Explosive wave simulation shock tube side wall sparse wave elimination device and design method thereof

Abstract

The invention relates to an explosive wave simulation shock tube auxiliary device and a design method thereof, aims to solve the problem that an existing explosive wave simulation shock tube orifice sparse wave eliminating device cannot be suitable for a high-pressure working condition due to the fact that the structure of the device occupies a certain tube orifice space, and further weakens the influence of shock waves on the safety outside a tube orifice. The explosive wave simulation shock tube side wall sparse wave eliminating device and the design method thereof are provided. The device comprises a plurality of annular cylinders which are sequentially connected in the axial direction, and two arc-shaped cover plates which are attached to the outer side wall of each cylinder, are oppositely arranged and can move in the circumferential direction. Sliding rails used for circumferential movement of the cover plate are arranged between every two adjacent barrel bodies and at the ends of the two barrel bodies located on the outermost side. And a plurality of wave absorbing holes are formed in the side wall of each cylinder body. The invention further provides a design method of the device for eliminating the sparse waves on the side wall of the blast wave simulation shock tube.

Description

Technical Field

[0001] The present invention relates to an explosion wave simulation shock tube auxiliary device and a design method thereof, and particularly to a sidewall rarefaction wave elimination device for an explosion wave simulation shock tube and a design method thereof. Background Art

[0002] An explosion wave simulation shock tube is an important test platform for simulating explosion shock waves, and is widely used in many fields such as the evaluation of the anti-explosion shock performance of bridges, buildings, vehicles, and the research on biological blast injuries. The peak pressure and positive pressure action time of the shock wave generated by it are the key indicators for evaluating the simulation effect.

[0003] For a shock tube used to simulate the explosion wave action environment, the overpressure of the shock wave generated therein will decay with time. When the shock wave overpressure decays to a certain value or below, the post-shock wave airflow changes from supersonic to subsonic. At this time, a rarefaction wave that propagates reversely into the shock tube pipeline will be generated after the shock wave passes through the shock tube nozzle. During the experiment, the rarefaction wave will destroy the flow field environment in the expansion section of the shock tube, affect the shock wave pressure history in the test section, and lead to inaccurate experimental data.

[0004] When conducting experiments related to explosion wave simulation shock tubes, in order to avoid a rapid drop in overpressure and an abnormal increase in dynamic pressure in the pipeline (especially the flow field environment at the test section where the effect object to be evaluated is placed), experimental personnel usually install a rarefaction wave elimination device with an adjustable discharge area (usually a nozzle rarefaction wave elimination device) at the nozzle to achieve rarefaction wave elimination.

[0005] However, the disadvantages of using only a nozzle rarefaction wave elimination device are as follows: First, since the jet will contract when the subsonic airflow flows out of the pipeline, in the working condition with a relatively large overpressure, in order to accurately eliminate the rarefaction wave at the nozzle, the discharge area ratio of the rarefaction wave elimination device needs to be greater than 100%, which cannot be achieved by relying solely on the nozzle rarefaction wave elimination device; Second, the flow velocity increases after the airflow passes through the rarefaction wave elimination device, which will affect the external safety of the nozzle. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem that the existing nozzle rarefaction wave elimination device for an explosion wave simulation shock tube cannot be applied to higher pressure working conditions due to its own structure occupying a certain nozzle space, and at the same time further weaken the impact of the shock wave on the external safety of the nozzle, and provide a sidewall rarefaction wave elimination device for an explosion wave simulation shock tube and a design method thereof.

[0007] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0008] A sidewall rarefaction wave elimination device for an explosion wave simulation shock tube, characterized in that:

[0009] It includes several circular cylinders connected in sequence along the axial direction at the outlet end of the low-pressure section of the blast wave simulation shock tube, and two oppositely arranged arc-shaped covers that are arranged on the outer side walls of each cylinder and can move circumferentially.

