A gas distribution method and a gas distribution system for a shock tube

Abstract

This invention relates to a shock tube gas distribution method and system. During shock tube experimental gas preparation, a gas distribution column and a mixing tank are used in conjunction to actively control the internal pressure of the gas distribution column. An additional pressure-reducing stage is added between the gas cylinder and the mixing cylinder. The gas distribution column buffers large fluctuations in gas flow and pressure, resulting in a more stable gas flow and significantly improving the accuracy of the experimental gas component ratio. Simultaneously, the mixing tank has only one inlet connecting to the gas distribution column and one outlet connecting to the shock tube, improving the tank's strength and pressure-bearing capacity, and enhancing gas distribution safety.

Description

Technical Field

[0001] This invention belongs to the field of shock tube technology, and particularly relates to a gas distribution method and gas distribution system for shock tubes. Background Technology

[0002] The shock tube is the core experimental device for generating a high-temperature and high-pressure transient environment. The shock tube is a long tube sealed at both ends, divided in the middle by a thin membrane into a high-pressure section (driving section) on the left and a low-pressure section (driven section / experimental section) on the right. The high-pressure section is filled with a high-pressure driving gas, and the low-pressure section is filled with an experimental gas. When the membrane is ruptured, the driving gas adiabatically compresses the experimental gas in a very short time, forming a shock wave that propagates to the right in the low-pressure section, and at the same time forming a rarefaction wave that propagates to the left on the left side of the membrane. When the shock wave and the rarefaction wave reach the two ends of the long tube respectively, they are reflected by the sealed tube ends. The reflected shock wave acts on the gas in the driven section again to achieve a secondary increase in temperature and pressure, and the reflected rarefaction wave causes the thermodynamic parameters of the high-pressure gas to decrease again.

[0003] A shock tube gas distribution system is a piping system that separately fills the driving section and the driven section of the shock tube with driving gas and experimental gas, respectively. Different gas distribution methods result in different piping systems. In existing technologies, some gas distribution systems directly supply gas to the shock tube, connecting various gas cylinders directly to the shock tube; others, such as the shock tube experimental apparatus disclosed in Chinese Patent CN119125425B, involve pre-mixing the gases from the oxidant and dilution cylinders through a pipeline into a mixing bottle, which then introduces the mixed experimental gas into the shock tube. In both methods, the pressure in the gas path output from each cylinder is relatively high, and even slight changes in the valve opening of each gas cylinder can cause significant fluctuations in the gas distribution flow rate. Whether the gas enters the shock tube directly or is transferred via a mixing bottle, it is affected by airflow fluctuations, making strict ratio control impossible and failing to achieve highly precise mixing of the experimental gases. This is particularly unsuitable for applications requiring high gas mixing accuracy, such as aerosol / liquid experiments. The second drawback of the existing technology is that the multiple air inlets on the shock tube or mixing tank severely weaken the structural strength of the shock tube or mixing tank, making its pressure-bearing capacity weaker and posing a safety hazard.

[0004] The shock wave and rarefaction wave inside the shock tube are reflected by the tube end. The reflected shock wave will undergo secondary reflection at the contact surface of high and low pressure gases, which affects the experimental section environment, greatly shortens the effective test time, and affects the measurement accuracy. It is difficult to meet the experimental requirements of reaction kinetics and long-term operating condition simulation of scramjet engines. Summary of the Invention

[0005] In view of the shortcomings or deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a gas distribution method and gas distribution system for a shock tube, which adds a stage of pressure reduction, reduces gas cylinder airflow fluctuations, and can accurately mix experimental gases; moreover, the mixing tank has fewer openings, so the structure is not weakened, thus solving safety hazards.

[0006] To solve the above-mentioned technical problems, the present invention has the following structure: The gas distribution method for the shock tube includes the process of sequentially injecting gas into the experimental section and the driving section of the shock tube. When injecting gas into the experimental section, different types of experimental gases are output from each gas cylinder, pass through a flow controller, and enter the gas distribution column for mixing. At this time, the gas distribution column outlet is closed. When the pressure inside the gas distribution column reaches the set value, the gas cylinder delivery line is closed, completing the gas distribution in the gas distribution column. Then, the gas distribution column outlet is opened, and the experimental gas enters the mixing tank. The gas distribution column repeatedly distributes gas and passes it into the mixing tank until the required pressure condition is reached in the mixing tank, at which point the gas distribution column outlet is closed. Finally, the mixing tank outlet is opened, and experimental gas is injected into the experimental section of the shock tube. When the required experimental pressure is reached, the mixing tank outlet is closed.

