A shock wave overpressure measurement device and method based on Tesla valve flow channel

Abstract

The present invention discloses a shock wave overpressure measurement device and method based on a Tesla valve flow channel, the purpose of which is to solve the problems of difficult wiring, complex post-processing, and low precision of the existing measurement method. The measuring device of the present invention is generally in the form of a special-shaped rectangular parallelepiped, consisting of a cover plate and a base, and the cover plate is covered on the base. The base consists of a bottom plate, a sealing gasket strip and two limit guide rails. A Tesla valve-shaped flow channel is provided on the upper surface of the bottom plate, and a sealing gasket strip is pasted along the Tesla valve-shaped flow channel. The measurement method is to utilize the hindering effect of the Tesla valve on the fluid, so that the explosion shock wave continuously dissipates energy when propagating inside the Tesla valve, and decays into a measurable strong wind. By measuring the wind speed at the outlet of the Tesla valve, the inlet overpressure is reversed, and the explosion field shock wave overpressure is quickly measured. The present invention can realize the rapid quantitative measurement of the explosion field shock wave overpressure, and different measurement ranges can be realized by connecting multiple measuring devices in series. The measuring device has a simple structure, flexible layout, low cost, and can be reused.

Description

Technical Field

[0001] The present invention belongs to the field of measurement, and relates to a shock wave overpressure measuring device and a measuring method, and more specifically, to a shock wave overpressure measuring device and a measuring method based on a Tesla valve and an anemometer. Background Art

[0002] After the explosive explodes in the air, it will produce high-temperature, high-pressure and high-speed detonation products in a very short time. Its rapid outward expansion and work will squeeze the surrounding air medium to produce shock waves. The physical properties of the medium through which the shock wave passes will change stepwise, such as speed, pressure, temperature, and density. Since the explosion is a rapid energy release process, the various damage effects on the surrounding materials are relatively complex, mainly thermal damage and impact damage. The evaluation of the damage efficiency of the explosion shock wave is of great significance in terms of weapon research and development, the development of new explosives, and the demolition of specific structures. For the impact damage effect, the basic principle is that a large amount of high-temperature and high-pressure gas is produced by chemical reactions in a short period of time to do external work and then act on the external medium to form impact damage. At present, the research theory on shock waves is relatively sufficient. When the shock wave intensity is accurately mastered, the evaluation of shock damage can be predicted more accurately, but due to the complex explosion environment conditions, its measurement work is relatively difficult. Most of the current methods mainly evaluate the power of shock waves by measuring overpressure. This method has many inconveniences, mainly because the explosion field environment is relatively harsh, which is not conducive to the stable operation of the instrument. In an open environment, the relative size of the measurement sensor to the flow field is small and its impact can be ignored. However, within a small size range, the interference of the sensor itself on the flow field cannot be ignored.

[0003] At present, the methods for measuring the key parameters such as shock wave pressure and impulse generated by explosive explosion can basically be divided into two categories: active measurement methods and passive measurement methods. Active measurement methods mainly rely on various precision electrical sensors. Active measurement methods have developed to a relatively mature stage and dominate various current test practices. There is no shortage of high-precision and stable shock wave electrical measurement equipment on the market. However, in explosion test sites with complex terrain and harsh natural environments such as deserts, plateaus and islands, the layout of precision electronic measurement devices often faces many challenges, including but not limited to difficulties in installation and layout, high costs, and inability to effectively deploy due to geographical conditions. In such environments, traditional active measurement methods that rely on electrical sensors expose obvious limitations, especially under the strong electromagnetic interference generated at the moment of explosive explosion, which may cause the acquisition signal of the electrical measurement system to fail or the data quality to seriously deteriorate, manifested as signal disorder and reduced signal-to-noise ratio, which undoubtedly increases the difficulty of later data parsing and analysis. Therefore, it is particularly urgent and important to design a sensor that can realize passive detection of explosion shock wave parameters. This goal has become a key issue that technicians in this research field need to overcome.

[0004] In passive measurement technology, the methods for evaluating shock wave pressure parameters mainly include the Hopkinson bar method, the natural effect reference method, and the equivalent target plate method. However, when using the Hopkinson bar technology to measure the instantaneous pressure of the explosion shock wave, its system construction complexity is relatively high, which limits its practicality; while the natural effect method qualitatively judges the shock wave intensity range by observing physical phenomena such as pine board cracking, glass breaking, or small animal death. Although this method is intuitive, it is essentially a qualitative analysis and cannot meet the needs of large-scale and accurate evaluation of explosion damage effects. On the other hand, the equivalent target plate technology has certain feasibility in practical applications due to its advantages of rapid deployment, low cost, and no additional parasitic effects. It indirectly infers key parameters such as shock wave overpressure and specific impulse by measuring the deformation degree or damage state of the target plate after the explosion test. However, this method also has significant limitations. Under actual experimental conditions, the target plate may be insufficiently constrained, and factors such as rebound effect and collision will also affect the accuracy of the measurement results, resulting in a deviation between the actual measured deformation and the prediction under the ideal state. In addition, the target plate requires regular maintenance, and the post-processing steps of the experimental data are relatively cumbersome.

[0005] In summary, the existing measurement methods have at least the following technical problems:

[0006] 1. The currently popular electrical active sensing method still has many inconveniences in practical applications, such as prominent electromagnetic interference problems, high purchase and maintenance costs, and difficulty in wiring in complex and harsh natural environments, which makes it more difficult to accurately obtain shock wave parameters.

[0007] 2. Most current passive measurement methods are not ideal in terms of accuracy. Although there are some high-precision passive measurement solutions, they are also accompanied by many disadvantages. For example, these methods often require cumbersome and complex post-processing processes to analyze the data, and the measurement system itself has a high structural complexity, usually relying on additional electrical measurement auxiliary equipment for effective monitoring, or some structures need to be repeatedly replaced, such as target plates, which cannot effectively reduce the cost of use, thus limiting its convenience and practicality in field applications.

[0008] 3. The measurement range or applicable scope is small. When the proportional distance of the measurement point is large, some measuring devices may not respond or respond unstably when the shock wave arrives; when the proportional distance is small, the shock wave is strong and is likely to exceed the measurement range or even damage the measuring instrument. Existing passive measurement methods are difficult to achieve a large measurement range at a low cost.

[0009] In fact, among the many parameters describing shock waves, the velocity of the particle behind the wave is a physical quantity that can be measured without contact. When the shock wave propagates in the air, the air molecules can be considered as the particles behind the wave, so the wind speed can be considered as the velocity of the particle behind the wave. At present, the instruments for measuring velocity have high accuracy, and some measurement principles can achieve non-contact measurement.

