Multi-shock wave focusing ignition promotion experimental device and experimental method

Abstract

The invention relates to the technical field of shock wave experiments, and discloses a multi-shock wave focusing ignition promotion experiment device and method, the experiment device comprises a shock wave collision bin, the side wall of the bin body is provided with a plurality of connecting ports, and the connecting ports have different interval angles; the shock tube unit comprises two or more double-membrane shock tubes and gas distribution assemblies connected with the double-membrane shock tubes; the data acquisition unit comprises a photomultiplier, a plurality of pressure sensors, a constant current adapter electrically connected with the pressure sensors, and a data processing system electrically connected with the photomultiplier and the constant current adapter; compared with a traditional single-shock-wave single-set focusing ignition mode, multi-angle shock wave mutual coupling focusing ignition is utilized, the relation between shock waves of different incident angles and shock wave focusing is conveniently researched, the structure is simple, operability is good, repeatability is high, the ignition efficiency is greatly improved, and the blank of multi-shock-wave coupling ignition and experimental devices is filled up.

Description

Technical Field

[0001] The invention relates to the technical field of shock wave experiments, and in particular to a multi-shock wave focusing ignition promotion experimental device and an experimental method. Background Art

[0002] As new concept engines enter a hot stage, detonation engines will be used in the field of high-speed propulsion. However, when the aircraft is at a high flight speed, due to the limited length of the aircraft combustion chamber, the time that the air stays in the combustion chamber is also very limited, only in milliseconds or even microseconds. In milliseconds or even microseconds, how to achieve fast and reliable ignition of fuel becomes the main problem. For the detonation problem of detonation engines, researchers in the past have proposed many methods: direct detonation method, adding additives to enhance detonation to the fuel, pre-detonation tube method, using solid obstacles to convert deflagration to detonation, and using jets to convert deflagration to detonation. However, they all have corresponding shortcomings and are difficult to be applied in practice.

[0003] The most fatal disadvantage of direct detonation method is that it requires a large ignition energy. For some hydrocarbon fuels, the ignition energy is as high as several hundred kilojoules, and the energy provided by the spark plug is difficult to meet the ignition conditions. The biggest disadvantage of adding additives to enhance detonation in the fuel is that additional additive storage and supply devices are required, which greatly increases the burden on the system. The pre-detonation tube method uses the detonation wave formed in a small-sized pre-detonation tube to form a detonation wave in a large-sized main detonation chamber. Its main disadvantage is that it has poor stability. In some cases, the detonation wave in the pre-detonation tube may not be able to propagate stably, resulting in detonation failure.

[0004] In actual engineering and experimental research, the method of deflagration to detonation is usually used. Deflagration is a combustion wave that propagates at a subsonic speed, while detonation is an explosion wave that propagates at a supersonic speed in an unreacted medium. A detonation wave usually consists of a leading shock wave and a reaction zone that follows it, and can self-sustain and propagate with strong discontinuities. Using deflagration to detonation to obtain stable detonation is an important research direction to promote the development of detonation engines. There are two main ways to convert deflagration to detonation. One is to use solid obstacles such as baffle rings to induce detonation. The main disadvantage is that it will cause a drop in total pressure and a loss of power. The other is to use a transverse fluid jet to induce detonation, but it also requires the establishment of a special fluid storage device, which increases the complexity of the system and the burden on the system.

[0005] As people's understanding and research on the shock wave focusing phenomenon gradually deepens, using shock wave focusing to induce detonation has become a new hot research direction. Shock waves are compression waves in which the pressure, density and temperature in gas, liquid and solid media produce a sudden step change on the wave front, also called shock waves.

[0006] Existing research directions mainly focus on the shock wave focusing phenomenon generated by a single shock wave under different reflecting surface conditions, and lack the revelation of the shock wave focusing law and mechanism under double shock waves or even multiple shock waves coupling. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above-mentioned lack of experimental equipment for studying multi-shock wave focusing ignition promotion, the present invention is proposed.