[0010] Sliding rails for the circumferential movement of the corresponding covers are arranged between adjacent two of the cylinders and at the ends of the two outermost cylinders.

[0011] A plurality of wave-dissipating holes are arranged on the side walls of each cylinder.

[0012] The cover is used to adjust the total discharge area of the wave-dissipating holes by covering or exposing the wave-dissipating holes through circumferential movement.

[0013] Further, the shape of each of the wave-dissipating holes is rectangular, and the plurality of wave-dissipating holes on each cylinder are divided into two groups. The two groups of wave-dissipating holes are respectively located on both sides of the cylinder in the horizontal direction and are arranged in central symmetry about the axis of the cylinder.

[0014] Further, the direction along the circumference of the cylinder is defined as a column. The shape of each group of the wave-dissipating holes on each cylinder includes a short rectangle and a long rectangle, and the wave-dissipating holes of the two shapes are arranged in a staggered manner in columns; the shapes of the wave-dissipating holes in the same column are the same, and the length direction of the wave-dissipating holes is arranged along the circumferential direction; the total discharge area of the wave-dissipating holes on each cylinder is inversely proportional to the distance between the cylinder and the outlet end of the blast wave simulation shock tube.

[0015] Further, the number of the cylinders is five; one end of the outermost cylinder is connected to the outlet end of the blast wave simulation shock tube through an adapter flange.

[0016] Further, the number of short-rectangle wave-dissipating holes in each group of the wave-dissipating holes on each cylinder is three columns, with five in each column; the number of long-rectangle wave-dissipating holes is two columns, with four in each column.

[0017] Meanwhile, the present invention also provides a design method for the side-wall rarefaction wave elimination device of the above blast wave simulation shock tube, which is characterized in that it includes the following steps:

[0018] Step 1: Prepare a blast wave simulation shock tube equipped with a nozzle rarefaction wave elimination device, install a first pipe with side-wall openings between the main body end of the blast wave simulation shock tube and the nozzle rarefaction wave elimination device. The inner diameter of the first pipe is the same as the inner diameter of the blast wave simulation shock tube, measure the cross-sectional area A of the blast wave simulation shock tube pipeline c and the discharge area A of the opening at the end of the first pipe e , and calculate the Mach number M2 of the post-shock air flow flowing through the blast wave simulation shock tube and the outflow Mach number M of the shock wave when it flows out of the side wall of the first pipe according to the magnitude of the maximum static pressure p2 of the post-shock air flow that can be generated in the shock tube used and the atmospheric environmental pressure p1 of the experimental site j, and the actual total outflow area S of the opening on the side wall of the first pipeline and the shock wave at the end of the first pipeline j ;

[0019] Step 2: Calculate the cosine value cosα of the angle α between the jet direction of the shock wave ejected from the side wall of the first pipeline and the central axis of the first pipeline according to the Mach number M2 of the post-shock air flow passing through the shock tube of the explosion wave simulation and the outflow Mach number M j when the shock wave flows out of the side wall of the first pipeline jj of the shock wave jj and the shock wave jet contraction coefficient C s ;

[0020] Step 3: Calculate the size of the opening area S of the side wall of the first pipeline according to the actual total outflow area S j of the opening on the side wall of the first pipeline and the shock wave at the end of the first pipeline, the discharge area A e of the opening at the end of the first pipeline, the shock wave jet contraction coefficient C s , and the sine value sinα jj of the angle α between the jet direction of the shock wave ejected from the side wall of the first pipeline and the central axis of the first pipeline jj ; e

[0021] Step 4: Set the opening on the side wall of the first pipeline as n cylinders, and let S e = S1 + S2 + S3 +... + S n , where S1, S2, S3... S n are the total areas of the shock wave elimination holes on each cylinder of the actual shock wave simulation shock tube side wall rarefaction wave elimination device, and n is a positive integer greater than or equal to 1;