[0010] In the patent US1329559 issued in 1920, Serbian-American scientist Nikola Tesla proposed a special structure conduit, namely the Tesla valve. The Tesla valve is a fluid valve used to control the flow direction of a steady fluid without any moving parts (such as valves, pistons or wheels). The principle of controlling the flow direction of the fluid is based on its special structure, which usually consists of a series of staggered elongated channels that are bent into a ring or spiral shape. When the fluid flows in one direction, due to the action of fluid momentum and friction, the fluid will bend along the channel and continue to flow; but when the fluid tries to flow in the opposite direction, due to the special design of the Tesla valve structure, the fluid will encounter greater resistance, thereby slowing down or stopping its flow. The advantage of the Tesla valve is that it has no moving parts, so it has a long life, low maintenance requirements and a small failure rate, and has a wide range of applications in liquid and gas control.

[0011] If we can start from the propagation characteristics of shock waves inside the Tesla valve and combine the attenuation law of shock waves in the Tesla valve, we can optimize the existing Tesla valve structure so that the shock wave speed can be quickly reduced to a strong wind speed that can be directly measured by an anemometer, and then use mature wind measuring instruments for measurement. It is expected that the shock wave intensity can be inferred through theoretical formulas combined with simulation results.

[0012] There is currently no public literature on the technical solution of combining a Tesla valve structure with an anemometer to measure shock wave overpressure. Summary of the invention

[0013] The technical problem to be solved by the present invention is to provide a shock wave overpressure measurement device and method based on the Tesla valve flow channel, which solves the problems of existing active shock wave measurement methods being susceptible to interference, high cost, difficult wiring in complex environments, and complex post-processing in practical applications; on the other hand, it solves the shortcomings of passive measurement methods such as unsatisfactory accuracy and difficulty in achieving low cost and large measurement range or wide application range at the same time. The measuring device of the present invention has a simple structure, low cost, strong anti-electromagnetic interference ability, and fast deployment. The measurement method results are easy to post-process, have high measurement accuracy, and a large measurement range. It can be used for quantitative measurement of shock wave overpressure under different geographical conditions, and at the same time provides a new reference option for shock wave parameter measurement.

[0014] The present invention utilizes the obstruction effect of the Tesla valve on the fluid, so that the explosion shock wave continuously dissipates energy when propagating inside the Tesla valve, and finally decays into a measurable strong wind. By measuring the wind speed at the outlet of the Tesla valve, the inlet overpressure is inferred, thereby realizing rapid quantitative measurement of the shock wave overpressure in the explosion field.

[0015] The measuring device of the present invention is generally in the form of a special-shaped rectangular parallelepiped, and is composed of a cover plate and a base, wherein the cover plate is covered on the base by bolts.

[0016] The cover plate is a rectangular parallelepiped with a length of L1, which is required to meet 0.1m<L1<0.9m, a width of W1, which is required to meet 0.05m<W1<0.5m, and a thickness of H1, which is required to meet 0.003m100MPa, density ρ1>1g / cm<h1> 3 The basic principle is that it does not deform under the action of shock waves, that is, it can be used as a solid wall.

[0017] The base is composed of a bottom plate, a circle of sealing gaskets and two limit rails, and the two limit rails are exactly the same in shape and structure. The limit rail is a long strip, welded on both sides of the long side of the bottom plate, so that the base appears U-shaped when viewed from the left end. The length of the bottom plate is L2, L2=L1, the width of the bottom plate is W2, satisfying 0.05m<W2<0.3m, and the overall height of the bottom plate is H2, which is required to satisfy 0.01m<H2<0.2m. The limit rails are welded on both sides of the upper surface of the base along the length direction to facilitate the installation of the cover plate between the two limit rails. The width of the limit rail W 24 The requirement is 0.001m<W 24 <0.05m, limit rail height H 24 Requirements to meet H 24>0.005m. A Tesla valve-shaped flow channel is provided on the upper surface of the bottom plate. The depth of the Tesla valve-shaped flow channel is d1, and it is required to satisfy d1<H2 and 0.01m<d1<0.02m. The width of the Tesla valve-shaped flow channel is d2, and it is required to satisfy d1=d2.

[0018] A circle of grooves is dug on the upper surface of both sides of the Tesla valve-shaped flow channel along the Tesla valve-shaped flow channel, and a circle of sealing gasket strips is pasted in the grooves. The width of the sealing gasket strips is W 20 The requirement is 0.001m<W 20 <0.02m, thickness of sealing gasket h 20 Requirements: 0.001m<h 20 <0.005m, the sealing gasket is just embedded in the groove, and the upper surface of the sealing gasket is flush with the upper surface of the bottom plate without the Tesla valve-shaped flow channel. The sealing gasket is made of high-strength pressure-resistant rubber, and the hardness grade is required to meet Sh≥60. It has a certain elasticity and can fit tightly with the upper surface of the bottom plate and the cover plate without air leakage. The Tesla valve-shaped flow channel is covered by the cover plate. Under the action of the sealing gasket and the cover plate, the upper surface of the Tesla valve-shaped flow channel is sealed, and the Tesla valve-shaped flow channel becomes a pipe with a square cross-section.

[0019] The Tesla valve-shaped flow channel is composed of an inlet, a first main flow channel, a first secondary flow channel, a first arc channel, a transition connection section, a second main flow channel, a second secondary flow channel, a second arc channel and an outlet. The central axis of the inlet coincides with the central axis of the outlet, and both are the central axis OO' of the Tesla valve-shaped flow channel, and OO' is consistent with the length direction of the bottom plate. The first main flow channel is connected to the inlet, and the angle is α, which is required to meet 50°>α>10°; the first main flow channel is connected to the first secondary flow channel, and the angle is β, which is required to meet β=2α; the first arc channel is connected to the first main flow channel and the first secondary flow channel; the transition connection section is connected to the first secondary flow channel and the second main flow channel and is in line, the second main flow channel is connected to the second secondary flow channel, the second arc channel is connected to the second main flow channel and the second secondary flow channel, and the outlet of the second secondary flow channel is connected, and the angle is α. The first arc channel and the second arc channel are circular arcs, with a central angle of 180° and a radius of R1, which is required to meet R1>0.01m.

[0020] There is a head protrusion on the bottom plate side facing left, and the length of the protrusion of the head protrusion is L 21 , it is required to meet 0.01m<L 21 <0.2m, head convex width is W 21 , requiring to satisfy W 21 <W1, the central axis of the head protrusion coincides with the central axis OO' of the Tesla valve-shaped flow channel. There is a tail groove on the right side of the bottom plate that is concave to the left, and the depth of the concave part is L 22 , requiring L 22 =L 21 , width W 22 , requiring W22 =W 21 The center axis of the tail groove coincides with the center axis OO' of the Tesla valve. The base is made of high-strength material, which is required to meet the following requirements: yield strength σ2>100MPa, density ρ2>1g / cm 3 The basic principle is that it does not deform under the impact of the shock wave, that is, it can be used as a solid wall to avoid changing the shape of the Tesla valve-shaped flow channel after the impact, thereby affecting the measurement accuracy. There are an even number of edge bolt holes and an even number of middle bolt holes on the bottom plate. The basic principle for selecting the positions of the edge bolt holes and the middle bolt holes is to ensure that the cover plate is firmly connected to the bottom plate while avoiding the overlap of the edge bolt holes and the middle bolt holes with the Tesla valve-shaped flow channel to affect the use effect.