[0009] Therefore, the purpose of the present invention is to provide a multi-shock wave focusing ignition promotion experimental device, which is to build an experimental device to reveal the shock wave focusing law and mechanism under double shock wave or even multi-shock wave coupling.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: a multi-shock wave focusing ignition promotion experimental device, which includes a shock wave collision chamber, a shock tube unit and a data acquisition unit, wherein the shock wave collision chamber has a plurality of connection ports on the side wall of the chamber body, and the connection ports have different spacing angles; the shock tube unit is connected to each of the connection ports, and includes no less than 2 double-membrane shock tubes and a gas distribution assembly connected to each of the double-membrane shock tubes; and the data acquisition unit includes a photomultiplier tube and a plurality of pressure sensors arranged in the side wall of the shock wave collision chamber, a constant current adapter electrically connected to each of the pressure sensors, and a data processing system electrically connected to the photomultiplier tube and the constant current adapter.

[0011] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, the aperture sizes of the connecting ports are the same, and the central axes of the connecting ports are in the same plane; the spacing angle between adjacent connecting ports is ~ degrees.

[0012] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device of the present invention, a pressure gauge is also provided in the side wall of the shock wave collision chamber, and the pressure gauge can monitor the pressure in the shock wave collision chamber.

[0013] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, the double-membrane shock tube includes a driving section, an intermediate section and a driven section connected in sequence, a first diaphragm is provided at the connection between the driving section and the intermediate section, and a second diaphragm is provided at the connection between the intermediate section and the driven section; one end of the driving section away from the intermediate section is blocked; and one end of the driven section away from the intermediate section is connected to the connecting port.

[0014] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, a first pressure gauge is arranged in the pipe wall of the driving section, a second pressure gauge and an exhaust pipeline are arranged in the pipe wall of the middle section, and an electromagnetic valve is arranged in the exhaust pipeline.

[0015] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, wherein: the gas distribution assembly includes a gas distribution panel, a first gas pipe, a second gas pipe and a third gas pipe; the first gas pipe is connected between the first gas port and the driving section of the gas distribution panel; the second gas pipe is connected between the second gas port and the middle section of the gas distribution panel; the third gas pipe is connected between the third gas port of the gas distribution panel and the shock wave collision chamber.

[0016] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, the gas distribution panel is also provided with a mixed fuel gas inlet, a high-pressure air inlet and a pump connection port; the pump connection port is connected to a vacuum pump.

[0017] As a preferred solution of the multi-shock wave focusing ignition promotion experimental device described in the present invention, wherein: each of the pressure sensors is respectively arranged in the side walls around the plane where each connection port in the shock wave collision chamber is located, and can monitor the pressure inside the shock wave collision chamber.

[0018] Another object of the present invention is to provide a multi-shock wave focusing ignition promotion experimental method, which is based on the above-mentioned experimental device, so as to reveal the laws and mechanisms of shock wave focusing under double shock waves or even multi-shock wave coupling.

[0019] In order to solve the above technical problems, the present invention provides the following technical solutions: a multi-shock wave focusing ignition promotion experimental method, based on the above multi-shock wave focusing ignition promotion experimental device, comprising the following operating steps: S1: Build the experimental device and initialize the state of the experimental device; S2: Operate the air distribution panel to evacuate the air in the driving section, the middle section and the shock wave collision chamber respectively through the vacuum pump, and after evacuation, close the air pipes connecting the driving section and the middle section with the air distribution panel; S3: Operate the gas distribution panel to fill the shock wave collision chamber with premixed gas through each gas pipe, and fill the driving section and the middle section with compressed air according to the preset shock wave intensity; S4: Open the solenoid valve in the exhaust line to release the pressure in the middle section. When the pressure difference between the drive section and the middle section is large enough, the first diaphragm and the second diaphragm rupture in sequence, and an incident shock wave is generated in the double-membrane shock tube and propagates toward the shock wave collision chamber. S5: Record the pressure signal and ignition time in the shock wave collision chamber after shock wave focusing, and use the data processing system to analyze the experimental data.

[0020] As a preferred solution of the multi-shock wave focusing ignition promotion experimental method described in the present invention, the pressure of the compressed air filled in the middle section is the average pressure of the driving section and the shock wave collision chamber.

