Rotating sonic nozzle for coaxial cylindrical deflagration drive

Abstract

The present invention discloses a rotary sonic nozzle for a coaxial cylindrical deflagration drive device, comprising an air inlet cap, an air outlet cap, and an orifice plate; the air inlet cap is provided with an air inlet channel having a first air inlet section and a first air outlet section; the air outlet cap is provided with an air outlet channel having a second air inlet section and a second air outlet section; the orifice plate is located between the air inlet cap and the air outlet cap; the orifice plate is provided with small holes, each of which has a different diameter; the diameter of the small holes on the orifice plate gradually decreases along the circumferential direction; the air inlet cap is provided with a contact protrusion; the air outlet cap is provided with a contact groove; the contact protrusion has multiple first protruding surfaces, the edge of the orifice plate is provided with a second protruding surface, and the contact groove is provided with a concave surface that matches the first and second protruding surfaces. The present invention can limit the airflow velocity when charging the combustible mixed gas into the deflagration drive section, so that it meets the stringent requirements of the deflagration drive for the mixing uniformity of the combustible gas.

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 rotary sonic nozzle for 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] Due to the aforementioned problems with detonation drive, it is necessary to overcome them and introduce coaxial cylindrical deflagration drive technology. However, coaxial cylindrical deflagration drive technology requires that the deflagration drive section pipeline be filled with a specified ratio of combustible mixed gases, such as 2 hydrogen + 1 oxygen + 2 nitrogen. To accurately ensure the ratio of each gas component, a sonic nozzle needs to be installed in the filling pipeline of each gas. To ensure the flow rate of the sonic nozzle is accurate, the air pressure upstream of the nozzle must be greater than or equal to approximately twice the air pressure downstream of the nozzle. When the driving gas pressure required by the experiment is higher (such as 5MPa), the air pressure upstream of the sonic nozzle must always be no less than 10MPa. The higher the pre-sonic pressure, the greater the gas density and the greater the gas flow rate. On the one hand, since combustion-driven technology has stringent requirements on the uniformity of mixing of combustible gases, in order to mix the combustible gases as evenly as possible, the airflow velocity must be limited when filling the gas into the deflagration-driven section pipeline. This requires that the aperture of the sonic nozzle be very small, such as a diameter of 30μm-50μm, which cannot be achieved using traditional machining methods; on the other hand, as a scientific research and experimental equipment, the deflagration-driven shock tube / wind tunnel requires a large range of combustible gas mixture ratios. Traditional sonic nozzles have a single throat diameter, and the sonic nozzle must be replaced when the mixture ratio changes significantly. Each time the nozzle is disassembled and replaced, the calibration experiment needs to be carried out again, which is inefficient.

[0007] Existing document 1 (105328199B) discloses a new type of gas atomization nozzle, including a nozzle upper mold, the nozzle upper mold and the nozzle lower mold are connected, and an air channel including an air inlet cavity, an air storage cavity, an air flow contraction section, a nozzle throat and an air flow expansion section is formed between the nozzle upper mold and the nozzle lower mold from the outside to the inside. A cavity is provided in the middle of the nozzle upper mold and the nozzle lower mold, and a nozzle auxiliary part is provided in the cavity. The nozzle auxiliary part is used to heat and guide the liquid metal, improve the fluidity of the liquid metal, reduce the surface tension of the liquid metal, and provide the atomizing nozzle with liquid metal of appropriate viscosity, so as to facilitate the conversion of gas kinetic energy into liquid metal surface energy and facilitate smooth atomization; the nozzle upper mold includes a hollow cover section, a hollow cylindrical section, and a hollow frustum; wherein, the connection between the cylindrical section and the frustum is an inwardly concave arc transition section; the frustum is provided with a liquid guide tube inlet hole and a frustum hole, and the guide tube inlet hole and the frustum hole are provided with a transition annular platform, and the opening angle of the frustum is 0. The angle is 50-80 degrees; the hollow cylindrical section is located in the middle section of the nozzle upper die, and the outer cylindrical surface of the cylindrical section is provided with an external thread; the hollow cover section is located in the upper section of the nozzle upper die, and the transition between the cover section and the cylindrical section is a 90-degree circular platform, and the outer edge of the cover section is chamfered; the nozzle lower die includes a solid, a two-step cylindrical cavity, an upper conical cavity, a lower conical cavity, an air inlet channel and an air cavity; the two-step cylindrical cavity is located above the solid, and the inner wall of the second step of the cylindrical cavity is provided with an internal thread, and the first The steps are chamfered; the upper conical inner cavity is located below the two-step cylindrical inner cavity, the connection of the upper conical inner cavity is an outward convex arc transition section, and the opening angle of the upper conical inner cavity is 40-70 degrees; the lower conical inner cavity is located below the upper conical inner cavity, and the opening angle of the lower conical inner cavity is 40-70 degrees; the nozzle lower mold is provided with two air inlet channels, the center lines of which are in a straight line; the air cavity is located outside the upper conical inner cavity, and the air cavity is connected to the air inlet channel, but the above technical solution still cannot solve the above technical problems.