[0021] The process of using the present invention to measure the explosion field shock wave is:

[0022] The first step is to calibrate the measuring device of the present invention using an existing free field pressure sensor (such as Kistler's 6233AA0250 free field pressure sensor, etc.), obtain a calibrated measuring device, and establish a conversion equation between outlet wind speed and inlet overpressure. The method is:

[0023] 1.1 Let the number of experiments n = 1, let the total number of experiments be N, N is a positive integer and N ≥ 8. Initialize the proportional distance k from the entrance to the explosion center n =2;

[0024] 1.2 Confirm whether the air tightness of the measuring device is good. Here is a simple method for reference: block the inlet and outlet with your fingers or other objects, then slowly immerse the measuring device in clean water to observe whether there are bubbles leaking out. If no obvious bubbles are seen, it means that the air tightness is good and the calibrated measuring device is obtained. Go to 1.3; if bubbles leak out, go to 1.8.

[0025] 1.3 Fix the measuring device and free-field pressure sensor to the corresponding position, and ensure that the proportional distance between the inlet and the explosion center and the proportional distance between the free-field pressure sensor and the explosion center are equal to k n At the same time, fix the anemometer probe so that it can work normally, that is, directly measure the outlet wind speed. The specific requirement is that the distance between the anemometer probe and the outlet is no more than 10mm. Adjust the measuring device so that the center OO' of the Tesla valve-shaped flow channel is aligned with the explosion center of the explosion field.

[0026] 1.4 at proportional distance k n Under this condition, measure the wind speed at the outlet and get k n The corresponding outlet wind speed v n , and a free-field pressure sensor is used to measure the shock wave overpressure p at this proportional distance nIf the outlet wind speed exceeds the anemometer range or there is no response, go to 1.5 to add another set of this device in series. If the outlet wind speed does not exceed the anemometer range, go to 1.6.

[0027] 1.5 Connect one set of this device in series. The method of series connection is:

[0028] 1.5.1 Prepare another set of measuring devices with the same specifications as the measuring device before series connection. The measuring device before series connection is No. ①, and the other set of measuring devices with the same specifications to be connected in series is No. ②.

[0029] 1.5.2 Insert the two long connecting pins on the right side of the base of No. ① measuring device into the two long connecting slots on the left side of the base of No. ② measuring device, and insert the two short connecting pins into the two short connecting slots on the left side of the base of No. ② measuring device.

[0030] 1.5.3 Place the cover plate of device No. 1 between the two limit guide rails and close to the sealing gasket strip on the upper surface of the bottom plate of device No. 1. At the same time, align the left plane of the cover plate of device No. 1 with the left plane of the protrusion of the head of device No. 1 to be coplanar. Use bolts to tighten the connection at the position where the bolt holes of the cover plate of device No. 1 and the bottom plate of device No. 1 overlap.

[0031] 1.5.4 Place the cover plate of device ② between the two limiting guide rails and close to the sealing strip on the upper surface of the bottom plate of device ②. At the same time, make the left plane of the cover plate of device ② close to the right plane of the cover plate of device ①. Use bolts to tighten the connection at the position where the bolt holes of the cover plate of device ② overlap with the bottom plates of devices ① and ②. The essence is to use the cover plate of device ② as a connector to achieve the effect of connecting and fixing the two bottom plates.

[0032] 1.5.5 Go to 1.1 and calibrate the measuring devices connected in series.

[0033] 1.6 At this time, we get k n The corresponding outlet wind speed v n , if n≤N, let n=n+1, let k n =(0.1n+0.9)k1, then turn to 1.3; if n>N, then turn to 1.7.

[0034] 1.7 N groups of data points consisting of the outlet wind speed and the inlet shock wave overpressure, namely (v1, p1), ..., (v n , p n ),…,(v N , p N ) is plotted in a rectangular coordinate system, and the distribution of the data points is observed. If the distribution of the data points is linear, a linear fit is performed, otherwise a high-order polynomial fit is performed to obtain the conversion equation between the outlet wind speed and the inlet overpressure of the measuring device of the present invention. Let the equation be p=f(v), p is the shock wave overpressure at the inlet 231, and v is the measured wind speed at the outlet, and then go to the second step.

[0035] 1.8 Solve the airtightness problem of the measuring device by checking whether the sealing strip is flat and not damaged, and whether the sealing strip fits tightly with the bottom plate. If there is any abnormality, replace it in time, and adjust the tightness of the connecting bolts to make the cover plate and the sealing strip fit tightly. After completion, go to 1.2.

[0036] The second step is to measure the shock wave overpressure using a calibrated measuring device, using the following method:

[0037] 2.1 Fix the calibrated measuring device to the position to be measured, and fix the anemometer measuring probe so that it can work normally, that is, directly measure the outlet wind speed. The specific requirement is that the distance between the anemometer measuring probe and the outlet is no more than 10mm. Align the central axis OO' of the measuring device entrance with the explosion center, or adjust it to ensure that the central axis OO' is perpendicular to the plane wave front of the shock wave to be measured.

[0038] 2.2 Create an explosion shock wave by detonating explosives or other means. The shock wave is transmitted to the measuring device. At this time, the inlet receives the shock wave and transmits it into the first main channel. The first secondary channel diverts part of the shock wave in the first main channel. The first arc channel receives the shock wave transmitted from the first main channel and guides the shock wave into the connection between the first secondary channel and the transition connection section, so that the shock wave converges and reflects with the shock wave in the first secondary channel at this connection. Part of the shock wave is reflected to the left into the first secondary channel, and part of the shock wave is reflected upward back into the first arc channel. These two parts of the shock wave are constantly reflected on the inner wall of the connection between the first secondary channel and the transition connection section, and several vortices will be formed, which will eventually disappear due to the continuous dissipation of energy. The remaining shock waves after convergence and reflection flow to the right through the transition connection section and propagate to the second main channel.

[0039] 2.3 Similarly, the second secondary flow channel diverts a part of the shock wave front in the second main flow channel, and the second arc channel receives the shock wave propagated from the second main flow channel and guides the shock wave into the connection between the second secondary flow channel and the second arc channel, so that the shock wave front converges and reflects with the shock wave in the second secondary flow channel at the connection. Part of the shock wave front is reflected to the left into the second secondary flow channel, and part of the shock wave is reflected downward back to the second arc channel. These two parts of the shock wave are constantly reflected on the inner wall of the connection between the second secondary flow channel and the second arc channel, and several vortices will be formed, which will eventually disappear due to the continuous dissipation of energy. The remaining shock waves after convergence and reflection propagate to the right and flow out through the outlet, completing an attenuation process. The anemometer records the wind speed at the outlet measurement point as v.

[0040] 2.4 Substitute the v obtained in step 2.3 into p=f(v) to obtain the shock wave overpressure p, and the measurement is completed.