[0007] When injecting experimental gas into the shock tube experimental section from the mixing tank, the pressure change inside the mixing tank is monitored in real time. A throttle valve, a shut-off valve, and a safety valve are sequentially installed on the gas path at the outlet of the mixing tank. The gas injected into the drive section is divided into two paths: one is the drive gas, and the other is a heavy gas leading to the cap near the drive section of the shock tube. The drive gas is configured as follows: the acoustic impedance value of the experimental gas is calculated, and multiple gases are modulated to form the drive gas, making the acoustic impedance value of the drive gas equal to that of the experimental gas.

[0008] The shock tube's gas distribution system includes a gas source module, a driving gas distribution module, an experimental gas distribution module, and a central control module. The experimental gas distribution module includes a gas distribution column with multiple inlets and one outlet. The multiple inlets are connected to the experimental gas cylinders in the gas source module through corresponding gas distribution channels. Each gas distribution channel is equipped with a shut-off valve and a flow controller. The outlet of the gas distribution column is connected to the inlet of the mixing tank, with a shut-off valve in the middle. The outlet of the mixing tank is connected to the experimental section of the shock tube through gas distribution channel 2, with a shut-off valve on gas distribution channel 2. Pressure gauges are installed in the gas distribution column and the mixing tank.

[0009] Furthermore, a throttle valve is installed before the flow controller on the gas distribution channel.

[0010] The air distribution column is preferably a long cylindrical tube with multiple air inlets evenly distributed along its length and an air outlet located at one end of the tube.

[0011] Furthermore, starting from the outlet of the mixing tank, the second gas distribution channel is equipped with a throttle valve, a shut-off valve, and a safety valve in sequence.

[0012] Near the high-voltage section cap of the shock tube, a heavier gas with a density greater than the driving gas is injected from the gas source module. The driving gas is then mixed and prepared proportionally from the gas cylinder of the gas source module to ensure that the acoustic damping parameters of the driving gas are equal to those of the experimental gas.

[0013] Compared with the prior art, the advantages of the present invention are as follows: In the shock tube gas distribution method and system of the present invention, during the preparation of experimental gases, the gas distribution column and the mixing tank are used to actively control the internal pressure value of the gas distribution column. An additional pressure reduction stage is added between the gas cylinder and the mixing cylinder. The gas distribution column plays a role in buffering large fluctuations in gas flow and pressure, resulting in a more stable airflow. In addition, the flow controller can accurately control the gas flow of each gas path, which can significantly improve the proportion accuracy of experimental gas components and make the experimental gas in the gas distribution column more accurately configured. It is especially suitable for scenarios with high requirements for gas distribution accuracy, such as aerosol liquid experiments.

[0014] Another advantage is that only one inlet is opened on the mixing tank to connect to the gas distribution column and one outlet to connect to the shock pipe, instead of having multiple openings, which significantly improves the strength and pressure resistance of the mixing tank and enhances the safety of gas distribution.

[0015] This invention injects gas into the drive section in two paths: one is the drive gas, and the other is a heavy gas directed towards the high-pressure section cap of the shock tube. Utilizing the high molecular weight of the heavy gas, the propagation of rarefied waves to the left high-pressure section is slowed, preventing rapid attenuation of the flow field within the shock tube and significantly extending the effective experimental time. Furthermore, the acoustic impedance of the drive gas is equal to that of the experimental gas, ensuring that the contact surface between the drive and experimental gases remains stationary after shock wave reflection. This prevents secondary reflection of the reflected shock wave at the contact surface, further extending the effective experimental time for high-quality results.

[0016] During the preparation of experimental gases, a throttle valve, a shut-off valve, and a safety valve are sequentially installed on the gas line at the outlet of the mixing tank. The flow rate of the gas entering the shock tube is adjusted by the throttle valve according to the real-time monitored pressure inside the mixing tank to achieve uniform gas filling and eliminate the influence on sensitive gases. The safety valve can adjust the pressure entering the shock tube body to ensure that the pressure of the experimental gas entering the shock tube meets the requirements.