[0008] Existing document 2 (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 being provided with a detonation unloading section, and the other end being provided with a driven section; a first diaphragm being provided between the detonation unloading section and the detonation drive section, and a second diaphragm being provided between the driven section and the detonation drive section; a forward detonation drive ignition device being provided at a section of the detonation drive section close to the detonation unloading section, and a reverse detonation drive ignition device being provided at a section of the detonation drive section close to the driven section; a controllable time-delay triggering device being connected between the forward detonation drive ignition device and the reverse detonation drive ignition device, and the method thereof is as follows: 1) a forward detonation ignition device is provided at one end of the detonation drive section of the shock tunnel close to the detonation unloading section, and a reverse detonation drive ignition device is provided at one end of the detonation drive section close to the driven section;

[0009] 2) Ignition is performed through a forward detonation ignition device to form a forward-driven detonation wave; 3) After the forward detonation wave propagates along the detonation-driven section for a predetermined time, ignition is performed through a reverse detonation-driven ignition device to form a reverse-driven detonation wave; 4) The reverse-driven detonation wave tears the diaphragm provided between the driven section and the detonation-driven 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.

[0010] In order to meet the coaxial cylindrical deflagration drive technology, the present invention proposes a rotary sonic nozzle for a coaxial cylindrical deflagration drive device, and the rotary sonic nozzle for a coaxial cylindrical deflagration drive device is not easily conceived by those skilled in the art. Summary of the Invention

[0011] In view of this, the present invention provides a rotary sonic nozzle for a coaxial cylindrical deflagration drive device, comprising an air inlet cap, an air outlet cap and an orifice plate;

[0012] An air intake channel is provided on the air intake cap, and the air intake channel comprises a first air intake section and a first air outlet section connected to the first air intake section;

[0013] The outlet cap is provided with an outlet channel, the outlet channel having a plurality of second air inlet sections arranged in a circumferential direction and a second air outlet section connected to the second air inlet sections, the second air inlet sections being located on a side close to the air inlet cap, and the second air outlet section being located on a side away from the air inlet cap;

[0014] The first air outlet section corresponds to a second air inlet section on the air outlet channel;

[0015] The orifice plate is located between the air inlet cap and the air outlet cap, and the orifice plate is connected to the air outlet cap;

[0016] The orifice plate is provided with small holes along the circumferential direction that match the second air inlet section, each of the small holes having a different diameter. The small holes are coaxial with the second air inlet section along a first direction, where the first direction is the direction from the air inlet cap to the air outlet cap.

[0017] The diameter of each of the small holes is smaller than the diameter of the corresponding second air inlet section;

[0018] The diameter of the small holes on the orifice plate gradually decreases along the circumferential direction;

[0019] The diameter of some of the pores is 30 μm-50 μm;

[0020] The air inlet cap is provided with a contact protrusion on one side close to the air outlet cap; the air outlet cap is provided with a contact groove matching the contact protrusion on one side close to the air inlet cap; the contact protrusion, the contact groove and the orifice plate are all in the shape of regular polygons;

[0021] The contact protrusion has a plurality of first convex surfaces, the edge of the orifice plate is provided with a second convex surface, and the contact groove is provided with a concave surface matching the first convex surface and the second convex surface;

[0022] A first sealing ring is installed on the contact surface between the second air inlet section and the orifice plate; a second sealing ring corresponding to the first sealing ring is installed on the contact surface between the contact protrusion and the orifice plate, wherein one of the second sealing rings is sleeved on the first air outlet section;

[0023] The air outlet cap and the air inlet cap are connected via a locking nut.

[0024] Optionally, the air outlet cap is connected to the orifice plate via a screw, the screw comprises a screw rod and a nut connected to the screw rod, and a blind hole cooperating with the nut is provided on the side of the air inlet cap close to the air outlet cap.

[0025] Optionally, the first air outlet section includes a first sub-air outlet section and a second sub-air outlet section connected to the first sub-air outlet section, the first sub-air outlet section is located on the side away from the air outlet cap, and the second sub-air outlet section is located on the side close to the air outlet cap; the first sub-air outlet section is connected to the first air inlet section, and the first air inlet section and the second sub-air outlet section are not coaxial.

[0026] Optionally, the second air outlet section includes a first mixing tube section and a second mixing tube section connected to the first mixing tube section, the first mixing tube section is located close to the second air inlet section, the second mixing tube section is located away from the second air inlet section, and multiple second air inlet sections are all connected to the first mixing tube section.