[0041] The following technical effects can be achieved by adopting the present invention:

[0042] 1. The measurement method of the present invention utilizes the obstruction effect of the Tesla valve on the fluid, so that the explosion shock wave continuously dissipates energy when propagating inside it, and finally decays into a measurable strong wind. By measuring the wind speed at the outlet of the Tesla valve, the inlet overpressure is inferred, thereby realizing the rapid quantitative measurement of the explosion field shock wave overpressure.

[0043] 2. The Tesla valve-shaped flow channel in the measuring device of the present invention can adopt different size parameters to form a richer specification. In addition, multiple measuring devices can be connected in series to achieve different measuring ranges, thereby expanding the overall measuring range and improving the applicability of the device.

[0044] 3. The measuring device of the present invention has the characteristics of simple structure, flexible layout, convenient use, simple and intuitive results, low use cost and reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the overall structure of the measuring device of the present invention;

[0046] Figure 2 This is a schematic diagram of the structure of the substrate 2 of the measuring device of the present invention;

[0047] Figure 3 A top view of a substrate 2 of the measuring device of the present invention;

[0048] Figure 4 It is a left side view of the base 2 of the measuring device of the present invention;

[0049] Figure 5 This is a top perspective view of the measuring devices of the present invention connected in series. DETAILED DESCRIPTION

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, only some embodiments of the present invention are described below. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions will be clearly and completely described below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] like Figure 1 As shown, the measuring device of the present invention is generally in the form of a special-shaped rectangular parallelepiped, and is composed of a cover plate 1 and a base 2. The cover plate 1 is covered on the base 2 by bolts.

[0052] like Figure 1As shown, the cover plate 1 is a rectangular parallelepiped, with a length of L1, which is required to satisfy 0.1m<L1<0.9m, a width of W1, which is required to satisfy 0.05m<W1<0.5m, and a thickness of H1, which is required to satisfy 0.003m100MPa, density ρ1>1g / cm<h1> 3 The basic principle is that it does not deform under the action of shock waves, that is, it can be used as a solid wall.

[0053] like Figure 2 As shown, combined Figure 3 and Figure 4 The base 2 is composed of a bottom plate 21, a circle of sealing gasket strips 20 and two limit rails 22. The two limit rails 22 have the same shape and structure. The limit rails 22 are long strips and are welded on both sides of the long sides of the bottom plate 21, so that the base 2 is U-shaped when viewed from the left end. Figure 4 As shown. Figure 3 As shown, the length of the bottom plate 21 is L2, L2 = L1, the width of the bottom plate 21 is W2, which satisfies 0.05m<W2<0.3m, and the overall height of the bottom plate 21 is H2, which is required to satisfy 0.01m<H2<0.2m. Figure 2 As shown, the upper surface of the base 2 is welded with limiting guide rails 22 on both sides along the length direction, so that the cover plate 1 can be installed between the two limiting guide rails 22. Figure 4 As shown, the width W of the limiting guide rail 22 is 24 The requirement is 0.001m<W 24 <0.05m, height H of limit rail 22 24 Requirements to meet H 24 The bottom plate 21 has a Tesla valve-shaped flow channel 23 on its upper surface. The depth of the Tesla valve-shaped flow channel 23 is d1, which is required to satisfy d1<H2 and 0.01m<d1<0.02m. The width of the Tesla valve-shaped flow channel 23 is d2, which is required to satisfy d2=d1.

[0054] like Figure 2 and Figure 3 As shown, a circle of grooves are dug along the upper surfaces of both sides of the Tesla valve-shaped flow channel 23, and a circle of sealing gasket strips 20 are pasted in the grooves. The width of the sealing gasket strips 20 is W 20 (See Figure 4 )Requirement: 0.001m<W 20 <0.02m, sealing strip 20 thickness h 20 The requirement is 0.001m<h 20<0.005m, the sealing gasket strip 20 is just embedded in the groove, and the upper surface of the sealing gasket strip 20 is flush with the upper surface of the bottom plate 21 without the Tesla valve-shaped flow channel 23. The sealing gasket strip 20 is made of high-strength pressure-resistant rubber, and the hardness grade is required to meet Sh≥60. It has a certain elasticity and can fit tightly with the upper surface of the bottom plate 21 and the cover plate 1 without air leakage. The Tesla valve-shaped flow channel 23 is covered by the cover plate 1. Under the action of the sealing gasket strip 20 and the cover plate 1, the upper surface of the Tesla valve-shaped flow channel 23 is sealed, and the Tesla valve-shaped flow channel 23 becomes a pipe with a square cross-section.

[0055] like Figure 3 As shown, combined Figure 2 The Tesla valve-shaped flow channel 23 is composed of an inlet 231, a first main flow channel 232, a first secondary flow channel 233, a first arc channel 234, a transition connecting section 235, a second main flow channel 236, a second secondary flow channel 237, a second arc channel 238 and an outlet 239. The central axis of the inlet 231 coincides with the central axis of the outlet 239, and both are the central axis OO' of the Tesla valve-shaped flow channel 23, and OO' is consistent with the length direction of the bottom plate 21. The first main channel 232 is connected to the inlet 231, with an angle of α, which is required to satisfy 50°>α>10°; the first main channel 232 is connected to the first secondary channel 233, with an angle of β, which is required to satisfy β=2α; the first arc channel 234 is connected to the first main channel 232 and the first secondary channel 233; the transition section 235 is connected to the first secondary channel 233 and the second main channel 236 and is in line with each other, the second main channel 236 is connected to the second secondary channel 237, the second arc channel 238 is connected to the second main channel 236 and the second secondary channel 237, and the second secondary channel 237 is connected to the outlet 239, with an angle equal to α. The first arc channel 234 is a circular arc with a central angle of 180° and a radius of R1, which is required to satisfy R1>0.01m; the shape of the second arc channel 238 is exactly the same as that of the first arc channel 234.

[0056] The left side of the bottom plate 21 has a head protrusion 24 facing leftward, such as Figure 3 As shown, the length of the protruding portion of the head protrusion 24 is L 21 , it is required to meet 0.01m<L 21 <0.2m, the width of the head protrusion 24 is W 21 , requiring to satisfy W 21 <W1, the central axis of the head protrusion 24 coincides with the central axis OO' of the Tesla valve-shaped flow channel 23. The right side of the bottom plate 21 has a tail groove 25 that is concave to the left, and the depth of the concave part is L 22 , requiring L 22 =L 21 , width W 22 , requiring W 22 =W 21The center axis of the tail groove 25 coincides with the center axis OO' of the Tesla valve. The base 2 is made of high-strength material, which is required to meet the following requirements: yield strength σ2>100MPa, density ρ2>1g / cm 3 The basic principle is that it does not deform under the impact of the shock wave, that is, it can be used as a solid wall to avoid changing the shape of the Tesla valve-shaped flow channel after the impact, thereby affecting the measurement accuracy. An even number of edge bolt holes and an even number of middle bolt holes are opened on the bottom plate 21. The basic principle for selecting the positions of the edge bolt holes and the middle bolt holes is to ensure that the cover plate 1 is firmly connected to the bottom plate 21 while avoiding the overlap of the edge bolt holes and the middle bolt holes with the Tesla valve-shaped flow channel to affect the use effect.