[0022] Step 5: Allocate the areas and positions of multiple shock wave elimination holes according to the actual experimental conditions to form a shock wave simulation shock tube side wall rarefaction wave elimination device;

[0023] Step 6: Establish a shock wave simulation shock tube model in the simulation software, and under the condition of the static pressure p2 of the post-shock air flow of the maximum shock wave, conduct a simulation test on the shock wave simulation shock tube side wall rarefaction wave elimination device obtained in Step 5. If the elimination of the rarefaction wave reaches the expected effect, the design of the shock wave simulation shock tube side wall rarefaction wave elimination device is completed; if the expected effect is not achieved, return to Step 5 and re-allocate the areas and / or positions of the n shock wave elimination holes.

[0024] Furthermore, in Step 1, the calculation formula for the Mach number M2 of the post-shock air flow passing through the shock tube of the explosion wave simulation is as follows:

[0025]

[0026] Among them, γ is the specific heat ratio of the shock wave simulating the external ambient atmosphere of the shock tube;

[0027] The actual total outflow area S of the openings on the side wall of the first pipeline and the shock wave at the end of the first pipeline j The calculation formula is as follows:

[0028]

[0029] Among them, M j is the outflow Mach number when the shock wave flows out of the side wall of the first pipeline. When M j = 1; when When Among them

[0030] Furthermore, in step 2, the cosine value cosα of the angle α between the jet direction of the shock wave shooting out from the side wall of the first pipeline and the central axis of the first pipeline jj The calculation formula is as follows: jj The calculation formula is as follows:

[0031]

[0032] Among them α = (γ + 1) / (γ - 1).

[0033] Furthermore, in step 2, the jet contraction coefficient C of the shock wave s The calculation formula is as follows:

[0034]

[0035] Among them

[0036] A = (2m - 1)(1 - C0), B = 2(1 - m)(1 - C0);

[0037] Furthermore, in step 3, the opening area S of the side wall of the first pipeline e The calculation formula is as follows:

[0038]

[0039] Among them

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] 1. The shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention can effectively shunt the post-shock air flow passing through the end of the shock wave simulation shock tube, thereby greatly reducing the static pressure and flow velocity of the air flow outside the shock tube nozzle, providing a strong guarantee for the overall safety of shock tube tests.

[0042] 2. The shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention can further increase the total discharge area of the rarefaction wave elimination system, improve the upper limit of the shock wave pressure adapted by the rarefaction wave elimination system, and can further reduce the static pressure and velocity of the outflow in the nozzle axis direction by shunting the outflow of the rarefaction wave elimination device.

[0043] 3. For the shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention, the wave elimination holes of the sidewall type rarefaction wave elimination device adopt a design scheme of symmetric distribution on both horizontal sides of the tube body. To avoid ground reflection waves, no orifices are provided below the tube body. Correspondingly, to avoid unnecessary interference factors introduced by asymmetric outflow in the wave elimination section, no orifices are provided above the tube body either. This minimizes various external interference factors.

[0044] 4. The shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention can dynamically adjust its own discharge area and can be effectively applied to shock waves with pressure decaying over time. At the same time, the elimination device adopts a design scheme of staggered arrangement of rectangular openings with different shapes, which can effectively avoid stress concentration, reduce the thickness and material requirements of the pipeline design, and is conducive to cost reduction.

[0045] 5. The shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention can dynamically arrange the number and opening area of the wave elimination holes during design, thereby dynamically adjusting its own discharge area and can be effectively applied to shock waves with pressure decaying over time.