[0027] Optionally, a first groove corresponding to the second sealing ring is provided on the contact protrusion, and a second groove surrounding the second air inlet section is provided on the contact groove;

[0028] The second sealing ring on the contact surface between the contact protrusion and the orifice plate is located in the first groove, and the first sealing ring on the contact surface between the second air inlet section and the orifice plate is located in the second groove.

[0029] Optionally, along the first direction, the thickness of the orifice plate is 300 μm-500 μm.

[0030] Compared with the prior art, the rotary sonic nozzle for a coaxial cylindrical deflagration drive device provided by the present invention achieves at least the following beneficial effects:

[0031] On the one hand, the air inlet channel on the air inlet cap, the small holes on the orifice plate, and the air outlet channel on the air outlet cap cooperate with each other. Among them, the diameter of some small holes is between 30μm and 50μm. This can limit the air flow velocity when the combustible mixed gas is charged into the deflagration drive section, so that it meets the strict requirements of the deflagration drive for the mixing uniformity of the combustible gas, thereby achieving the most uniform mixing of the combustible gas.

[0032] On the other hand, by designing the contact protrusion on the air inlet cap, the orifice plate and the contact groove on the air outlet cap to be regular polygons that fit together, the first convex surface on the contact protrusion and the concave surface on the contact groove are matched with each other, and the second convex surface on the orifice plate and the concave surface on the contact groove are matched with each other, that is to say: the contact positions of the air inlet cap, the orifice plate and the air outlet cap are designed to be regular polygons that fit together, and they can only be reinserted when the angle is correct, thereby facilitating the rotation operation. At the same time, there is no need to re-calibrate the test each time the sonic nozzle is disassembled and replaced, thereby improving efficiency.

[0033] 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.

[0034] 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

[0035] 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.

[0036] Figure 1 This is a schematic diagram of the structure of a shock tube / wind tunnel provided in the prior art;

[0037] Figure 2 Schematic diagram of the structure of a rotary sonic nozzle for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

[0038] Figure 3 yes Figure 2 Cross-sectional view of middle AA;

[0039] Figure 4 This is an exploded view of a rotary sonic nozzle for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

[0040] Figure 5 1 is a schematic structural diagram of an air intake cap provided by an embodiment of the present invention;

[0041] Figure 6 is a bottom view of the air intake cap provided by an embodiment of the present invention;

[0042] Figure 7 1 is a schematic structural diagram of an air outlet cap provided in an embodiment of the present invention;

[0043] Figure 8 Schematic diagram of the structure of the orifice plate provided in an embodiment of the present invention;

[0044] Figure 9 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;

[0045] Figure 10 yes Figure 9 A magnified view of the structure at point B in the middle;

[0046] Figure 11 yes Figure 9 A magnified diagram of the structure of the discharge system;

[0047] Figure 12 This is a logic block diagram of a discharge system provided by an embodiment of the present invention;

[0048] Figure 13 Schematic diagram of the structure of a shock tube / wind tunnel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Figure 21 is a schematic structural diagram of a rotary sonic nozzle for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention; Figure 3 yes Figure 2 Cross-sectional view of middle AA; Figure 4 This is an exploded view of a rotary sonic nozzle for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention; Figure 5 1 is a schematic structural diagram of an air intake cap provided by an embodiment of the present invention; Figure 6 is a bottom view of the air intake cap provided by an embodiment of the present invention; Figure 7 1 is a schematic structural diagram of an air outlet cap provided in an embodiment of the present invention; Figure 8 is a schematic structural diagram of the orifice plate provided in an embodiment of the present invention; see Figure 2-8 As shown, this embodiment provides a rotary sonic nozzle 1000 for a coaxial cylindrical deflagration drive device, comprising an air inlet cap 100, an air outlet cap 200 and an orifice plate 300;

[0055] An air inlet channel 101 is formed on the air inlet cap 100. The air inlet channel 101 includes a first air inlet section 102 and a first air outlet section 103 communicating with the first air inlet section 102.

[0056] The air outlet cap 200 is provided with an air outlet channel 201. The air outlet channel 201 has a plurality of second air inlet sections 202 arranged in a circumferential direction and a second air outlet section 203 communicating with the second air inlet sections 202. The second air inlet sections 202 are located near the air inlet cap 100, and the second air outlet section 203 is located away from the air inlet cap 100.

[0057] The first air outlet section 103 corresponds to the second air inlet section 202 on the air outlet channel 201;

[0058] The orifice plate 300 is located between the air inlet cap 100 and the air outlet cap 200, and the orifice plate 300 is connected to the air outlet cap 200;

[0059] The orifice plate 300 is provided with small holes 301 along the circumferential direction, which cooperate with the second air inlet section 202. The diameters of each small hole 301 are different. Along the first direction E, the small hole 301 is coaxial with the second air inlet section 202. The first direction E is the direction from the air inlet cap 100 to the air outlet cap 200.