[0057] A specific embodiment 1 is given as follows:

[0058] Some of the main parameters in Example 1 are as follows: α = 23°, L2 = L1 = 0.266m, W1 = 0.115m, W2 = 0.135m, H2 = 0.02m, H1 = W 24 =H 24 =0.01m, W 21 =W 22 =0.05m, d1=d2=0.01m. R1=0.025m. The bottom plate 21 has 10 bolt holes for connection with the cover plate 1. Figure 3 As shown, there are six edge bolt holes 281-286 (respectively the first edge bolt hole 281, the second edge bolt hole 282, the third edge bolt hole 283, the fourth edge bolt hole 284, the fifth edge bolt hole 285, and the sixth edge bolt hole 286), and four middle bolt holes 291-294 (respectively the first middle bolt hole 291, the second middle bolt hole 292, the third middle bolt hole 293, and the fourth middle bolt hole 294). The distance between the first edge bolt hole 281, the second edge bolt hole 282, and the third edge bolt hole 283 and the nearest limit guide rail 22 is d 21 , requiring to satisfy d 21 >0.01m; the distance between the first edge bolt hole 281 and the nearest end of the limiting guide rail 22 is D 21 , requiring D 21 >0.01m; the distance between the third edge bolt hole 283 and the nearest end of the limiting guide rail 22 is D 23 , requiring D 23 >0.01m; the distance between the second edge bolt hole 282 and the third edge bolt hole 283 along the OO' direction is D 22 , requiring D 22 >0.015m; the distance between the fourth edge bolt hole 284, the fifth edge bolt hole 285, the sixth edge bolt hole 286 and the nearest limit rail 22 is d 22 , requiring to satisfy d22 >0.01m. The first middle bolt hole 291 is set at the center of the first arc 234, the fourth middle bolt hole 294 is set at the center of the second arc 238, the line connecting the second middle bolt hole 292 and the first middle bolt hole 291 is parallel to the OO' direction, and the line connecting the third middle bolt hole 293 and the fourth middle bolt hole 294 is parallel to the OO' direction; the line connecting the first middle bolt hole 291 and the third middle bolt hole 293 is parallel to the width direction of the bottom plate 21, and the line connecting the second middle bolt hole 292 and the fourth middle bolt hole 294 is parallel to the width direction of the bottom plate 21. The inner diameter of the edge bolt hole and the middle bolt hole is D1, and it is required to satisfy D1>0.008m.

[0059] The number M of the cover plate bolt holes 11 is equal to the sum of the number of the edge bolt holes and the middle bolt holes on the bottom plate 21, and the positions correspond to the positions of the edge bolt holes and the middle bolt holes one by one, and the inner diameter is equal to D1. In Example 1, the bottom plate 21 is provided with 10 bolt holes for connection with the cover plate 1, wherein the positions of the cover plate bolt holes 11 are specifically determined as follows: the cover plate 1 is attached to the upper surface of the bottom plate 21 and the cover plate 1 is ensured to be sandwiched between the two limiting guide rails 22, and at the same time, the left end face of the cover plate 1 is flush with the left end face of the head protrusion 24 (i.e., the plane where the inlet 231 is located) and is coplanar. At this time, in the top view of the measuring device, the positions of the eight bolt holes on the bottom plate 21 except the third edge bolt hole 283 and the sixth edge bolt hole 286 coincide with the positions of the eight cover plate bolt holes 11 of the cover plate 1; slide the cover plate 1 to the right along the limit guide rail 22, so that the left end surface of the cover plate 1 is coplanar with the left end surface of the tail groove 25 (i.e., the plane where the outlet 239 is located), and at this time, in the top view of the device, the third edge bolt hole 283 and the sixth edge bolt hole 286 of the bottom plate 21 coincide with the positions of the remaining two cover plate bolt holes 11 of the cover plate 1. Ensure that the cover plate 1 and the bottom plate 21 are tightly fitted through the sealing gasket strip 20, and the formed Tesla valve-shaped flow channel 23 has good radial air tightness.

[0060] In Example 1, Figure 3 As shown, combined Figure 4 Two long connecting pins 272 are arranged on the right side of the bottom plate 21, and two long connecting slots 262 are dug at corresponding positions along the length direction of the bottom plate 21 on the left end surface of the bottom plate 21; two short connecting slots 26 are dug at the left end surface of the head protrusion 24, and two short connecting pins 271 are arranged at corresponding positions along the length direction of the bottom plate 21 on the right end surface of the tail groove 25 at the two short connecting slots 261, which are used to connect multiple measuring devices of the same specification to achieve a larger measuring range, avoid changing the measuring parameters, reduce the types of device sizes, and achieve the effect of reducing the production cost.

[0061] The process of using the present invention to measure the explosion field shock wave is:

[0062] In the first step, the measuring device of the present invention is calibrated using an existing free-field pressure sensor (in this embodiment, a 6233AA0250 free-field pressure sensor from Kistler Company is used) to obtain a calibrated measuring device and establish a conversion equation between the outlet wind speed and the inlet overpressure.

[0063] The method is:

[0064] 1.1 Let the number of experiments n=1, let the total number of experiments be N, and in this embodiment N is 8. Initialize the proportional distance k between the entrance 231 and the explosion center n =2;

[0065] 1.2 Check whether the air tightness of the measuring device is good. The method is: block the inlet 231 and the outlet 239 with your fingers or other objects, then slowly immerse the measuring device in clean water to observe whether there are bubbles leaking out. If no obvious bubbles are seen, it means that the air tightness is good and the calibrated measuring device is obtained. Go to 1.3; if bubbles leak out, go to 1.8.

[0066] 1.3 Fix the measuring device and the free-field pressure sensor to the corresponding position, and ensure that the proportional distance between the inlet 231 and the explosion center and the proportional distance between the free-field pressure sensor and the explosion center are equal to k n At the same time, the anemometer probe is fixed so that it can work normally, that is, directly measure the wind speed at the outlet 239. Specifically, the distance between the anemometer probe and the outlet 239 is required to be no more than 10 mm. The measuring device is adjusted so that the center OO' of the Tesla valve-shaped flow channel 23 is aligned with the explosion center.

[0067] 1.4 at proportional distance k n Under this condition, the wind speed at the outlet 239 is measured and k is obtained. n The corresponding wind speed v at outlet 239 n , and a free-field pressure sensor is used to measure the shock wave overpressure p at this proportional distance n If the wind speed at outlet 239 exceeds the range of the anemometer or there is no response, go to 1.5 to add another set of this device in series. If the wind speed at outlet 239 does not exceed the range of the anemometer, go to 1.6.

[0068] 1.5 Connect one set of this device in series. The method of series connection is:

[0069] 1.5.1 As Figure 5 As shown, prepare another set of measuring devices with the same specifications as the measuring devices before the series connection, and record the measuring device before the series connection as No. ① ( Figure 5 The left device in the figure), the other set of measuring devices with the same specifications that need to be connected in series is No. ② ( Figure 5 device in the right section).

