaxial cylindrical deflagration drive device has a first through hole 301 extending in a first direction E on the first sealing stud 300 and a second through hole 401 extending in the first direction E on the second sealing stud 400. The insulating wire 500 passes through the first through hole 301 and the second through hole 401, respectively, from the first sealing stud 300 to the second sealing stud 400. The two ends of the insulating wire 500 are respectively wound on the first winding post 302 and the second winding post 402 and then fixed. This not only prevents the ignition wire from excessively sagging between the two electrodes and exceeding the allowable range of coaxiality, but also avoids the generation of large debris after the experiment. After the experiment, if the insulating wire 500 breaks, it can be directly removed. Even if there is debris, it can be easily blown by the airflow to a position at the end of the tube of the deflagration drive section 1 for easy cleaning. At the same time, the first sealing stud cooperates with the first sealing cap, and the second sealing stud cooperates with the second sealing cap, effectively ensuring the airtightness within the deflagration drive section and being able to withstand high pressure. It should be noted that the deflagration driving technology requires that two electrodes be plugged into both ends of the deflagration driving section 1 , and an ignition wire is arranged between the two electrodes along the axis of the deflagration driving section 1 .

[0058] Optionally, the diameters of the first through hole 301 and the second through hole 401 are 5-10 mm respectively.

[0059] If the diameters of the first through hole 301 and the second through hole 401 are respectively less than 5 mm, the wire threading operation is difficult. If the diameters of the first through hole 301 and the second through hole 401 are respectively greater than 10 mm, it is unnecessary and the structure becomes too bulky. Therefore, the diameters of the first through hole 301 and the second through hole 401 are respectively 5-10 mm, which not only allows the insulating wire 500 to pass through the first through hole 301 and the second through hole 401, but also ensures a light structure.

[0060] Optionally, the diameters of the first winding pole 302 and the second winding pole 402 are respectively 3-6 mm.

[0061] If the diameters of the first winding pole 302 and the second winding pole 402 are respectively higher than 6, the structure will be bulky; if the diameters of the first winding pole 302 and the second winding pole 402 are respectively lower than 3 mm, it will be inconvenient for winding and fixing operations. Therefore, the diameters of the first winding pole 302 and the second winding pole 402 are respectively designed to be 3-6 mm, which is convenient for operation and ensures a light structure.

[0062] Figure 6 Schematic diagram of the structure of a coaxial cylindrical deflagration drive device for a shock tube / wind tunnel provided by an embodiment of the present invention; Figure 7 yes Figure 6 A magnified view of the structure at point B in the middle; Figure 8 yes Figure 6 A magnified diagram of the structure of the discharge system; Figure 9 This is a logic block diagram of a discharge system provided by an embodiment of the present invention. Figure 6-Figure 9 As shown, this embodiment provides a coaxial cylindrical deflagration drive device for a shock tube / wind tunnel, comprising a deflagration drive section 1, a driven section 2, a diaphragm 5 for separating the deflagration drive section 1 from the driven section 2, a blind plate 14, and a discharge system 7. One end of the deflagration drive section 1 is connected to the driven section 2, and the other end is connected to the blind plate 14.

[0063] The deflagration driving section 1 is a straight tube of uniform cross-section. A first electrode 11 and a second electrode 12 extending along a radial direction Y are connected to the deflagration driving section 1. The first electrode 11 is located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 is located on the side of the deflagration driving section 1 close to the driven section 2. An ignition wire 13 extending along an axial direction X is electrically connected between the first electrode 11 and the second electrode 12. The axial direction X is the direction of the axial centerline from the deflagration driving section 1 to the driven section 2, and the radial direction Y intersects the axial direction X.

[0064] Along the axial direction X, the length between the first electrode 11 and the blind plate 14 is L1, and the length between the second electrode 12 and the diaphragm 5 is L2. The lengths of L1 and L2 are limited to 0.5 cm-20 cm.

[0065] The deflagration driving section 1 is provided with an opening 8 that matches the first electrode 11 and the second electrode 12. A sealing ring 81 is provided on the contact surface between the first electrode 11 and the second electrode 12 and the opening 8.