[0060] The diameter of each small hole 301 is smaller than the diameter of the corresponding second air inlet section 202;

[0061] The diameter of the small hole 301 on the orifice plate 300 gradually decreases along the circumferential direction;

[0062] The diameter of some of the small holes 301 is 30 μm-50 μm;

[0063] The air inlet cap 100 is provided with a contact protrusion 104 on the side close to the air outlet cap 200; the air outlet cap 200 is provided with a contact groove 204 that matches the contact protrusion 104 on the side close to the air inlet cap 100; the contact protrusion 104, the orifice plate 300 and the contact groove 204 are all regular polygons;

[0064] The contact block has a plurality of first protruding surfaces 105 , the edge of the orifice plate 300 is provided with a second protruding surface 303 , and the contact groove 204 is provided with a concave surface 205 that matches the first protruding surface 105 and the second protruding surface 303 ;

[0065] A first sealing ring 700 is installed on the contact surface between the second air inlet section 202 and the orifice plate 300, and a second sealing ring 701 corresponding to the first sealing ring 700 is installed on the contact surface between the contact protrusion 104 and the orifice plate 300. One of the second sealing rings 701 is sleeved on the first air outlet section 103.

[0066] The air outlet cap 200 and the air inlet cap 100 are connected via a locking nut 400 .

[0067] Specifically, the rotary sonic nozzle 1000 for the coaxial cylindrical deflagration drive device includes an air inlet cap 100, an air outlet cap 200 and an orifice plate 300;

[0068] An air inlet channel 101 is provided on the air inlet cap 100. The air inlet channel 101 includes a first air inlet section 102 and a first air outlet section 103. The first air inlet section 102 and the first air outlet section 103 are connected. The air inlet cap 100 has an inner hole structure of "one inlet and one outlet". The shape of the air inlet channel 101 can be bent.

[0069] An air outlet channel 201 is provided on the air outlet cap 200. The air outlet channel 201 has a plurality of second air inlet segments 202 and second air outlet segments 203 arranged in a circumferential direction. The second air inlet segments 202 and the second air outlet segments 203 are connected. The second air inlet segments 202 are located on the side close to the air inlet cap 100, and the second air outlet segments 203 are located on the side away from the air inlet cap 100. There can be eight second air inlet segments 202. The air outlet cap 200 has a "multiple inlet and one outlet" internal hole structure. All second air inlet segments 202 converge into the same second air outlet segment 203. The first air outlet segment 103 is associated with a second air inlet segment 202 on the air outlet channel 201.

[0070] A perforated plate 300 is sandwiched between the air inlet cap 100 and the air outlet cap 200, and the perforated plate 300 is connected to the air outlet cap 200;

[0071] A plurality of small holes 301 of different diameters are formed on the orifice plate 300 along the circumferential direction. The plurality of small holes 301 cooperate with the plurality of second air inlet segments 202. Along a first direction E, the small holes 301 and the second air inlet segments 202 are coaxial. The first direction E is the direction from the air inlet cap 100 to the air outlet cap 200. In other words, each small hole 301 is coaxial with each second air inlet segment 202 on the air outlet cap 200.

[0072] The orifice plate 300 is a thin film orifice plate 300, which is made of steel foil and laser cutting technology. If the thickness of the orifice plate 300 is less than 300 μm, the strength of the orifice plate 300 is insufficient. If the thickness of the orifice plate 300 is greater than 500 μm, it is not conducive to maintaining the accuracy of laser cutting. Therefore, along the first direction E, the thickness of the orifice plate 300 can be 300 μm-500 μm.

[0073] In order to enable the film to withstand the huge pressure difference, the diameter of the second air inlet section 202 on the air outlet cap 200 is slightly larger than the diameter of the corresponding small hole 301 on the orifice plate 300, thereby effectively reducing the load on the orifice plate 300;

[0074] The diameter of the small holes 301 on the orifice plate 300 can gradually decrease along the circumferential direction. For example, the diameter of the small holes 301 on the orifice plate 300 can gradually decrease along the counterclockwise direction. By having different diameters of the small holes 301 on the orifice plate 300, different flow rates can be provided under the same pressure, thereby achieving flow adjustment.