[0046] 6. The design method of the shock wave simulation shock tube sidewall rarefaction wave elimination device provided by the present invention has accurate results and simple steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic diagram of the principle of the embodiment of the design method of the shock wave simulation shock tube sidewall rarefaction wave elimination device of the present invention;

[0048] Figure 2 is a schematic structural diagram of the embodiment of the shock wave simulation shock tube sidewall rarefaction wave elimination device of the present invention;

[0049] Figure 3 is a schematic structural diagram of the cylinder body in the embodiment of the shock wave simulation shock tube sidewall rarefaction wave elimination device of the present invention;

[0050] Figure 4This is the front view of the embodiment of the device for eliminating rarefaction waves on the side wall of the shock tube for simulating explosion waves according to the present invention;

[0051] Figure 5 This is the structural schematic diagram of the combination of the embodiment of the device for eliminating rarefaction waves on the side wall of the shock tube for simulating explosion waves according to the present invention and the device for eliminating rarefaction waves at the tube orifice;

[0052] Figure 6 This is the structural schematic diagram of the device for eliminating rarefaction waves at the tube orifice used in cooperation with the embodiment of the present invention;

[0053] Explanation of reference numerals:

[0054] 1 - wave - eliminating hole; 2 - cover plate; 3 - slide rail; 4 - adapter flange; 5 - cylinder body, 6 - device for eliminating rarefaction waves on the side wall, 7 - device for eliminating rarefaction waves at the tube orifice, 71 - frame, 711 - frame adapter flange, 712 - partition board; 721 - fan blade, 722 - fan blade rotating shaft, 73 - gear, 74 - transition section, 741 - tube orifice adapter flange, 742 - transition section cylinder body, 743 - transition section adapter flange. Detailed implementation manners

[0055] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0056] A device for eliminating rarefaction waves on the side wall of a shock tube for simulating explosion waves, see Figures 2 to 4 , includes five circular cylinder bodies 5 connected in sequence along the axial direction, and two oppositely arranged arc - shaped cover plates 2 that are circumferentially movable and are attached to the outer side walls of each cylinder body 5; adapter flanges 4 are provided at the ends of the two outermost cylinder bodies 5, one of which is used to connect to the outlet end of the low - pressure section of the shock tube for simulating explosion waves, and slide rails for the circumferential movement of the cover plates are provided between adjacent two cylinder bodies 5 and at the ends of the two outermost cylinder bodies 5; a plurality of wave - eliminating holes are provided on the side walls of each cylinder body 5. Defining the circumferential direction of the cylinder body 5 as a column, the shape of each group of wave - eliminating holes 1 on each cylinder body 5 includes short rectangles and long rectangles, and the two - shaped wave - eliminating holes 1 are arranged in a staggered manner in columns, and the shapes of the wave - eliminating holes 1 in the same column are the same. Among them, the number of short - rectangle wave - eliminating holes 1 in each group of wave - eliminating holes 1 on each cylinder body 5 is three columns, with five in each column; the number of long - rectangle wave - eliminating holes 1 is two columns, with four in each column.

[0057] Particularly, the two groups of wave - eliminating holes 1 are symmetrically arranged about a radial symmetry axis of the cylinder body 5.

[0058] Meanwhile, the present embodiment also provides a design method for the above - mentioned device for eliminating rarefaction waves on the side wall of the shock tube for simulating explosion waves, see Figure 1 , including the following steps:

[0059] Step 1: Prepare a shock wave simulation shock tube equipped with a nozzle rarefaction wave elimination device. Install a first pipe with side wall openings between the end of its main body and the nozzle rarefaction wave elimination device. The inner diameter of the first pipe is the same as that of the shock wave simulation shock tube, and measure the cross-sectional area A of the shock wave simulation shock tube c and the discharge area A of the opening at the end of the first pipe e , and calculate the Mach number M2 of the post-shock air flow flowing through the shock wave simulation shock tube, the outflow Mach number M j when the shock wave flows out of the side wall of the first pipe, and the actual total outflow area S of the shock wave at the side wall openings of the first pipe and the end of the first pipe j ;

[0060]

[0061] where M j is the outflow Mach number when the shock wave flows out of the side wall of the first pipe. When , M j = 1; when , where