[0066] An ignition wire flexible support ring 1000 is also installed on the deflagration drive section 1;

[0067] The deflagration driving section 1 is filled with combustible mixed gas;

[0068] The discharge system 7 includes a high-voltage capacitor 71, an ignition switch 720 and a unloading switch 730. The ignition circuit 72 is composed of the positive electrode of the high-voltage capacitor 71, the ignition switch 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative electrode of the high-voltage capacitor 71; the unloading circuit 73 is composed of the positive electrode of the high-voltage capacitor 71, the unloading switch 730 and the negative electrode of the high-voltage capacitor 71; the ignition circuit 72 and the unloading circuit 73 are connected in parallel, and the high-voltage capacitor 71 is used to store high voltage electricity and discharge it to the ignition wire.

[0069] Specifically, the coaxial cylindrical deflagration drive device for a shock tube / wind tunnel includes a deflagration drive section 1 and a driven section 2. One end of the deflagration drive section 1 is connected to the driven section 2, and the other end is connected to a blind plate 14. A diaphragm 5 is provided between the deflagration drive section 1 and the driven section 2. The driven section 2 is connected to a test section 4 through a nozzle 3. The blind plate 14 is a flange cover. The blind plate 14 is used to block the end of the deflagration drive section 1, eliminating the need for a traditional explosion unloading section and the provision of a diaphragm between the explosion unloading section and the deflagration drive section. This not only helps to reduce the occupied space area, but also reduces costs.

[0070] A first electrode 11 and a second electrode 12 extending along a radial direction Y are plugged into the deflagration driving segment 1, the first electrode 11 being located on a side of the deflagration driving segment 1 close to the blind plate 14, and the second electrode 12 being located on a side of the deflagration driving segment 1 close to the driven segment 2, that is, the first electrode 11 and the second electrode 12 are plugged into both ends of the deflagration driving segment 1; an ignition wire 13 extending along an axial direction is electrically connected between the first electrode 11 and the second electrode 12, the axial direction X being the direction from the blind plate 14 to the axial centerline of the driven segment 2, the radial direction Y intersecting the axial direction X, optionally, the ignition wire 13 can be made of any metal material selected from copper, silver, nickel-chromium, tungsten and alloys, and the length of the ignition wire 13 can be adjusted according to the length of the deflagration driving segment 1;

[0071] The axial distance from the first electrode 11 to the blind plate 14 is L1, and the axial distance from the second electrode 12 to the diaphragm 5 is L2. If the lengths of L1 and L2 are less than 0.5 cm, breakdown may occur, resulting in damage to the equipment or endangering the safety of personnel; if the lengths of L1 and L2 are greater than 20 cm, it may cause unstable combustion of the combustible mixture in the deflagration driving section 1. Therefore, the lengths of L1 and L2 are limited to 0.5 cm-20 cm. This not only makes the ignition wire 13 as long as possible in the axial direction in the deflagration driving section, which can further make the combustible mixture in the deflagration driving section 1 burn more fully, but also avoids the distances between the first electrode 11 and the end of the deflagration driving section and between the second electrode 12 and the diaphragm 5 being too close, thereby avoiding breakdown and ensuring the safety of equipment and personnel.

[0072] Figure 3 yes Figure 2 A magnified view of the structure at point B in the middle; Figure 2 The enlarged view of point C is the same as that of point B. The deflagration driving section 1 is provided with an opening 8 that matches the first electrode 11 and the second electrode 12. Figure 7In order to show the opening 8 in the figure, the aperture of the opening 8 is drawn larger than the actual size. The opening 8 cooperates with the first electrode 11, and the second electrode 12 cooperates with the opening 8. The opening 8 facilitates the insertion of the first electrode 11 and the second electrode 12 into the combustion driving segment 1. In order to ensure the sealing inside the deflagration driving segment 1, after the first electrode 11 is inserted into the deflagration driving segment 1, a sealing ring 81 is provided on the contact surface of the deflagration driving segment 1 where the first electrode 1 contacts the opening 8, and a sealing ring 81 is provided on the contact surface of the deflagration driving segment 1 where the second electrode 12 contacts the opening 8;