[0075] When filling the deflagration driving section with combustible gas, the airflow velocity must be limited, and the diameter of the small holes on the orifice plate needs to be designed to be very small. In this solution, the diameter of some small holes 301 is designed to be 30μm-50μm, thereby extending the lower limit of the flow control range;

[0076] The cam 104 is provided with a contact protrusion 104 on the side of the air inlet cap 100 close to the air outlet cap 200, and the shape of the contact protrusion 104 is a regular polygon; the air outlet cap 200 is provided with a contact groove 204 that matches the contact protrusion 104 on the side of the air inlet cap 100 close to the air outlet cap 200, and the shape of the contact groove 204 is a regular polygon, and the shape of the orifice plate 300 is also a regular polygon; according to actual conditions, the shapes of the contact protrusion 104, the orifice plate 300 and the contact groove 204 can be designed to be a regular octagon, a regular heptagon or a regular hexagon respectively. Taking the regular octagon as an example, if the contact protrusion 104 on the air inlet cap 100 and the contact groove 204 on the air outlet cap 200 are both regular octagons, and the orifice plate 300 is also a regular octagon, the orifice plate 300 is placed on the air outlet cap 200. If the angle is not suitable, the orifice plate 300 can be placed on the contact groove 204 on the air outlet cap 200 by simply rotating the angle of the orifice plate 300, which is convenient for operation and has high work efficiency;

[0077] The contact protrusion 104 has multiple first protruding surfaces 105, the edge of the orifice plate 300 has a second protruding surface 303, and the contact groove 204 is provided with a concave surface 205 that matches the first protruding surface 105 and the second protruding surface 303. In order to ensure the accuracy of the angle of each rotation, the first protruding surface 105 on the contact protrusion 104 and / or the second protruding surface 303 on the orifice plate 300 are matched with the concave surface 205 on the contact groove 204. In other words, the contact position of the air inlet cap 100 and the air outlet cap 200 is designed to be a positive and deformable concave-convex match. It can only be reinserted when the angle is correct, thereby facilitating the rotation operation. At the same time, there is no need to re-calibrate the sonic nozzle after each disassembly and replacement, thereby improving work efficiency.

[0078] In order to achieve sealing upstream and downstream of the sonic nozzle, a first sealing ring 700 is respectively installed on the contact surface between the second air inlet section 202 and the orifice plate 300, and a second sealing ring 701 is installed on the contact surface between the contact protrusion 104 and the orifice plate 300. The first sealing ring 700 corresponds to the second sealing ring 701, that is, the second sealing ring 701 and the first sealing ring 700 are respectively installed above and below the orifice plate 300 corresponding to the second air inlet section 202, wherein one of the second sealing rings 701 is sleeved on the first air outlet section 103, and the first sealing ring 700 and the second sealing ring 701 are both O-shaped first sealing rings 700.

[0079] The air outlet cap 200 is connected to the air inlet cap 100 via a locking nut 400 .

[0080] During specific use, first connect the orifice plate 300 to the air outlet cap 200, and make the small hole 301 on the orifice plate 300 concentric with the second air inlet section 202 on the corresponding air outlet cap 200, and then tighten the air outlet cap 200 to the air inlet cap 100 through the locking nut 400 to achieve sealing, wherein the first air outlet section 103 on the air inlet cap 100 corresponds to a second air inlet section 202 on the air outlet cap 200. At this time, the combustible gas passes through this path and is intercepted by the corresponding small hole 301 on the orifice plate 300. When the diameter of the small hole 301 needs to be changed, loosen the locking nut 400 to separate the air inlet cap 100 and the air outlet cap 200, then rotate them to a specified angle, re-fit them, and then use the locking nut 400 to tighten the air inlet cap 100 and the air outlet cap 200.

[0081] It can be seen from the above embodiments that the rotary sonic nozzle for the coaxial cylindrical deflagration drive device provided by the present invention achieves at least the following beneficial effects:

[0082] On the one hand, the air inlet channel 101 on the air inlet cap 100, the small holes 301 on the orifice plate 300, and the air outlet channel 201 on the air outlet cap 200 cooperate with each other, wherein the diameter of some of the small holes 301 is between 30 μm and 50 μm, so that the air flow velocity can be limited when the combustible mixed gas is charged into the deflagration drive section, so that the combustible gas can be mixed as evenly as possible.

[0083] On the other hand, by designing the contact protrusion 104 on the air inlet cap 100, the orifice plate 300 and the contact groove 204 on the air outlet cap 200 as regular polygons that fit together, the first convex surface 105 on the contact protrusion 104 and the concave surface 205 on the contact groove 204 are matched with each other, and the second convex surface 303 on the orifice plate 300 and the concave surface 205 on the contact groove 204 are matched with each other, that is to say: the contact positions of the air inlet cap 100, the orifice plate 300 and the air outlet cap 200 are designed to be a regular polygon with deformable concave and convex fit, and they can only be reinserted when the angle is correct, thereby facilitating the rotation operation. At the same time, there is no need to re-calibrate the test each time the sonic nozzle is disassembled and replaced, thereby improving efficiency.

[0084] Optionally, the outlet cap 200 is connected to the orifice plate 300 via a screw 600 , which includes a screw rod 601 and a nut 602 connected to the screw rod 601 . The air inlet cap 100 is provided with a blind hole 106 on the side close to the outlet cap 200 that matches the nut 602 .