[0070] 1.5.2 Insert the two long connecting pins 272 on the right side of the base 2 of the measuring device No. ① into the two long connecting slots 262 on the left side of the base 2 of the measuring device No. ②, and insert the two short connecting pins 271 into the two short connecting slots 261 on the left side of the base 2 of the measuring device No. ②.

[0071] 1.5.3 Place the cover plate 1 of device No. ① between the two limiting guide rails 22 and close to the sealing gasket strip 20 on the upper surface of the bottom plate 21 of device No. ①. At the same time, align the left plane of the cover plate 1 of device No. ① with the left plane of the head protrusion 24 of device No. ① so that they are coplanar. Tighten the connection with bolts at the eight positions where the bolt holes of the cover plate 1 of device No. ① and the bottom plate 21 of device No. ① overlap (edge ​​bolt holes 281, 282, 284, 285, four middle bolt holes 291-294).

[0072] 1.5.4 Place the cover plate 1 of device ② between the two limiting guide rails 22 and close to the sealing strip 20 on the upper surface of the bottom plate 21 of device ②, and make the left plane of the cover plate 1 of device ② close to the right plane of the cover plate 1 of device ①, and tighten the bolts at the 10 positions where the bolt holes of the cover plate 1 of device ② overlap with the bottom plates 21 of devices ① and ②. The essence is to use the cover plate 1 of device ② as a connector to achieve the effect of connecting and fixing the two bottom plates 21.

[0073] 1.5.5 Go to 1.1 and calibrate the measuring devices connected in series.

[0074] 1.6 At this time, we get k n The corresponding wind speed v at outlet 239 n , if n≤N, let n=n+1, let k n =(0.1n+0.9)k1, then turn to 1.3; if n>N, then turn to 1.7.

[0075] 1.7 N groups of data points consisting of the wind speed at the outlet 239 and the shock wave overpressure at the inlet 231, namely (v1, p1), ..., (v n , p n ),…,(v N , p N ) is plotted in a rectangular coordinate system, and the distribution of the data points is observed. If the distribution of the data points is linear, a linear fit is performed, otherwise a high-order polynomial fit is performed to obtain the conversion equation between the outlet wind speed and the inlet overpressure of the measuring device of the present invention. Let the equation be p=f(v), where p is the shock wave overpressure at the inlet 231, and v is the measured wind speed at the outlet 239, and then go to the second step.

[0076] 1.8 Solve the airtightness problem of the measuring device by checking whether the sealing strip 20 is flat and undamaged, and whether the sealing strip 20 fits tightly with the bottom plate 21. If there is any abnormality, replace it in time, and adjust the tightness of the connecting bolts to make the cover plate 1 fit tightly with the sealing strip 20. After completion, go to 1.2.

[0077] The second step is to measure the shock wave overpressure using a calibrated measuring device, using the following method:

[0078] 2.1 Fix the calibrated measuring device to the position to be measured, and fix the anemometer measuring probe so that it can work normally, that is, directly measure the wind speed at the outlet 239. Specifically, the distance between the anemometer measuring probe and the outlet 239 is required to be no more than 10 mm. Align the central axis OO' of the measuring device inlet 231 with the explosion center, or adjust it to ensure that the central axis OO' is perpendicular to the plane wave front of the shock wave to be measured.

[0079] 2.2 Create an explosion shock wave by detonating explosives or other means. The shock wave is transmitted to the measuring device. At this time, the inlet 231 receives the shock wave and transmits it into the first main channel 232. The first secondary channel 233 diverts a part of the shock wave in the first main channel 232. The first arc channel 234 receives the shock wave propagated from the first main channel 232 and introduces the shock wave into the connection between the first secondary channel 233 and the transition connection section 235, so that the shock wave converges and reflects with the shock wave in the first secondary channel 233 at this connection. Part of the shock wave is reflected to the left into the first secondary channel 233, and part of the shock wave is reflected upward back into the first arc channel 234. These two parts of the shock wave are constantly reflected on the inner wall of the connection between the first secondary channel 233 and the transition connection section 235, and several vortices will be formed, which will eventually disappear due to the continuous dissipation of energy. The remaining shock waves after convergence and reflection flow to the right through the transition connection section 235 and propagate to the second main channel 236.

[0080] 2.3 Similarly, the second secondary flow channel 237 diverts a portion of the shock wave front in the second main flow channel 236, and the second arc channel 238 receives the shock wave propagated from the second main flow channel 236 and guides the shock wave into the connection between the second secondary flow channel 237 and the second arc channel 238, so that the shock wave front converges and reflects with the shock wave in the second secondary flow channel 237 at the connection. A portion of the shock wave front is reflected to the left into the second secondary flow channel 237, and a portion of the shock wave is reflected downward back into the second arc channel 238. These two portions of shock waves are constantly reflected on the inner wall of the connection between the second secondary flow channel 237 and the second arc channel 238, and several vortices are formed, which eventually disappear due to the continuous dissipation of energy. The remaining shock waves after convergence and reflection propagate to the right and flow out through the outlet 239, completing an attenuation process. The anemometer records the wind speed at the measuring point of the outlet 239 as v.

[0081] 2.4 Substitute the v obtained in step 2.3 into p=f(v) to obtain the shock wave overpressure p, and the measurement is completed.

[0082] A specific example of a measurement test performed according to the measurement steps of Example 1 is as follows: at an initial proportional distance of n=1, k1=2, the incident shock wave overpressure p1=0.197MPa measured by the free-field pressure sensor at the inlet 231, but the wind speed measured at the outlet 239 exceeds the anemometer range. After connecting a set of the present device in series according to step 1.5, the wind speed at the outlet 239 obtained by re-measurement is v1=51.83m / s. Let N = 8, and according to the measurement steps, a total of 8 groups of data are obtained, namely (51.83, 0.197), (49.96, 0.159), (46.71, 0.132), (44.62, 0.111), (43.48, 0.095), (41.69, 0.082), (39.42, 0.072), (37.85, 0.064). These 8 groups of data points are plotted in a rectangular coordinate system. It can be observed that they are roughly parabolic distributions. The second-order polynomial fitting is adopted: p = f(v) = Av 2 +Bv+C, after fitting, we get A=0.000394, B=-0.0261, C=0.488, that is, p=f(v)=0.000394v 2 -0.0261v+0.488, inlet overpressure p in MPa, outlet wind speed v in m / s, calibration completed. In this specific example, to verify the measurement effect, the free field pressure sensor was used to measure the inlet overpressure p0 = 0.159 MPa, and the anemometer measured the outlet wind speed v0 = 47.74 m / s. Substituting v0 into f(v) yields f(v0) = 0.140 MPa, which is 11.9% error from the measured p0, within the acceptable range, and the measurement is completed.