[0073] A flexible ignition wire support ring 1000 is also installed on the deflagration drive section 1. The flexible ignition wire support ring 1000 is located in the middle section of the deflagration drive section 1. The flexible ignition wire support ring 1000 is the rigid ignition wire support ring for the coaxial cylindrical deflagration drive device described above. It should be noted that the first direction E of the rigid ignition wire support ring for the coaxial cylindrical deflagration drive device intersects the axial direction X and the radial direction Y respectively. After the flexible ignition wire support ring 1000 is installed, the insulating wire not only prevents the ignition wire 13 from excessively sagging between the first electrode 11 and the second electrode 12, thereby exceeding the allowable range of coaxiality, but also avoids the generation of large debris after the experiment.

[0074] The deflagration driving section 1 is filled with a combustible mixed gas, which may include a fuel, an oxidant and an inert gas, wherein the fuel is hydrogen, carbon monoxide or alkanes, alkenes and alkynes, or other combustible gases; the oxidant is oxygen or nitrous oxide, or other oxidizing gases; the inert gas is nitrogen, a rare gas or carbon dioxide, or other gases that do not participate in the combustion reaction; the ratio of fuel:oxidant:inert gas may be 1:1:1, the ratio of fuel:oxidant:inert gas may be 2:1:1, and the ratio of fuel:oxidant:inert gas may be 2:1:7. Of course, the ratio of fuel, oxidant and inert gas is set according to the specific equipment and experimental requirements;

[0075] The ignition system further includes a discharge system 7, which includes a high-voltage capacitor 71, an ignition switch 720, and an unloading switch 730. The positive electrode of the high-voltage capacitor 71, the ignition switch 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative electrode of the high-voltage capacitor 71 constitute an ignition circuit 72; the positive electrode of the high-voltage capacitor 71, the unloading switch 730, and the negative electrode of the high-voltage capacitor 71 constitute an unloading circuit 73. The ignition circuit 72 and the unloading circuit 73 are connected in parallel. The high-voltage capacitor 71 is used to store high voltage electricity.

[0076] After the high-voltage capacitor 71 is charged, the ignition switch 720 is closed first, and the high-voltage capacitor 71 is connected to the ignition wire 13 through the first electrode 11 and the second electrode 12 respectively, and ignition begins; after a predetermined time, the unloading switch 730 is closed to short-circuit the positive and negative poles of the high-voltage capacitor 71, and the charge in the high-voltage capacitor 71 is instantly returned to the high-voltage capacitor 71 through the unloading circuit 73, completing the unloading. The above-mentioned predetermined time can be 5-30 milliseconds.

[0077] The assembly sequence for the coaxial cylindrical deflagration drive device for shock tubes / wind tunnels is as follows:

[0078] First, providing a deflagration drive section 1;

[0079] Second, first, an opening 8 for placing the first electrode 11 and the second electrode 12 is opened on the deflagration driving section 1; second, a sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and the first electrode 11 and the second electrode 12 are inserted into the opening 8, with the first electrode 11 located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 located on the side of the deflagration driving section 1 close to the driven section 2; an ignition wire 13 extending along the axial direction X is connected between the first electrode 11 and the second electrode 12;

[0080] Third, an ignition wire flexible support ring 1000 is installed in the middle section of the deflagration drive section 1;

[0081] Fourth, a diaphragm is installed between the deflagration driving section 1 and the driven section 2. The driven section 2 is connected to one end of the deflagration driving section 1 close to the diaphragm 5, and the other end is connected to a blind plate 14.

[0082] Fifth, the deflagration driving section 1 is filled with combustible mixed gas;

[0083] Sixth, connect the discharge system 7, and the positive electrode of the high-voltage capacitor 71, the ignition switch 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative electrode of the high-voltage capacitor 71 constitute an ignition circuit 72; the positive electrode of the high-voltage capacitor 71, the unloading switch 730, and the negative electrode of the high-voltage capacitor 71 constitute an unloading circuit 73; the ignition circuit 72 and the unloading circuit 73 are connected in parallel.