[0021] Beneficial effects of the present invention: Compared with the traditional single shock wave single focusing ignition method, the present invention utilizes multi-angle shock waves to couple with each other for focusing ignition, which is not only convenient for studying the relationship between shock waves and shock wave focusing at different incident angles, but also has a simple structure, good operability, strong repeatability, and greatly improved ignition efficiency, thus filling the gap in multi-shock wave coupling ignition and experimental equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them: Figure 1 It is a schematic diagram of the overall structure of the multi-shock wave focusing ignition promotion experimental device of the present invention.

[0023] Figure 2 This is a schematic diagram of the three-dimensional structure of the connection between the shock wave collision chamber and the double-membrane shock wave tube of the multi-shock wave focusing ignition promotion experimental device of the present invention.

[0024] Figure 3 It is a schematic plan view of the internal structure of the shock wave collision chamber of the multi-shock wave focusing ignition promotion experimental device of the present invention.

[0025] Figure 4 This is a schematic diagram of the connection between the shock wave collision chamber and the shock wave tube unit of the multi-shock wave focusing ignition promotion experimental device of the present invention.

[0026] Figure 5 It is a schematic diagram of the operating system of the multi-shock wave focusing ignition promotion experimental device of the present invention.

[0027] The reference numerals in the figures are as follows: Shock wave collision chamber 100: connection port 101, pressure gauge 102; Shock tube unit 200: double-membrane shock tube 201, driving section 201a, first pressure gauge Y1, second pressure gauge Y2, exhaust pipeline P, solenoid valve F, middle section 201b, driven section 201c, first diaphragm 201d, second diaphragm 201e, gas distribution assembly 202, gas distribution panel 202a, first gas port 202a-1, second gas port 202a-2, third gas port 202a-3, mixed gas inlet 202a-4, high-pressure air inlet 202a-5, pump connection port 202a-6, first gas pipe 202b, second gas pipe 202c, third gas pipe 202d, vacuum pump 202e; Data acquisition unit 300: photomultiplier tube 301, pressure sensor 302, constant current adapter 303, data processing system 304. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0032] Example 1 Reference Figure 1~Figure 5, which is the first embodiment of the present invention, provides a multi-shock wave focusing ignition promotion experimental device, which includes a shock wave collision chamber 100, a shock tube unit 200 and a data acquisition unit 300, wherein the shock wave collision chamber 100 is used to provide a gathering and collision space for double shock waves or multiple shock waves; the shock tube unit 200 is used to generate the shock waves required for the experiment, is connected to the shock wave collision chamber 100, and allows the shock waves to enter the collision chamber; the data acquisition unit 300 is used to collect ignition data and pressure data in the shock wave collision focusing process, so as to facilitate the subsequent experimental analysis.

[0033] Specifically, the shock wave collision chamber 100 is of a regular shape as a whole, preferably a cubic structure, and a plurality of connection ports 101 are arranged on the side walls of the chamber body, and the connection ports 101 have different spacing angles; wherein the connection ports 101 connect the inside and the outside of the shock wave collision chamber 100; the aperture sizes of the connection ports 101 are the same, and the central axes of the connection ports 101 are all in the same plane; the spacing angles between adjacent connection ports 101 are between 0 and 180 degrees, so that the shock waves of various paths can converge and collide inside the shock wave collision chamber 100; it should be noted that the spacing angles of the connection ports 101 are preferably 60 degrees.

[0034] Furthermore, a pressure gauge 102 is provided in the side wall of the shock wave collision chamber 100 , and the pressure in the shock wave collision chamber 100 is monitored by the pressure gauge 102 .

[0035] The shock tube unit 200 is connected to each connection port 101 of the shock wave collision chamber 100, and includes at least two double-membrane shock tubes 201 and a gas distribution assembly 202 connected to each double-membrane shock tube 201; wherein the double-membrane shock tube 201 is a connecting pipe for generating shock waves; and the gas distribution assembly 202 is a gas distribution system for generating shock waves. In this scheme, two shock tubes of the same structure are used as an example for explanation.

[0036] Specifically, the double-membrane shock tube 201 is composed of a three-section rigid pipe, which is divided into a driving section 201a, an intermediate section 201b and a driven section 201c which are connected in sequence. A first diaphragm 201d is provided at the connection between the driving section 201a and the intermediate section 201b, and a second diaphragm 201e is provided at the connection between the intermediate section 201b and the driven section 201c; one end of the driving section 201a away from the intermediate section 201b is blocked; and one end of the driven section 201c away from the intermediate section 201b is connected to the connecting port 101.