[0017] The gas distribution column is a long cylindrical tube with multiple air inlets evenly distributed along its length. The air outlet is located at one end of the tube. Gases entering the gas distribution column from different positions have a certain amount of time to mix as they flow along the length of the tube, which improves the mixing effect. The dispersed air inlets on the long cylindrical tube also prevent excessive weakening of the gas distribution column strength. Attached Figure Description

[0018] Figure 1 Flowchart of the gas mixing method of the present invention; Figure 2 : A schematic diagram of an embodiment of the gas distribution system of the present invention; The symbols in the diagram represent the following meanings: 1-Gas source module, 2-Driving gas preparation module, 3-Experimental gas preparation module, 31-Gas distribution channel one, 311-Shut-off valve one, 312-Throttle valve one, 313-Flow controller, 32-Gas distribution column, 32a-Inlet, 32b-Outlet, 33-Mixing tank, 33a-Inlet, 33b-Outlet, 34-Shut-off valve two, 35-Gas distribution channel two, 351-Throttle valve two, 352-Shut-off valve three, 353-Safety valve. Detailed Implementation

[0019] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0020] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only simplified descriptions for the convenience of describing this invention and do not mean that the indicated elements must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this invention.

[0021] The shock tube gas distribution method and system of this invention incorporate a gas distribution column during the gas injection process from various gas cylinders into the shock tube experimental section. The gas distribution column first collects the experimental gases of each component according to their proportions and pressures, then introduces them into a mixing tank with only one inlet and outlet. The mixing tank then charges the shock tube experimental section. The gas distribution column enables secondary pressure reduction and precise premixing during the gas distribution process, enhancing the pressure-bearing capacity of the mixing tank. Furthermore, the internal pressure of the mixing tank does not drop significantly during the charging process, ensuring uniform charging. Simultaneously, a heavy gas is introduced near the end of the shock tube driving section, forming a "light-heavy" gradient gas layer with the lighter driving gas. Utilizing the high molecular weight of the heavy gas, the propagation speed of the rarefied wave to the high-pressure section is slowed, preventing rapid attenuation of the flow field within the shock tube and extending the effective testing time of the shock tube.

[0022] The gas distribution method for a shock tube includes the process of sequentially injecting gas into the experimental section and the driving section of the shock tube. The gas distribution method of this invention is as follows: Figure 1 , Figure 2As shown, when injecting gas into the experimental section, different types of experimental gases are output from each gas cylinder, first undergo a pressure reduction (conventional setting), and then enter the gas distribution column 32 for mixing through the flow controller set in this invention. At this time, the gas outlet 32b of the gas distribution column 32 is closed. When the pressure inside the gas distribution column 32 reaches the set value, the gas cylinder delivery line is closed, completing the gas distribution in the gas distribution column 32. Then, the gas outlet 32b of the gas distribution column 32 is opened, and the experimental gas enters the mixing tank 33 for further mixing (at this time, the outlet 33b of the mixing tank 33 is closed). The gas distribution column 32 repeatedly distributes gas and introduces it into the mixing tank 33 until the required pressure condition is reached inside the mixing tank 33, at which point the gas outlet 32b of the gas distribution column 32 is closed. It is best to let the gas in the mixing tank 33 stand for a period of time, then open the outlet 33b of the mixing tank 33 to inject experimental gas into the shock tube experimental section. When the required experimental pressure is reached, the outlet 33b of the mixing tank 33 is closed, and the experimental gas preparation is completed.

[0023] The above-mentioned gas mixing method can actively control the pressure value in the gas mixing column, adding a pressure reduction stage between the gas cylinder and the mixing tank. The gas mixing column plays a role in buffering large fluctuations in gas flow and pressure, resulting in a more stable airflow. In addition, the flow controller 313 can accurately control the gas flow and pressure of each gas path, which can significantly improve the mixing accuracy of the experimental gas component ratio and make the experimental gas in the gas mixing column more accurately configured. It is especially suitable for scenarios with high requirements for gas mixing accuracy, such as aerosol liquid experiments.

[0024] Another advantage of the above scheme is that only one inlet is opened on the mixing tank to connect to the gas distribution column and one outlet to connect to the shock pipe, instead of having multiple openings, which significantly improves the strength and pressure bearing capacity of the mixing tank and enhances the safety of gas distribution.