[0084] Assembling the coaxial cylindrical deflagration drive device for shock tube / wind tunnel according to the above assembly sequence can not only better connect the first electrode and the second electrode, making the position of the ignition wire 13 more accurately arranged, but also avoid leakage of the combustible mixture, ensure personal safety, and facilitate operation.

[0085] Of course, without considering the discharge of the high-voltage capacitor to the ignition wire, the above assembly sequence can be adjusted appropriately. After installing the driven section 2 or the blind plate 14, the discharge system can be connected first, and then the combustible mixture can be filled into the deflagration driving section 1, as follows:

[0086] First, providing a deflagration drive section 1;

[0087] Second, first, an opening 8 for placing the first electrode 11 and the second electrode 12 is opened on the deflagration driving section 1; second, a sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and the first electrode 11 and the second electrode 12 are inserted into the opening 8, with the first electrode 11 located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 located on the side of the deflagration driving section 1 close to the driven section 2; an ignition wire 13 extending along the axial direction X is connected between the first electrode 11 and the second electrode 12;

[0088] Third, an ignition wire flexible support ring 1000 is installed in the middle section of the deflagration drive section 1;

[0089] Fourth, a diaphragm is installed between the deflagration driving section 1 and the driven section 2. The driven section 2 is connected to one end of the deflagration driving section 1 close to the diaphragm 5, and the other end is connected to a blind plate 14.

[0090] Fifth, connect the discharge system 7, and connect the positive electrode of the high-voltage capacitor 71, the ignition switch 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative electrode of the high-voltage capacitor 71 to form an ignition circuit 72; connect the positive electrode of the high-voltage capacitor 71, the unloading switch 730, and the negative electrode of the high-voltage capacitor 71 to form an unloading circuit 73; and connect the ignition circuit 72 and the unloading circuit 73 in parallel;

[0091] Fifth, the deflagration driving section 1 is filled with combustible mixed gas.

[0092] It should be noted that: first, a deflagration driving section 1 is provided; second, first, an opening 8 for placing a first electrode 11 and a second electrode 12 is opened on the deflagration driving section 1; secondly, a sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and the first electrode 11 and the second electrode 12 are inserted into the opening 8, the first electrode 11 is located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 is located on the side of the deflagration driving section 1 close to the driven section 2; an ignition wire 13 extending along the axial direction X is connected between the first electrode 11 and the second electrode 12; third, an ignition wire flexible support ring 1000 is installed in the middle section of the deflagration driving section 1; fourth, a diaphragm is installed between the deflagration driving section 1 and the driven section 2, and the driven section 2 is connected to one end of the deflagration driving section 1 close to the diaphragm 5, and the other end is connected to the blind plate 14; the assembly order of the above four steps is irreversible, that is, the above assembly order cannot be reversed, and it cannot be implemented after reversal.

[0093] The working principle is as follows: There is an ignition wire 13 arranged along the axial direction X in the deflagration driving section 1. After the high-voltage capacitor 71 is charged, the ignition switch 720 is closed first. The high-voltage capacitor 71 is connected to the ignition wire 13 through the first electrode 11 and the second electrode 12 respectively. A high voltage of thousands to tens of thousands of volts is applied to both ends of the ignition wire 13. When the ignition switch 720 is energized, the ignition wire 13 heats up violently, igniting the combustible mixture near the ignition wire 13 within microseconds. After ignition, a columnar flame is formed and expands radially. The ignition wire 13 is strictly coaxial with the pipeline of the deflagration drive section 1 to ensure that they are burned out simultaneously at all locations along the axial direction; since the discharge process of the high-voltage capacitor 71 is longer than the combustion process, the remaining charge in the high-voltage capacitor 71 needs to be unloaded before the end of combustion. Therefore, after a predetermined time, the unloading switch 730 is closed to short-circuit the positive and negative poles of the high-voltage capacitor 71. The charge in the high-voltage capacitor 71 is instantly returned to the high-voltage capacitor 71 through the unloading circuit, completing the unloading, thereby preventing the combustion products from breaking down near the positive pole of the high-voltage capacitor 71 and causing a safety accident.