[0037] Furthermore, the lengths of the driving section 201a and the middle section 201b can be changed, and the size of the middle section 201b is generally smaller; different from the existing shock tube, the feature of this solution does not lie in the ratio of the driving section 201a to the driven section 201c, but in whether shock waves incident at different angles and at the same speed can collide at the same point in the shock collision chamber 100.

[0038] It should also be noted that the connecting ends of each pipe section are connected by flanges, and grooves for accommodating rubber gaskets are provided on the flange surface, so that the double-membrane shock tube 201 has good air tightness.

[0039] Furthermore, a first pressure gauge Y1 is provided in the pipe wall of the driving section 201a, a second pressure gauge Y2 and an exhaust pipeline P are provided in the pipe wall of the middle section 201b, and an electromagnetic valve F is provided in the exhaust pipeline P. The first pressure gauge Y1 is used to observe the pressure in the driving section 201a, and the second pressure gauge Y2 is used to observe the pressure in the middle section 201b; the electromagnetic valve F is used to control the on-off of the exhaust pipeline P to achieve rapid discharge of gas in the middle section 201b.

[0040] The gas distribution assembly 202 includes a gas distribution panel 202a, a first gas pipe 202b, a second gas pipe 202c and a third gas pipe 202d; the first gas pipe 202b is connected between the first gas port 202a-1 of the gas distribution panel 202a and the driving section 201a; the second gas pipe 202c is connected between the second gas port 202a-2 of the gas distribution panel 202a and the middle section 201b; the third gas pipe 202d is connected between the third gas port 202a-3 of the gas distribution panel 202a and the shock wave collision chamber 100.

[0041] The gas distribution panel 202a is a control panel formed by the gas distribution system, and the existing gas distribution system can be used, and its specific structure is not described in detail. The first gas pipe 202b, the second gas pipe 202c and the third gas pipe 202d are all soft pipes for extracting and delivering gas, and are connected to the gas distribution panel 202a to realize gas control of the driving section 201a, the middle section 201b and the shock wave collision chamber 100.

[0042] The gas distribution panel 202a is also provided with a mixed gas inlet 202a-4, a high-pressure air inlet 202a-5 and a pump connection port 202a-6; the pump connection port 202a-6 is connected to a vacuum pump 202e. Among them, the mixed gas inlet 202a-4 is used to input premixed premixed gas; the high-pressure air inlet 202a-5 is used to input compressed high-pressure air. It should be noted that high-pressure air is selected as the driving gas because its main application scenario is high-speed aircraft; the vacuum pump 202e is used to extract the air in the double-membrane shock tube 201 and the shock collision chamber 100 and the combustion products after the experiment.

[0043] The data acquisition unit 300 includes a photomultiplier tube 301 and a plurality of pressure sensors 302 disposed in the side wall of the shock wave collision chamber 100 , a constant current adapter 303 electrically connected to each pressure sensor 302 , and a data processing system 304 electrically connected to the photomultiplier tube 301 and the constant current adapter 303 .

[0044] The photomultiplier tube 301 is installed in any side wall in the shock wave collision chamber 100 to monitor the ignition time at the moment of shock wave collision, and its accuracy is better than the traditional schlieren measurement method. Each pressure sensor 302 is respectively arranged in the side walls around the plane where each connection port 101 is located in the shock wave collision chamber 100, and can monitor the pressure inside the shock wave collision chamber 100; it should be noted that at least one pressure sensor 302 is installed on each side wall in the shock wave collision chamber 100, and the pressure distribution after the shock wave collision in the shock wave collision chamber 100 is obtained through the synchronous monitoring of each pressure sensor 302.

[0045] Each pressure sensor 302 is electrically connected to a constant current adapter 303, and is connected to a data processing system 304 through the constant current adapter 303. The constant current adapter 303 processes the experimental signal, reduces noise or performs gain, making it more obvious in the data acquisition system. When a shock wave passes through and produces a pressure change, the time of the change and the values ​​before and after the pressure change will be recorded by the data processing system 304.