[0025] In the above embodiment, a throttle valve, a shut-off valve (ball valve), and a safety valve 353 are sequentially installed on the gas path of the outlet 33b of the mixing tank 33. After the gas is mixed, a high-pressure and stable mixed gas system is formed inside the mixing tank 33. When gas is charged into the shock tube experimental section, the pressure change inside the mixing tank 33 is monitored in real time. If the pressure value inside the mixing tank 33 drops too quickly, it will affect the stability of the sensitive experimental gas. At this time, the flow area of ​​the throttle valve is reduced to reduce the flow rate, so as to achieve uniform gas charging and eliminate the influence of sudden pressure drop on the state of the sensitive gas. The safety valve 353 can regulate the pressure of the gas entering the shock tube to ensure that the pressure of the experimental gas entering the shock tube meets the requirements. Therefore, the above gas path at the outlet of the mixing tank can create experimental conditions that meet the requirements to the greatest extent.

[0026] After injecting the experimental gas into the shock tube experimental section, the driving section is then filled with gas. In this invention, the gas injected into the driving section is divided into two paths: one is the driving gas, and the other is a heavy gas that leads to the cap near the driving section of the shock tube. The heavy gas refers to a gas with a high molecular weight, such as carbon dioxide. The driving gas is generally a light gas, such as helium, hydrogen, or nitrogen. The density of the heavy gas is greater than that of the driving gas. By utilizing the high molecular weight characteristics of the heavy gas, the transmission of the rarefied wave to the high-pressure section on the left is delayed, and the rapid attenuation of the flow field inside the shock tube is avoided, which can significantly extend the effective experimental time of the shock tube.

[0027] The preferred method for configuring the driving gas is as follows: calculate the acoustic impedance value of the experimental gas, modulate the driving gas with multiple gases so that its acoustic impedance value is equal to that of the experimental gas, and keep the contact surface between the driving gas and the experimental gas stationary after the shock wave is reflected, so that the reflected shock wave has no secondary reflection at the contact surface, thereby further extending the effective experimental time with high quality.

[0028] This invention also discloses a shock tube gas distribution system, such as Figure 2 As shown, its principle is the same as the gas mixing method described above.

[0029] The gas distribution system of a shock tube typically includes a gas source module 1, a driving gas distribution module 2, an experimental gas distribution module 3, and a central control module. Embodiment 1 of the gas distribution system of this invention: The experimental gas distribution module 3 includes a distribution column 32, which has multiple inlets 32a and one outlet 32b. The multiple inlets 32a are respectively connected to each experimental gas cylinder in the gas source module 1 through corresponding distribution channels 31. The cylinder outlets are conventionally equipped with primary pressure reducing valves and pressure sensors. The distribution channels 31 are equipped with shut-off valves 311 and flow controllers 313. The shut-off valves 311 control the opening and closing of the distribution channels 31 and can also control the charging sequence of each gas component. The flow controllers... Device 313 adjusts the flow rate of each gas to control the proportion of each gas; the outlet 32b of the gas distribution column 32 is connected to the inlet 33a of the mixing tank 33, and a shut-off valve 34 is installed in the middle. The gas from all channels converges inside the gas distribution column 32 and enters the mixing tank 33 through a single outlet 32b. The shut-off valve 34 controls the opening and closing of the gas path between the gas distribution column 32 and the mixing tank 33, so that the gas distribution column 32 can fill the mixing tank 33 through multiple gas distributions; the outlet 33b of the mixing tank 33 is connected to the shock tube experimental section through the gas distribution channel 35. A shut-off valve 352 is installed on the gas distribution channel 35. The shut-off valve 352 controls the opening and closing of the gas distribution channel 35. When the shock tube experimental section reaches the pressure value, the gas filling is stopped in time. Pressure gauges are installed in the gas distribution column 32 and the mixing tank 33. The pressure gauges represent all devices that can detect pressure. The pressure of the gas distribution column 32 and the pressure of the mixing tank 33 are designed in advance according to the output pressure of the gas cylinder and the pressure required by the shock tube experimental section. The operation of each valve in the gas circuit is controlled according to the designed pressure value.

[0030] When this gas distribution system inputs experimental gas into the shock tube experimental section, first close the shut-off valve 2 34, then open each shut-off valve 1 311. When the pressure in the gas distribution column 32 reaches the set value, close the shut-off valve 1 311 to complete the gas distribution in the gas distribution column 32. Then open the shut-off valve 2 34 to input gas into the mixing tank 33. After repeated operations, the gas in the mixing tank 33 reaches the required pressure value. After standing for a period of time, open the shut-off valve 3 352 to charge the shock tube with experimental gas.

[0031] A shut-off valve is one option for controlling the opening and closing of the gas distribution channel; other valves that can perform the function of switching on and off are also within the scope of protection of this invention.