[0062] Step 2: According to the Mach number M2 of the post-shock air flow flowing through the shock wave simulation shock tube, the outflow Mach number M j when the shock wave flows out of the side wall of the first pipe, and the specific heat ratio γ of the external ambient atmosphere of the shock wave simulation shock tube, calculate the cosine value cosα jj of the angle α between the jet direction of the shock wave ejected from the side wall of the first pipe and the central axis of the first pipe jj and the shock wave jet contraction coefficient C s ;

[0063]

[0064] where

[0065]

[0066] where A = (2m - 1)(1 - C0), B = 2(1 - m)(1 - C0);

[0067] Step 3: According to the actual total outflow area S j of the shock wave at the side wall openings of the first pipe and the end of the first pipe, the discharge area A e of the opening at the end of the first pipe, and the shock wave jet contraction coefficient C s, the sine value sinα of the included angle α between the jet direction in which the shock wave shoots out from the side wall of the first pipeline and the central axis of the first pipeline jj , calculate the opening area S of the side wall of the first pipeline jj ; e Magnitude;

[0068]

[0069] Among them, sinα jj = 1 - cos 2 α jj ;

[0070] Step 4. Let S e = S1 + S2 + S3 +... + S n , where S1, S2, S3... S n is the area of each wave elimination hole 1 on each cylinder body 5 of the actual explosion wave simulation shock tube side wall rarefaction wave elimination device. There are n wave elimination holes 1 in total, and n is a positive integer greater than or equal to 1;

[0071] Step 5. According to the actual experimental conditions, allocate the areas and positions of the n wave elimination holes to form an explosion wave simulation shock tube side wall rarefaction wave elimination device;

[0072] Step 6. Establish an explosion wave simulation shock tube model in the simulation software. Under the condition of the static pressure p2 of the airflow after the maximum shock wave, conduct a simulation test on the explosion wave simulation shock tube side wall rarefaction wave elimination device obtained in Step 5. If the elimination of the rarefaction wave reaches the expected effect, the design of the explosion wave simulation shock tube side wall rarefaction wave elimination device is completed; if the expected effect is not achieved, return to Step 5 and re-allocate the areas and / or positions of the n wave elimination holes.

[0073] Particularly, in actual use, before each experiment, use the static pressure p of the airflow after the shock wave generated in the shock tube according to the experimental plan of this experiment to replace the static pressure p2 in Step 1, and repeat the calculation process of Steps 1 to 3 to obtain the total opening area S required for the side wall type rarefaction wave elimination device in this experiment. By sliding the cover plate 2 on each cylinder body 5 to adjust the total area of the exposed elimination holes to S, the elimination of the rarefaction wave can be realized in the experiment.

[0074] As Figure 5 shown, the side wall rarefaction wave elimination device 6 provided in this embodiment can also be used in cooperation with the nozzle rarefaction wave elimination device 7. The side wall type rarefaction wave elimination device and the nozzle rarefaction wave elimination device 7 have a coupling effect, which can further increase the total discharge area of the rarefaction wave elimination system, and can further reduce the static pressure and velocity of the shock wave outflow in the axial direction of the explosion wave simulation shock tube nozzle by diverting the outflow flow rate of the rarefaction wave elimination device, thereby improving the accuracy of the experiment. For the specific structure of the nozzle rarefaction wave elimination device 7, refer toFigure 6 , including a rectangular frame 71, thirty fan blades 721 arranged on the frame 71, and two vertically arranged partition plates 712; the fan blades 721 are arranged in columns, and the number of fan blades 721 in each column is equal. Both sides of each fan blade 721 are provided with fan blade rotating shafts 722, and the fan blades 721 can rotate 360° driven by the fan blade rotating shafts 722. Each fan blade rotating shaft 722 is connected to a gear 73. Each fan blade 721 is arranged between two adjacent partition plates 712 or between a partition plate 712 and the inner side wall of the frame 71; the distance between two adjacent fan blades 721 in each column is equal; define the distance between two adjacent partition plates 712 as ω1, and the distance between the partition plate 712 on the side and the inner side wall of the frame 71 as ω2, ω1 = ω2; each gear 73 and fan blade rotating shaft 722 are used to control the rotation angle of the corresponding fan blade 721. The pipe orifice rarefaction wave elimination device 7 is connected to the adapter flange 4 at one end of the side wall rarefaction wave elimination device 6 away from the low-pressure section outlet end of the explosion wave simulation shock tube through a transition section 74; each gear 73 is connected to an external control mechanism. The transition section 74 includes a frame adapter flange 711 connected to the frame 71, a transition section adapter flange 743 connected to the frame adapter flange 711, a transition section cylinder 742 with one end connected to the transition section adapter flange 743, and a pipe orifice adapter flange 741 connected to the other end of the transition section cylinder 742. The pipe orifice adapter flange 741 is connected to the adapter flange 4 at one end of the explosion wave simulation shock tube away from the low-pressure section outlet end.