[0046] Example 2 Reference Figure 5 , which is the second embodiment of the present invention, and provides a multi-shock wave focusing ignition promotion experimental method, based on the multi-shock wave focusing ignition promotion experimental device of the above embodiment 1, further comprising the following operating steps: S1: Build the experimental device and initialize the state of the experimental device; The experimental device is assembled according to its structure, and the connection integrity of the experimental device and the air tightness of the pipeline are tested to ensure that they are intact. The thickness of the first diaphragm 201d and the second diaphragm 201e is comprehensively determined by the type of passive experimental gas, the target five-zone temperature of the experiment, the target five-zone pressure, the initial temperature of the shock tube and the shock wave attenuation coefficient. The two diaphragms of appropriate thickness are installed between the driving section 201a and the middle section 201b.

[0047] S2: Operate the air distribution panel 202a to evacuate the air in the driving section 201a, the middle section 201b and the shock wave collision chamber 100 through the vacuum pump 202e, and then close the air pipes connecting the driving section 201a and the middle section 201b with the air distribution panel 202a; Specifically, by opening the gas distribution panel 202a, the air in each tube section of each double-membrane shock tube 201 and the shock collision chamber 100 is first evacuated using the vacuum pump 202e, and then the air pipes are closed to maintain a low-pressure pure environment in the experimental device.

[0048] S3: operate the gas distribution panel 202a to fill the premixed gas into the shock wave collision chamber 100 through the gas pipes, and fill the driving section 201a and the middle section 201b with compressed air according to the preset shock wave intensity; By controlling the gas distribution panel 202a, experimental gases are respectively injected into the shock wave collision chamber 100, the driving section 201a and the middle section 201b through various gas pipes, wherein premixed fuel gas is injected into the shock wave collision chamber 100, and compressed air is injected into the driving section 201a and the middle section 201b; it should be noted that the pressure of the compressed air is determined according to the required intensity of the shock wave.

[0049] Furthermore, the pressure of the compressed air filled in the middle section 201 b is the average of the pressures of the compressed air filled in the driving section 201 a and the shock wave collision chamber 100 .

[0050] S4: Open the solenoid valve F in the exhaust line P to release the pressure in the middle section 201b. When the pressure difference between the to-be-driven section 201a and the middle section 201b is large enough, the first diaphragm 201d and the second diaphragm 201e are ruptured in sequence, and an incident shock wave is generated in the double-membrane shock tube 201 and propagates toward the shock wave collision chamber 100. After filling the gas into each tube section of the double-membrane shock tube 201 and the shock collision chamber 100, close each connecting gas pipe; open the solenoid valve F to discharge the gas in the middle section 201b, and the middle section 201b is connected to the atmosphere to complete the pressure relief, then the pressure difference between the middle section 201b and the shock collision chamber 100 will increase; when the pressure difference is large enough, the first diaphragm 201d between the driving section 201a and the middle section 201b will rupture, and at the moment of rupture, the second diaphragm 201e between the middle section 201b and the driven section 201c will rupture, thereby generating an incident shock wave that propagates toward the shock collision chamber 100.

[0051] S5: Record the pressure signal and ignition time in the shock wave collision chamber 100 after the shock wave is focused, and use the data processing system 304 to perform experimental data analysis.

[0052] When the incident shock wave enters the shock wave collision chamber 100, the incident shock wave propagates toward the reflection surface, and the pressure sensor 302 installed on each wall is used to record the pressure signal after the shock wave is focused; using the collected pressure signal data, a pressure signal diagram of the shock wave reflection focusing can be obtained, and the subsequent wave system changes after the shock wave focusing can be observed. Finally, the experimental conclusion can be drawn based on the analysis of the experimental results.

[0053] Example 1 According to the experimental apparatus and experimental method in Examples 1 and 2, the experimental operation is carried out, which specifically includes the following process: S1: Build the experimental device and initialize the state of the experimental device; In the experimental device, the shock wave collision chamber 100 is made of stainless steel and quartz sheets, wherein the stainless steel forms a frame around the chamber, and the quartz sheets are located on two opposite sides and are transparent, so that the shock wave collision changes inside the chamber can be observed conveniently. Its shape and size are: length 0.31757m, width 0.15m, height 0.30938m. Multiple connection ports 101 are respectively opened on the side walls of the frame of the shock wave collision chamber 100, and the angles of the connection ports 101 are 30°, 90°, 120° and 180°.