[0085] Specifically, a threaded hole 206 that cooperates with the screw 601 is provided at the center of the air outlet cap 200, a through hole 302 that cooperates with the threaded hole is provided on the orifice plate 300, the screw 601 on the screw 600 passes through the through hole and is threadedly connected to the threaded hole 206, and a blind hole 106 that cooperates with the nut 602 is provided on the air inlet cap 100. The orifice plate 300 is fixedly connected to the air outlet cap 200 by the screw 600, thereby preventing the orifice plate 300 from being stuck and deformed during rotation.

[0086] Optionally, the first air outlet section 103 includes a first sub-air outlet section 107 and a second sub-air outlet section 108 connected to the first sub-air outlet section 107, the first sub-air outlet section 107 is located on the side away from the air outlet cap 200, and the second sub-air outlet section 108 is located on the side close to the air outlet cap 200; the first sub-air outlet section 107 is connected to the first air inlet section 102, and the first air inlet section 102 and the second sub-air outlet section 108 are not coaxial.

[0087] Specifically, the first air outlet section 103 includes a first sub-air outlet section 107 and a second sub-air outlet section 108, and the first sub-air outlet section 107 and the second sub-air outlet section 108 are connected to each other. The first sub-air outlet section 107 is located on the side away from the air outlet cap 200, and the second sub-air outlet section 108 is located on the side close to the air outlet cap 200; the first sub-air outlet section 107 is connected to the first air inlet section 102, and along the first direction E, the first air inlet section 102 and the second sub-air outlet section 108 are not on the same horizontal plane, and an inverted L-shape is formed between the first sub-air outlet section 107 and the second sub-air outlet section 108. It can be understood that the entire air inlet channel 101 is bent. By adopting this solution, the overall structure can be made more compact.

[0088] Optionally, the second air outlet section 203 includes a first mixing tube section 207 and a second mixing tube section 208 connected to the first mixing tube section 207. The first mixing tube section 207 is located on the side close to the second air inlet section 202, and the second mixing tube section 208 is located on the side away from the second air inlet section 202. Multiple second air inlet sections 202 are all connected to the first mixing tube section 207. With this solution, the gas passing through each second air inlet section 202 is first mixed through the first mixing tube section 207 and then flows out from the second mixing tube section 208, making the overall structure more compact.

[0089] Optionally, the contact protrusion 104 is provided with a first groove 109 corresponding to the second sealing ring 701 , and the contact groove 204 is provided with a second groove 209 surrounding the second air inlet section 202 ;

[0090] The second sealing ring 701 on the contact surface between the contact bump 104 and the orifice plate 300 is located in the first groove 109 , and the first sealing ring 700 on the contact surface between the second air inlet section 202 and the orifice plate 300 is located in the first groove 109 and the second groove 209 respectively.

[0091] Specifically, a first groove 109 corresponding to the second sealing ring 701 is provided on the contact protrusion 104, and a second groove 209 surrounding the second air inlet section 202 is opened on the contact groove 204; a plurality of second sealing rings 701 are respectively installed in different first grooves 109, and the first sealing ring 700 on the contact surface between the second air inlet section 202 and the orifice plate 300 is placed in the second groove 209, that is, the second sealing ring 701 is installed in the first groove 109, and the second sealing ring 701 is in contact with the first sealing ring. The sealing rings 700 only need to correspond to each other, so that the contact surface between the first air outlet section 103 on the air inlet cap 100 and the orifice plate 300 is sealed, and multiple first sealing rings 700 are respectively installed in different second grooves 209, so that the contact surface between each second air inlet section 202 on the air outlet cap 200 and the orifice plate 300 is sealed, and the second sealing ring 701 and the first sealing ring 700 are respectively installed in the first groove 109 and the second groove 209, which can prevent the second sealing ring 701 and the first sealing ring 700 from shifting and achieve sealing more effectively.

[0092] It can be seen from the above embodiments that the rotary sonic nozzle for the coaxial cylindrical deflagration drive device provided by the present invention achieves at least the following beneficial effects:

[0093] On the one hand, the air inlet channel on the air inlet cap, the small holes on the orifice plate, and the air outlet channel on the air outlet cap cooperate with each other. Among them, the diameter of some small holes is between 30μm and 50μm. This can limit the air flow velocity when the combustible mixed gas is charged into the deflagration drive section, so that it meets the strict requirements of the deflagration drive for the mixing uniformity of the combustible gas, thereby achieving the most uniform mixing of the combustible gas.