[0032] The flow controller 313 described above can be a mass flow controller, which can accurately measure and automatically adjust the output flow according to the environmental pressure and temperature, making it convenient and accurate.

[0033] The shut-off valve is preferably a ball valve.

[0034] The volume of the mixing tank 33 is designed according to experimental requirements, and it has built-in turbulent mixing blades. The rotation of the mixing blades makes the gas mixing more uniform. The mixing tank 33 adopts a high-pressure resistant structure formed by integral forging, which enhances the structural strength of the mixing tank. The inlet of the mixing tank 33 is sealed to the pipeline through a high-pressure flange, which enhances the sealing performance of the mixing tank.

[0035] The gas mixing system of this invention sets up a gas distribution column 32 and a gas mixing tank 33 between the experimental gas cylinder and the shock tube. The gas output from each gas cylinder first passes through the gas distribution column and then enters the gas mixing tank. The set pressure of the gas distribution column is between the gas cylinder outlet and the gas mixing tank. The pressure drop of the gas entering the gas distribution column is less than the pressure drop of the gas entering the gas mixing tank directly (that is, the gas distribution column plays a pressure reduction role). Therefore, the gas distribution column plays a role in buffering the airflow and pressure fluctuations. The gas entering the gas distribution column has less disturbance and it is easier to accurately control its flow rate and pressure. On this basis, the flow controller on each gas distribution channel precisely controls the gas flow rate and pressure, thereby significantly improving the accurate proportion of experimental gas components. In particular, it can meet the high-precision gas mixing requirements for aerosol liquid experiments.

[0036] In addition, the mixing tank 33 has only one inlet 33a and one outlet 33b, which significantly improves the strength and pressure bearing capacity of the mixing tank, meets the gas distribution requirements of supercritical high-pressure experiments, and enhances the safety of gas distribution.

[0037] Furthermore, a throttle valve 312 is installed before the flow controller 313 on the gas distribution channel 31. The throttle valve 312 can be a needle valve. By adjusting the opening of the throttle valve, the flow rate of the gas path can be finely adjusted, thereby finely adjusting the pressure to make the pressure of each gas path equal, which facilitates the control of the flow rate of each gas and further ensures the accurate proportion of experimental gases.

[0038] Example 2 The gas distribution column 32 is preferably a long cylindrical tube. Figure 2 Multiple air inlets 32a are evenly distributed along the length of the pipe, and air outlets 32b are located at one end of the pipe. The specific arrangement scheme is selected according to the number of air inlets 32a. When there are many inlets, it is considered to arrange them on both sides. Figure 2 As shown, eight air inlets are symmetrically arranged on both sides, but only four are used in this embodiment, with the other four closed and ready to be activated at any time; alternatively, they can be arranged at intervals on both sides. Gases entering the distribution column 32 from different positions along its length have a certain amount of time to mix as they flow along the length of the pipe, improving the mixing effect. The dispersed air inlets on the long column also prevent excessive weakening of the distribution column's strength. The distribution column 32 is integrally forged from a high-pressure resistant alloy, improving its structural strength and enhancing safety.

[0039] Example 3 Based on Embodiment 1, a pressure sensor is installed inside the mixing tank 33. From the outlet 33b of the mixing tank 33, the second gas distribution channel 35 is sequentially equipped with a second throttle valve 351, a third shut-off valve 352, and a safety valve 353. The second throttle valve 351 can be a needle valve. When a significant drop in pressure is detected inside the mixing tank 33, the throttle valve 351 is adjusted to reduce the flow rate, causing the pressure in the mixing tank 33 to rise. This eliminates the impact of rapid pressure changes on the sensitive experimental gas, achieving uniform gas filling. The safety valve 353 is used to control the pressure of the experimental gas entering the shock tube to meet the requirements. This embodiment maximizes the creation of experimental conditions that meet the requirements, achieving higher testing accuracy.

[0040] Example 4 In either Example 1 or Example 3, a heavy gas with a density greater than that of the driving gas is injected from the gas source module 1 near the high-pressure section cap of the shock tube. The high molecular weight of the heavy gas can delay the transmission of the rarefied wave to the left high-pressure section, avoid the rapid attenuation of the flow field inside the shock tube, and extend the effective experimental time of the shock tube.

[0041] Furthermore, a mixed driving gas is proportionally extracted from the gas cylinder of the gas source module 1 to make the acoustic damping parameters of the driving gas equal to the acoustic damping parameters of the experimental medium in the driven section. The experimental medium is usually a fuel cracking gas, air, or aerosol system.