[0054] Two double-membrane shock tubes 201 are provided with the same structure, which are respectively connected to two different connecting ports 101 on the shock collision chamber 100; the double-membrane shock tube 201 is made of stainless steel and is a circular pipe with a length of 1.2m and an inner diameter of 30mm, wherein the driving section 201a is 1m, the middle section 201b is 0.1m, and the driven section 201c is 0.1m; the connecting ends of each pipe section are connected by a special flange, and a groove with a diameter of 70mm and a depth of 4mm is provided on the disk surface of the flange, and a rubber gasket is installed in the groove.

[0055] In this example, the solenoid valve F is a solenoid valve of model BS22A produced by Shanghai Bangsong Company, with a nominal pressure of 5 MPa, a nominal diameter of 6 mm, a medium temperature of 90 K, and is powered by a 24 V DC power supply.

[0056] The first diaphragm 201d and the second diaphragm 201e are made of PET film, and the thickness thereof is determined by the type of driven experimental gas, the target five-zone temperature of the experiment, the target five-zone pressure, the initial temperature of the shock tube and the shock wave attenuation coefficient.

[0057] The data processing system 304 uses MR6000 from Japan Hioki Company, which has 8 channels and a sampling frequency of 200Msample / s. The data acquisition system obtains pressure signals through the BCN line and the constant current adapter. The data acquisition system is connected to the computer, and each experimental data can be automatically uploaded and saved in the computer.

[0058] For the driving gas and the driven gas, the driven gas selected in the experiment is hydrogen premixed fuel gas. In order to generate a shock wave with a pressure of 4 bar in the fifth zone and a temperature of 1200k in the fifth zone for the plane shock wave, the speed of the incident shock wave needs to be 817.6 m / s through the Caltech shock tube and detonation toolbox calculation. The shock wave collision chamber 100 is filled with 0.4357 bar of hydrogen premixed fuel gas, the driving section 201a is 8.7 bar of compressed air as the driving gas, and the middle section 201b is 4.5 bar of high-pressure air.

[0059] S2: Operate the gas distribution panel 202a to evacuate the air in the driving sections 201a and the middle section 201b of the two shock tubes and the shock collision chamber 100 through the vacuum pump 202e, and close the air pipes connecting the driving sections 201a and the middle section 201b with the gas distribution panel 202a after evacuation; S3: operate the gas distribution panel 202a again to fill the hydrogen premixed fuel gas into the shock wave collision chamber 100 through each gas pipe, and fill the driving section 201a and the middle section 201b with compressed air of the desired pressure according to the preset shock wave intensity; S4: Open the solenoid valve F in the exhaust line P to release the pressure in the middle section 201b. When the pressure difference between the to-be-driven section 201a and the middle section 201b is large enough, the first diaphragm 201d and the second diaphragm 201e are ruptured in sequence, and an incident shock wave is generated in the double-membrane shock tube 201 and propagates toward the shock wave collision chamber 100. S5: Record the pressure signal and ignition time in the shock wave collision chamber 100 after the shock wave is focused, and use the data processing system 304 to perform experimental data analysis.

[0060] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A multi-shock wave focusing ignition promotion experimental device, characterized in that: include, A shock wave collision chamber (100), wherein a plurality of connection ports (101) are arranged on a side wall of the chamber body, and the connection ports (101) have different spacing angles. A shock tube unit (200) connected to each of the connection ports (101), comprising no less than two double-membrane shock tubes (201) and a gas distribution assembly (202) connected to each of the double-membrane shock tubes (201); and, A data acquisition unit (300) comprises a photomultiplier tube (301) and a plurality of pressure sensors (302) arranged in the side wall of the shock wave collision chamber (100), a constant current adapter (303) electrically connected to each of the pressure sensors (302), and a data processing system (304) electrically connected to the photomultiplier tube (301) and the constant current adapter (303).