[0094] On the other hand, by designing the contact protrusion on the air inlet cap, the orifice plate and the contact groove on the air outlet cap to be regular polygons that fit together, the first convex surface on the contact protrusion and the concave surface on the contact groove are matched with each other, and the second convex surface on the orifice plate and the concave surface on the contact groove are matched with each other, that is to say: the contact positions of the air inlet cap, the orifice plate and the air outlet cap are designed to be regular polygons that fit together, and they can only be reinserted when the angle is correct, thereby facilitating the rotation operation. At the same time, there is no need to re-calibrate the test each time the sonic nozzle is disassembled and replaced, thereby improving efficiency.

[0095] Figure 9 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 10 yes Figure 9 A magnified view of the structure at point B in the middle; Figure 11 yes Figure 9 A magnified diagram of the structure of the discharge system; Figure 12 This is a logic block diagram of a discharge system provided by an embodiment of the present invention. Figures 9-12As 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.

[0096] 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.

[0097] 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.

[0098] The deflagration driving section 1 is provided with an opening 8 that matches the first electrode 11 and the second electrode 12. A third sealing ring 81 is provided on the contact surface between the first electrode 11 and the second electrode 12 and the opening 8.

[0099] At least two groups of inflation pipes 9 are connected to the deflagration driving section 1, wherein one group of inflation pipes 9 is located on the side of the driven section 2 close to the diaphragm 5, and the remaining group of inflation pipes 9 is located on the side of the deflagration driving section 1 close to the blind plate 14. Each group of inflation pipes 9 is equipped with a sonic nozzle 1000;

[0100] The deflagration driving section 1 is filled with combustible mixed gas through the charging pipeline 9;

[0101] 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.

[0102] 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.

[0103] 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;

[0104] 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.

[0105] Figure 10 yes Figure 9 A magnified view of the structure at point B in the middle; Figure 9 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 10In 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 third 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 third sealing ring 81 is provided on the contact surface of the deflagration driving segment 1 where the second electrode 12 contacts the opening 8;

[0106] At least two groups of inflation pipes 9 are connected to the deflagration driving section 1, wherein one group of inflation pipes 9 is located on the side of the driven section 2 close to the diaphragm 5, and the remaining group of inflation pipes 9 is located on the side of the deflagration driving section 1 close to the blind plate 14. Each group of inflation pipes 9 is equipped with a sonic nozzle 1000, which is the rotary sonic nozzle used in the coaxial cylindrical deflagration driving device mentioned above;

[0107] At least two groups of charging pipes 9 are used to charge the deflagration driving section 1 and the driven section 2 with a combustible mixed gas, respectively. The combustible mixed gas may include fuel, oxidant and 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, 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.

[0108] 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.

[0109] 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.

[0110] The assembly sequence for the coaxial cylindrical deflagration drive device for shock tubes / wind tunnels is as follows:

[0111] First, providing a deflagration drive section 1;

[0112] Second, first, an opening 8 is opened on the deflagration driving section 1 for placing the first electrode 11 and the second electrode 12; second, a third sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and then 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;

[0113] Third, connect at least two sets of inflation pipes 9 to the deflagration driving section 1 and the driven section 2, respectively. One set of inflation pipes 9 is installed on the driven section 2 near the diaphragm 5, and the remaining set of inflation pipes 9 is installed on the deflagration driving section 1 near the blind plate 14. Each set of inflation pipes 9 is equipped with a sonic nozzle 1000.

[0114] 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.

[0115] Fifth, use at least two sets of gas charging pipes 9 to charge the required gas into the explosion driving section 1 and the driven section 2 respectively;

[0116] 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.

[0117] 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.

[0118] 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:

[0119] First, providing a deflagration drive section 1;

[0120] Second, first, an opening 8 is opened on the deflagration driving section 1 for placing the first electrode 11 and the second electrode 12; second, a third sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and then 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;

[0121] Third, connect at least two sets of inflation pipes 9 to the deflagration driving section 1 and the driven section 2, respectively. One set of inflation pipes 9 is installed on the driven section 2 near the diaphragm 5, and the remaining set of inflation pipes 9 is installed on the deflagration driving section 1 near the blind plate 14. Each set of inflation pipes 9 is equipped with a sonic nozzle 1000.

[0122] 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.

[0123] 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;

[0124] Sixth, at least two sets of gas charging pipelines 9 are used to charge the required gas into the explosion driving section 1 and the driven section 2 respectively.

[0125] 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; second, a third sealing ring 81 is installed on the contact surface of the first electrode 11 and the second electrode 12 with the opening 8, and then 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, at least Two groups of inflation pipes 9 are respectively connected to the deflagration driving section 1 and the driven section 2, wherein one group of inflation pipes 9 is installed on the side of the driven section 2 close to the diaphragm 5, and the remaining group of inflation pipes 9 is installed on the side of the deflagration driving section 1 close to the blind plate 14, and each group of inflation pipes 9 is respectively equipped with a sonic nozzle 1000; fourth, a diaphragm is installed between the deflagration driving section 1 and the driven section 2, and the driven section 2 is connected at 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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:

[0130] 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.