[0075] It should be noted that the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. An apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube, characterized in that: It includes a plurality of circular cylinders (5) connected in sequence along the axis at the outlet end of the low-pressure section of the explosion wave simulation shock tube, and two arc-shaped covers (2) arranged oppositely and circumferentially movable on the outer side walls of each cylinder (5); Sliding rails (3) for the circumferential movement of the corresponding covers (2) are provided between adjacent two of the cylinders (5) and at the ends of the two outermost cylinders (5); A plurality of wave-eliminating holes (1) are provided on the side walls of each cylinder (5); The cover (2) is used to adjust the total discharge area of the wave-eliminating holes (1) by covering or exposing the wave-eliminating holes (1) through circumferential movement.

2. The apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube according to claim 1, characterized in that: The shape of each of the wave-eliminating holes (1) is rectangular, and the plurality of wave-eliminating holes (1) on each cylinder (5) are divided into two groups. The two groups of wave-eliminating holes (1) are respectively located on both sides of the cylinder (5) in the horizontal direction and are centrosymmetrically arranged about the axis of the cylinder (5).

3. The apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube according to claim 2, characterized in that: Defining the circumferential direction along the cylinder (5) as a column, the shapes of each group of the wave-eliminating holes (1) on each cylinder (5) include short rectangles and long rectangles, and the wave-eliminating holes (1) of the two shapes are arranged staggeredly in columns; the shapes of the wave-eliminating holes (1) in the same column are the same, and the length direction of the wave-eliminating holes (1) is arranged circumferentially; the total discharge area of the wave-eliminating holes (1) on each cylinder (5) adjusted by the cover (2) is inversely proportional to the distance between the cylinder (5) and the outlet end of the explosion wave simulation shock tube.

4. The apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube according to claim 3, characterized in that: The number of the cylinders (5) is five; transfer flanges (4) are provided at the ends of the two outermost cylinders (5), and the transfer flanges (4) are used to connect with the outlet end of the explosion wave simulation shock tube or other external devices.

5. The apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube according to claim 4, characterized in that: The number of short rectangular wave-eliminating holes (1) in each group of the wave-eliminating holes (1) on each cylinder (5) is three columns, with five in each column; the number of long rectangular wave-eliminating holes (1) is two columns, with four in each column.