2. The multi-shock wave focusing ignition promotion experimental device according to claim 1, characterized in that: The apertures of the connection ports (101) are the same, and the central axes of the connection ports (101) are located in the same plane; The spacing angle between adjacent connection ports (101) is between 0 and 180 degrees.

3. The multi-shock wave focusing ignition promotion experimental device according to claim 2, characterized in that: A pressure gauge (102) is also provided in the side wall of the shock wave collision chamber (100), and the pressure gauge (102) is capable of monitoring the pressure in the shock wave collision chamber (100).

4. The multi-shock focusing ignition promotion experimental device according to claim 3 is characterized in that: The double-membrane shock tube (201) comprises a driving section (201a), an intermediate section (201b) and a driven section (201c) which are connected in sequence; a first diaphragm (201d) is provided at the connection between the driving section (201a) and the intermediate section (201b); and a second diaphragm (201e) is provided at the connection between the intermediate section (201b) and the driven section (201c); One end of the driving section (201a) away from the middle section (201b) is blocked; One end of the driven section (201c) away from the middle section (201b) is connected to the connection port (101).

5. The multi-shock focusing ignition promotion experimental device according to claim 4, characterized in that: A first pressure gauge (Y1) is arranged in the pipe wall of the driving section (201a), a second pressure gauge (Y2) and an exhaust pipeline (P) are arranged in the pipe wall of the middle section (201b), and a solenoid valve (F) is arranged in the exhaust pipeline (P).

6. The multi-shock wave focusing ignition promotion experimental device according to claim 5, characterized in that: The gas distribution assembly (202) comprises a gas distribution panel (202a), a first gas pipe (202b), a second gas pipe (202c) and a third gas pipe (202d); The first air pipe (202b) is connected between the first air port (202a-1) of the air distribution panel (202a) and the driving section (201a); the second air pipe (202c) is connected between the second air port (202a-2) of the air distribution panel (202a) and the middle section (201b); and the third air pipe (202d) is connected between the third air port (202a-3) of the air distribution panel (202a) and the shock wave collision chamber (100).

7. The multi-shock wave focusing ignition promotion experimental device according to claim 6, characterized in that: The gas distribution panel (202a) is also provided with a mixed gas inlet (202a-4), a high-pressure air inlet (202a-5) and a pump connection port (202a-6); The pump connection port (202a-6) is connected to a vacuum pump (202e).

8. The multi-shock wave focusing ignition promotion experimental device according to claim 7, characterized in that: Each of the pressure sensors (302) is respectively arranged in the side walls around the plane where each connection port (101) in the shock wave collision chamber (100) is located, and is capable of monitoring the pressure inside the shock wave collision chamber (100).

9. A multi-shock wave focusing ignition promotion experimental method, characterized in that: The multi-shock wave focusing ignition promotion experimental device as described in any one of claims 1 to 8 further comprises the following operating steps: Build the experimental device and initialize its status; Operating the air distribution panel (202a) to evacuate the air in the driving section (201a), the middle section (201b) and the shock wave collision chamber (100) respectively through a vacuum pump (202e), and after the air is evacuated, closing the air pipes connecting the driving section (201a) and the middle section (201b) with the air distribution panel (202a); Operating the gas distribution panel (202a) to fill the shock wave collision chamber (100) with premixed gas through the gas pipes, and filling the driving section (201a) and the middle section (201b) with compressed air according to the preset shock wave intensity; The solenoid valve (F) in the exhaust pipeline (P) is opened to release the pressure in the middle section (201b). When the pressure difference between the to-be-driven section (201a) and the middle section (201b) is large enough, the first diaphragm (201d) and the second diaphragm (201e) are ruptured in sequence, and an incident shock wave is generated in the double-membrane shock tube (201) and propagates toward the shock collision chamber (100); The pressure signal and ignition time in the shock wave collision chamber (100) after the shock wave is focused are recorded, and the experimental data analysis is performed using a data processing system (304).

10. The multi-shock focusing ignition promotion experimental method according to claim 9, characterized in that: The pressure of the compressed air filled in the middle section (201b) is the average of the pressures of the driving section (201a) and the shock wave collision chamber (100).

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