[0042] The gas mixing system in the above embodiments also includes a central control module. The central control module is equipped with an acoustic damping matching algorithm and a gas mixing pressure regulation algorithm. It presets a gas ratio database corresponding to different experimental media and coordinates the control of each valve in the gas path to realize automatic control of the mixed gas ratio and the operation of the gas mixing system, ensuring the gas ratio accuracy and pressure stability.

[0043] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the invention do not depart from the spirit and scope of the invention and should be covered within the scope of the claims of the invention.

Claims

1. A gas distribution method for a shock tube, comprising the process of sequentially injecting gas into the experimental section and the driving section of the shock tube, characterized in that, When injecting gas into the experimental section, different types of experimental gases are output from each gas cylinder, pass through the flow controller (313), and enter the gas distribution column (32) for mixing. At this time, the outlet (32b) of the gas distribution column (32) is closed. When the pressure in the gas distribution column (32) reaches the set value, the gas cylinder delivery path is closed, and the gas distribution in the gas distribution column (32) is completed. Then, the outlet (32b) of the gas distribution column (32) is opened, and the experimental gas enters the mixing tank (33). The gas distribution column (32) repeatedly distributes gas and passes it into the mixing tank (33) until the required pressure condition is reached in the mixing tank (33). Then, the outlet (32b) of the gas distribution column (32) is closed. The outlet (33b) of the mixing tank (33) is opened, and the experimental gas is injected into the shock tube experimental section. When the required experimental pressure is reached, the outlet (33b) of the mixing tank (33) is closed.

2. The gas distribution method for the shock tube according to claim 1, characterized in that, When injecting experimental gas from the mixing tank (33) into the shock tube experimental section, the pressure change inside the mixing tank (33) is monitored in real time. A throttle valve, a shut-off valve and a safety valve (353) are sequentially installed on the gas path of the outlet (33b) of the mixing tank (33).

3. The gas distribution method for the shock tube according to claim 2, characterized in that, The gas injected into the drive section is divided into two paths: one is the drive gas, and the other is the heavy gas that goes to the cap of the drive section near the shock tube.

4. The gas distribution method for the shock tube according to claim 3, characterized in that, The method for preparing the driving gas is as follows: calculate the acoustic impedance value of the experimental gas, and modulate the driving gas with multiple gases so that the acoustic impedance value of the driving gas is equal to the acoustic impedance value of the experimental gas.

5. A shock tube gas distribution system, comprising a gas source module (1), a driving gas distribution module (2), an experimental gas distribution module (3), and a central control module, characterized in that, The experimental gas preparation module (3) includes a gas distribution column (32), which has multiple air inlets (32a) and an air outlet (32b). The multiple air inlets (32a) are respectively connected to each experimental gas cylinder in the gas source module (1) through each gas distribution channel (31). The gas distribution channel (31) is equipped with a shut-off valve (311) and a flow controller (313). The air outlet (32b) of the gas distribution column (32) is connected to the inlet (33a) of the mixing tank (33), and a shut-off valve (34) is set in the middle. The outlet (33b) of the mixing tank (33) is connected to the shock tube experimental section through a gas distribution channel (35). A shut-off valve (352) is set on the gas distribution channel (35). Pressure gauges are installed in the gas distribution column (32) and the mixing tank (33).

6. The gas distribution system for the shock tube according to claim 5, characterized in that, A throttle valve (312) is installed in front of the flow controller (313) on the gas distribution channel (31).

7. The gas distribution system for the shock tube according to claim 6, characterized in that, The air distribution column (32) is a long cylindrical tube with multiple air inlets (32a) evenly distributed along its length and an air outlet (32b) located at one end of the tube.

8. The gas distribution system for the shock tube according to claim 5 or 7, characterized in that, The gas distribution channel 2 (35) is provided with a throttle valve 2 (351), a shut-off valve 3 (352), and a safety valve (353) in sequence from the outlet (33b) of the mixing tank (33).

9. The gas distribution system for the shock tube according to claim 5, characterized in that, At the high-pressure section of the shock tube near the cap, a heavy gas with a density greater than that of the driving gas is injected from the gas source module (1).

10. The gas distribution system for the shock tube according to claim 9, characterized in that, The driving gas is mixed and configured according to a ratio from the gas cylinder of the gas source module (1) so that the acoustic damping parameter of the driving gas is equal to that of the experimental gas.

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