[0083] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A shock wave overpressure measuring device based on Tesla valve flow channel, characterized in that The shock wave overpressure measuring device based on the Tesla valve flow channel is generally in the form of a special-shaped rectangular parallelepiped, and is composed of a cover plate (1) and a base (2), wherein the cover plate (1) is covered on the base (2) by bolts; The cover plate (1) is a rectangular parallelepiped with a length of L1, a width of W1 and a thickness of H1. The cover plate (1) is provided with M cover plate bolt holes (11), where M is a positive even number. The cover plate (1) is made of a high-strength material, which is capable of not deforming under the action of a shock wave. The base (2) is composed of a bottom plate (21), a circle of sealing gasket strips (20) and two limiting guide rails (22), the two limiting guide rails (22) having the same shape and structure; the limiting guide rails (22) are long strips and are welded to the two sides of the long sides of the bottom plate (21), so that the base (2) is U-shaped when viewed from the left end; the length of the bottom plate (21) is L2, L2=L1, the width of the bottom plate (21) is W2, and the overall height of the bottom plate (21) is H2; the limiting guide rails (22) are welded on both sides of the upper surface of the base (2) along the length direction, and the cover plate (1) is installed between the two limiting guide rails (22); the width of the limiting guide rail (22) is W 24 , the height of the limiting guide rail (22) is H 24 A Tesla valve-shaped flow channel (23) is provided on the upper surface of the bottom plate (21), and the depth of the Tesla valve-shaped flow channel (23) is d1; the width of the Tesla valve-shaped flow channel (23) is d2; A circle of grooves is dug on the upper surfaces of both sides of the Tesla valve-shaped flow channel (23) along the Tesla valve-shaped flow channel (23), and a circle of sealing gasket strips (20) are pasted in the grooves. The width of the sealing gasket strips (20) is W. 20 , the thickness of the sealing gasket strip (20) is h 20 The sealing gasket strip (20) is embedded in the groove, and the upper surface of the sealing gasket strip (20) is flush with the upper surface of the bottom plate (21) provided with the Tesla valve-shaped flow channel (23); the sealing gasket strip (20) is made of high-strength pressure-resistant rubber, and is tightly fitted with the upper surface of the bottom plate (21) and the cover plate (1) to prevent air leakage; the upper surface of the Tesla valve-shaped flow channel (23) is covered by the cover plate (1), and the upper surface of the Tesla valve-shaped flow channel (23) is sealed under the action of the sealing gasket strip (20) and the cover plate (1), and the Tesla valve-shaped flow channel (23) becomes a pipe with a square cross section; The Tesla valve-shaped flow channel (23) is composed of an inlet (231), a first main flow channel (232), a first secondary flow channel (233), a first arc channel (234), a transition connection section (235), a second main flow channel (236), a second secondary flow channel (237), a second arc channel (238) and an outlet (239); the central axis of the inlet (231) coincides with the central axis of the outlet (239), and both are the central axis OO' of the Tesla valve-shaped flow channel (23), and OO' is consistent with the length direction of the bottom plate (21); the first main flow channel (232) is connected to the inlet (231), and the angle is α; the first main flow channel (232) and the first secondary flow channel (233) are connected, and the included angle β=2α; the first arc channel (234) is connected with the first main channel (232) and the first secondary channel (233); the transition connecting section (235) is connected with the first secondary channel (233) and the second main channel (236) and is in the same line, the second main channel (236) is connected with the second secondary channel (237), the second arc channel (238) is connected with the second main channel (236) and the second secondary channel (237), and the second secondary channel (237) is connected with the outlet (239), and the included angle is equal to α; the first arc channel (234) is a circular arc; the second arc channel (238) is the same shape as the first arc channel (234); The left side of the bottom plate (21) has a head protrusion (24) facing leftward, and the protrusion portion of the head protrusion (24) has a length of L 21 , the width of the head protrusion (24) is W 21 The central axis of the head protrusion (24) coincides with the central axis OO' of the Tesla valve-shaped flow channel (23); the right side of the bottom plate (21) has a tail groove (25) that is concave to the left, and the depth of the concave part is L 22 , width W 22 , the center axis of the tail groove (25) coincides with the center axis OO' of the Tesla valve; the base (2) is made of high-strength material, and the high-strength material is not deformed under the action of shock waves; an even number of edge bolt holes and an even number of middle bolt holes are opened on the bottom plate (21), and the principle of selecting the positions of the edge bolt holes and the middle bolt holes is to ensure that the cover plate (1) and the bottom plate (21) are firmly connected while avoiding the overlap of the positions of the edge bolt holes and the middle bolt holes with the Tesla valve flow channel; The number M of the cover plate bolt holes (11) is equal to the sum of the number of edge bolt holes and middle bolt holes on the bottom plate (21), and the positions correspond one-to-one to the positions of the edge bolt holes and the middle bolt holes; The right side of the bottom plate (21) is provided with two long connecting pins (272), and the left end surface of the bottom plate (21) is dug with two long connecting slots (262) at corresponding positions along the length direction of the bottom plate (21); the left end surface of the head protrusion (24) is dug with two short connecting slots (261), and the right end surface of the tail groove (25) is provided with two short connecting pins (271) at corresponding positions along the length direction of the bottom plate (21) and the two short connecting slots (261).

2. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The length L1 of the cover plate satisfies 0.1m<L1<0.9m, the width W1 satisfies 0.05m<W1<0.5m, and the thickness H1 satisfies 0.003m<H1<0.05m.

3. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The high-strength material used in the cover plate (1) has a yield strength σ1>100 MPa and a density ρ1>1 g / cm 3 The high-strength material used in the substrate (2) satisfies the following requirements: yield strength σ2>100MPa, density ρ2>1g / cm 3 The high-strength pressure-resistant rubber used in the sealing strip (20) has a hardness grade of Sh≥60.

4. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The width W2 of the bottom plate (21) satisfies 0.05m<W2<0.3m, and the overall height H2 of the bottom plate (21) satisfies 0.01m<H2<0.2m; the width W2 of the limiting guide rail (22) 24 Satisfy 0.001m<W 24 <0.05m, height H of the limit guide rail (22) 24 >0.005m; the depth d1 of the Tesla valve-shaped flow channel (23) satisfies d1<H2 and 0.01m<d1<0.02m; the width d2 of the Tesla valve-shaped flow channel (23) = d1; the width W of the sealing gasket strip (20) 20 Satisfy 0.001m<W 20 <0.02m, thickness h of sealing strip (20) 20 Satisfy 0.001m<h 20 <0.005m.

5. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The angle α between the first main flow channel (232) and the inlet (231) of the Tesla valve-shaped flow channel (23) satisfies 50°>α>10°; the center angle of the first arc channel (234) is 180°, and the radius R1 is greater than 0.01 m.

6. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The head protrusion (24) has a protruding portion length L 21 Satisfy 0.01m<L 21 <0.2m, width W of head protrusion (24) 21 <W1; Depth L of the recessed portion of the tail groove (25) 22 =L 21 , width W 22 =W 21 .