[0094] It should be noted that detonation drive requires the formation of a detonation wave that propagates axially in the drive section pipeline, while deflagration drive causes the gas in the pipeline of the deflagration drive section 1 to ignite simultaneously along the axial direction, completing combustion in a deflagration rather than detonation manner, and ending combustion simultaneously along the axial direction X.

[0095] Typically, the effective operating time of a shock tube / wind tunnel is on the order of a few milliseconds to 100 milliseconds. In order to provide precise test conditions, it is necessary to strictly ensure that the combustible mixture in the deflagration drive section is ignited and burned out at the same time.

[0096] It can be seen from the above embodiments that the coaxial cylindrical deflagration drive device for shock tubes / wind tunnels provided by the present invention achieves at least the following beneficial effects:

[0097] First, in the prior art, detonation drives a detonation wave that propagates axially within the driving section pipe. However, since the extremely high pressure peak of the detonation wave cannot be fully utilized for driving, the effective pressure provided by the detonation drive is significantly lower than the pressure limit of the equipment. In contrast, the present invention replaces detonation with deflagration, eliminating the pressure peak associated with detonation. 100% of the combustion pressure can be used to compress the test gas, thereby increasing the pressure of the test gas.

[0098] Second, the mixture ratio limit of deflagration is much wider than that of detonation, and the temperature and sound speed range of the driving gas is larger. Therefore, the corresponding total temperature range of the test gas is also larger than that of detonation driving.

[0099] Third, the flexible support ring for the ignition wire not only prevents the ignition wire from sagging excessively between the first electrode and the second electrode, exceeding the allowable range of coaxiality, but also avoids the generation of large debris after the experiment. At the same time, it effectively ensures the airtightness within the deflagration drive section and can withstand high pressure.

[0100] Figure 10 Schematic diagram of the structure of a shock tube / wind tunnel provided by an embodiment of the present invention; another embodiment of the present invention provides a shock tube / wind tunnel, including a coaxial cylindrical deflagration drive device for a shock tube / wind tunnel provided by an embodiment of the present invention.

[0101] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A flexible support ring for an ignition wire used in a coaxial cylindrical deflagration drive device, characterized in that: It includes a deflagration drive section and an insulating wire, wherein the deflagration drive section has a pipeline; The deflagration drive section is provided with at least three mounting holes along a circumferential direction, wherein the at least three mounting holes include a first sub-hole, a second sub-hole, and a third sub-hole, wherein the first sub-hole and the second sub-hole are arranged opposite to each other along a first direction, and the first direction is a direction from the first sub-hole to the second sub-hole; A first sealing stud is installed on the first sub-hole, a first through hole extending along the first direction is opened on the first sealing stud, a first winding post is provided on the side of the first sealing stud away from the pipe, and the first winding post is not coaxial with the first through hole; A second sealing stud is installed on the second sub-hole, a second through hole extending along the first direction is opened on the second sealing stud, a second winding post is provided on the side of the second sealing stud away from the pipe, and the second winding post is not coaxial with the second through hole; The insulating wire passes through the first through hole and the second through hole in sequence from the first sealing stud to the second sealing stud, wherein one end of the insulating wire is connected to the first winding post, and the other end of the insulating wire is connected to the second winding post; The first sealing stud is covered with a first sealing cap at one end away from the pipe, and the second sealing stud is covered with a second sealing cap at one end away from the pipe; The third sub-hole is located between the first sub-hole and the second sub-hole.

2. The ignition wire flexible support ring for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The diameters of the first through hole and the second through hole are 5-10 mm respectively.

3. The ignition wire flexible support ring for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The diameters of the first winding pin and the second winding pin are 3-6 mm respectively.

4. The ignition wire flexible support ring for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The insulating wire is made of polytetrafluoroethylene, polyamide or phenylenediamine.

5. The ignition wire flexible support ring for a coaxial cylindrical deflagration drive device according to any one of claims 1 to 4, characterized in that: The third sub-hole is located below the deflagration driving section.

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