6. A design method for the blast wave simulation shock tube sidewall rarefaction wave elimination device according to any one of claims 1-5, characterized in that, It includes the following steps: Step 1: Prepare a shock wave simulation shock tube equipped with a nozzle rarefaction wave elimination device. Install a first pipe with side wall openings between the end of its main body and the nozzle rarefaction wave elimination device. The inner diameter of the first pipe is the same as that of the shock wave simulation shock tube, and measure the cross-sectional area A of the shock wave simulation shock tube c and the discharge area A of the opening at the end of the first pipe e , and calculate the Mach number M2 of the post-shock air flow flowing through the shock wave simulation shock tube, the outflow Mach number M of the shock wave when it flows out of the side wall of the first pipe, according to the maximum static pressure p2 of the post-shock air flow that can be generated in the shock tube used and the magnitude of the atmospheric pressure p1 in the experimental site j , as well as the actual total outflow area S of the shock wave at the side wall openings of the first pipe and the end of the first pipe j ; Step 2: According to the Mach number M2 of the airflow behind the shock wave flowing through the shock tube for the explosion wave simulation and the outflow Mach number M when the shock wave flows out of the side wall of the first pipeline, j calculate the cosine value cosα of the included angle α between the jet direction of the shock wave ejected from the side wall of the first pipeline and the central axis of the first pipeline jj and the jet contraction coefficient C of the shock wave jj ; s ; Step 3: Calculate the size of the opening area \(S\) of the first pipeline sidewall according to the actual outflow total area \(S\) of the opening on the sidewall of the first pipeline and the shock wave at the end of the first pipeline j , the discharge area \(A\) of the opening at the end of the first pipeline e , the shock wave jet contraction coefficient \(C\) s , the included angle \(\alpha\) between the jet direction of the shock wave ejected from the sidewall of the first pipeline and the central axis of the first pipeline jj and the sine value \(\sin\alpha\) of \(\alpha\) jj , and calculate the opening area \(S\) of the first pipeline sidewall e ; Step 4: Open n cylindrical bodies on the side wall of the first pipeline, and let S e = S1 + S2 + S3 +... + S n , where S1, S2, S3... S n is the total area of the wave elimination holes on each cylindrical body of the actual shock wave simulation shock tube side wall sparse wave elimination device, and n is a positive integer greater than or equal to 1; Step 5: Allocate the areas and positions of a plurality of wave-eliminating holes on each cylinder according to the actual experimental conditions to form an apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube; Step 6: Establish an explosion wave simulation shock tube model in a simulation software, and under the condition of the static pressure p2 of the air flow after the maximum shock wave, conduct a simulation test on the apparatus for eliminating rarefaction waves on the side wall of the explosion wave simulation shock tube obtained in Step 5. If the elimination of the rarefaction waves reaches the expected effect, the design of the apparatus for eliminating rarefaction waves on the side wall of the explosion wave simulation shock tube is completed; if the expected effect is not achieved, return to Step 5 and re-allocate the areas and / or positions of the wave-eliminating holes on the n cylinders.

7. The design method of the apparatus for eliminating rarefaction waves on the side wall of an explosion wave simulation shock tube according to claim 6, characterized in that: In Step 1, the calculation formula for the Mach number M2 of the airflow behind the shock wave flowing through the shock tube for explosion wave simulation is as follows: where γ is the specific heat ratio of the atmosphere in the external environment of the shock tube for explosion wave simulation; The actual total outflow area S of the opening on the side wall of the first pipeline and the shock wave at the end of the first pipeline j The calculation formula is as follows: Among them, M j is the outflow Mach number when the shock wave flows out of the side wall of the first pipeline. When , M j = 1; when , Among them 8. The design method of the rarefaction wave elimination device on the side wall of the shock tube for explosion wave simulation according to claim 7, characterized in that: In step 2, the cosine value cosα of the included angle α between the jet direction in which the shock wave shoots out from the side wall of the first pipe and the central axis of the first pipe jj is as follows jj The calculation formula is as follows: Among them α = (γ + 1) / (γ - 1).

9. The design method of the rarefaction wave elimination device on the side wall of the shock tube for explosion wave simulation according to claim 8, characterized in that: In step 2, the shock wave jet contraction coefficient C s is calculated according to the following formula: Among them A = (2m - 1)(1 - C0), B = 2(1 - m)(1 - C0); 10. The design method of the rarefaction wave elimination device on the side wall of the shock tube for explosion wave simulation according to claim 9, characterized in that: In step 3, the opening area S of the side wall of the first pipeline e is calculated as follows: Among them

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