[0131] 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.

[0132] Third, the air inlet channel on the air inlet cap, the small holes on the orifice plate, and the air outlet channel on the air outlet cap cooperate with each other. Among them, the diameter of some small holes is between 30μm and 50μm. This can limit the air flow velocity when charging the combustible mixture into the deflagration drive section, so that it meets the stringent requirements of the deflagration drive for the mixing uniformity of the combustible gas, thereby achieving the most uniform mixing of the combustible gas.

[0133] Fourth, by designing the contact protrusion on the air inlet cap, the orifice plate and the contact groove on the air outlet cap to be regular polygons that fit each other, the first convex surface on the contact protrusion and the concave surface on the contact groove are matched with each other, and the second convex surface on the orifice plate and the concave surface on the contact groove are matched with each other, that is to say: the contact positions of the air inlet cap, the orifice plate and the air outlet cap are designed to be regular polygons with deformable concave and convex fits, and they can only be reinserted when the angle is correct, thereby facilitating the rotation operation. At the same time, there is no need to re-calibrate the test each time the sonic nozzle is disassembled and replaced, thereby improving efficiency.

[0134] Figure 13 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.

[0135] 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 rotary sonic nozzle for a coaxial cylindrical deflagration drive device, characterized in that: Including air inlet cap, air outlet cap and orifice plate; An air intake channel is provided on the air intake cap, and the air intake channel comprises a first air intake section and a first air outlet section connected to the first air intake section; The outlet cap is provided with an outlet channel, the outlet channel having a plurality of second air inlet sections arranged in a circumferential direction and a second air outlet section connected to the second air inlet sections, the second air inlet sections being located on a side close to the air inlet cap, and the second air outlet section being located on a side away from the air inlet cap; The first air outlet section corresponds to a second air inlet section on the air outlet channel; The orifice plate is located between the air inlet cap and the air outlet cap, and the orifice plate is connected to the air outlet cap; The orifice plate is provided with small holes along the circumferential direction that match the second air inlet section, each of the small holes having a different diameter. The small holes are coaxial with the second air inlet section along a first direction, where the first direction is the direction from the air inlet cap to the air outlet cap. The diameter of each of the small holes is smaller than the diameter of the corresponding second air inlet section; The diameter of the small holes on the orifice plate gradually decreases along the circumferential direction; The diameter of some of the pores is 30 μm-50 μm; The air inlet cap is provided with a contact protrusion on one side close to the air outlet cap; the air outlet cap is provided with a contact groove matching the contact protrusion on one side close to the air inlet cap; the contact protrusion, the contact groove and the orifice plate are all in the shape of regular polygons; The contact protrusion has a plurality of first convex surfaces, the edge of the orifice plate is provided with a second convex surface, and the contact groove is provided with a concave surface matching the first convex surface and the second convex surface; A first sealing ring is installed on the contact surface between the second air inlet section and the orifice plate; a second sealing ring corresponding to the first sealing ring is installed on the contact surface between the contact protrusion and the orifice plate, wherein one of the second sealing rings is sleeved on the first air outlet section; The air outlet cap and the air inlet cap are connected via a locking nut.

2. The rotary sonic nozzle for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The air outlet cap is connected to the orifice plate by screws. The screws include a screw rod and a nut connected to the screw rod. A blind hole matching the nut is provided on one side of the air inlet cap close to the air outlet cap.

3. The rotary sonic nozzle for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The first air outlet section includes a first sub-air outlet section and a second sub-air outlet section connected to the first sub-air outlet section, the first sub-air outlet section is located on a side away from the air outlet cap, and the second sub-air outlet section is located on a side close to the air outlet cap; the first sub-air outlet section is connected to the first air inlet section, and the first air inlet section and the second sub-air outlet section are not coaxial.

4. The rotary sonic nozzle for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The second air outlet section includes a first mixing tube section and a second mixing tube section connected to the first mixing tube section. The first mixing tube section is located close to the second air inlet section, and the second mixing tube section is located away from the second air inlet section. Multiple second air inlet sections are all connected to the first mixing tube section.

5. The rotary sonic nozzle for a coaxial cylindrical deflagration drive device according to claim 1, characterized in that: The contact protrusion is provided with a first groove corresponding to the second sealing ring, and the contact groove is provided with a second groove surrounding the second air inlet section; The second sealing ring on the contact surface between the contact protrusion and the orifice plate is located in the first groove, and the first sealing ring on the contact surface between the second air inlet section and the orifice plate is located in the second groove.

6. The rotary sonic nozzle for a coaxial cylindrical deflagration drive device according to any one of claims 1 to 5, characterized in that: Along the first direction, the thickness of the orifice plate is 300 μm-500 μm.

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