7. A shock wave overpressure measuring device based on a Tesla valve flow channel as claimed in claim 1, characterized in that The bottom plate (21) is provided with 10 bolt holes for connection with the cover plate (1), wherein the six edge bolt holes are a first edge bolt hole (281), a second edge bolt hole (282), a third edge bolt hole (283), a fourth edge bolt hole (284), a fifth edge bolt hole (285), and a sixth edge bolt hole (286), and the four middle bolt holes are a first middle bolt hole (291), a second middle bolt hole (292), a third middle bolt hole (293), and a fourth middle bolt hole (294); the distance between the first edge bolt hole (281), the second edge bolt hole (282), and the third edge bolt hole (283) and the nearest limiting guide rail (22) is d 21 , satisfying d 21 >0.01m; the distance between the first edge bolt hole (281) and the nearest end of the limiting guide rail (22) is D 21 , satisfying D 21 >0.01m; the distance between the third edge bolt hole (283) and the nearest end of the limiting guide rail (22) is D 23 , satisfying D 23 >0.01m; the distance between the second edge bolt hole (282) and the third edge bolt hole (283) along the OO' direction is D 22 , satisfying D 22 >0.015m; the distance between the fourth edge bolt hole (284), the fifth edge bolt hole (285), the sixth edge bolt hole (286) and the nearest limit rail (22) is d 22 , satisfying d 22 >0.01m; the first middle bolt hole (291) is arranged at the center point of the first arc (234), the fourth middle bolt hole (294) is arranged at the center point of the second arc (238), the line connecting the second middle bolt hole (292) and the first middle bolt hole (291) is parallel to the OO' direction, and the line connecting the third middle bolt hole (293) and the fourth middle bolt hole (294) is parallel to the OO' direction; the line connecting the first middle bolt hole (291) and the third middle bolt hole (293) is parallel to the width direction of the bottom plate (21), and the line connecting the second middle bolt hole (292) and the fourth middle bolt hole (294) is parallel to the width direction of the bottom plate (21); the inner diameter of the edge bolt hole and the middle bolt hole is D1, satisfying D1>0.008m; the inner diameter of the cover plate bolt hole (11) is equal to D1; the position of the cover plate bolt hole (11) is full Foot: The cover plate (1) is attached to the upper surface of the bottom plate (21) and the cover plate (1) is sandwiched between the two limiting guide rails (22), and at the same time, the left end surface of the cover plate (1) is flush with the left end surface of the head protrusion (24), i.e., the plane where the inlet (231) is located; at this time, in the top view of the measuring device, the positions of the eight bolt holes on the bottom plate (21) except the third edge bolt hole (283) and the sixth edge bolt hole (286) coincide with the positions of the eight cover plate bolt holes (11) of the cover plate (1); the cover plate (1) is slid rightward along the limiting guide rails (22) so that the left end surface of the cover plate (1) is coplanar with the left end surface of the tail groove (25), i.e., the plane where the outlet (239) is located; at this time, in the top view of the device, the third edge bolt hole (283) and the sixth edge bolt hole (286) of the bottom plate (21) coincide with the positions of the remaining two cover plate bolt holes (11) of the cover plate (1).

8. A method for measuring explosion field shock waves using the shock wave overpressure measuring device based on Tesla valve flow channel as claimed in claim 1, characterized in that The following steps are involved: The first step is to calibrate the measuring device using a free-field pressure sensor to obtain a calibrated measuring device and establish a conversion equation between outlet wind speed and inlet overpressure; the method is: 1.1 Let the number of experiments n = 1, let the total number of experiments be N, N is a positive integer and N ≥ 8; initialize the proportional distance k between the entrance (231) and the explosion center n =1m / kg 3 ; 1.2 Check whether the air tightness of the measuring device is good. If it is, it means that the measuring device is calibrated well, go to 1.3; if it is not, go to 1.8; 1.3 Fix the measuring device and the free-field pressure sensor to the corresponding position, and ensure that the proportional distance between the inlet (231) and the explosion center and the proportional distance between the free-field pressure sensor and the explosion center are equal to k n At the same time, the anemometer measuring probe is fixed so that it can work normally, that is, the outlet (239) wind speed is directly measured, and the distance between the anemometer measuring probe and the outlet (239) is required to be no more than 10 mm; the measuring device is adjusted so that the center of the Tesla valve-shaped flow channel (23) OO 'is aligned with the explosion center position; 1.4 at proportional distance k n Under the condition, the wind speed at the outlet (239) is measured and k is obtained. n The corresponding wind speed v at the outlet (239) n , and a free-field pressure sensor is used to measure the shock wave overpressure p at this proportional distance n If the wind speed at the outlet (239) exceeds the anemometer range or there is no response, go to 1.5 to add another set of this device in series; if the wind speed at the outlet (239) does not exceed the anemometer range, go to 1.6; 1.5 Connect one set of this device in series. The method of series connection is: 1.5.1 Prepare another set of measuring devices with the same specifications as the measuring device before the series connection. The measuring device before the series connection is numbered as ①, and the other set of measuring devices with the same specifications to be connected in series is numbered as ②; 1.5.2 Insert the two long connecting pins (272) on the right side of the base (2) of the measuring device No. ① into the two long connecting slots (262) on the left side of the base (2) of the measuring device No. ②, and insert the two short connecting pins (271) into the two short connecting slots (261) on the left side of the base (2) of the measuring device No. ②; 1.5.3 Place the cover plate (1) of device ① between the two limiting guide rails (22) and close to the sealing strip (20) on the upper surface of the bottom plate (21) of device ①. At the same time, align the left plane of the cover plate (1) of device ① with the left plane of the head protrusion (24) of device ①. Tighten the bolts at the position where the bolt holes of the cover plate (1) of device ① and the bottom plate (21) of device ① overlap; 1.5.4 Place the cover plate (1) of device ② between the limiting guide rails (22) on both sides and close to the sealing gasket strip (20) on the upper surface of the bottom plate (21) of device ②. At the same time, make the left plane of the cover plate (1) of device ② close to the right plane of the cover plate (1) of device ①. Use bolts to tighten the bolts at the position where the bolt holes of the cover plate (1) of device ② overlap with the bottom plates (21) of devices ① and ②. Use the cover plate (1) of device ② as a connecting piece to connect and fix the two bottom plates (21). 1.5.5 to 1.1; 1.6 At this time, we get k n The corresponding wind speed v at the outlet (239) n , if n≤N, let n=n+1, let k n =(0.1n+0.9)k1, turn to 1.3; if n>N, turn to 1.7; 1.7 N groups of data points consisting of the wind speed at the outlet (239) and the shock wave overpressure at the inlet (231), namely (v1, p1), ..., (v n , p n ),…,(v N , p N ) is plotted in a rectangular coordinate system, and the distribution of the data points is observed. If the distribution of the data points is linear, a linear fit is performed, otherwise a high-order polynomial fit is performed to obtain a conversion equation between the outlet wind speed and the inlet overpressure of the measuring device. Let the equation be p=f(v), where p is the shock wave overpressure at the inlet (231), and v is the measured wind speed at the outlet (239), and then go to the second step; 1.8 Solve the airtightness problem of the measuring device. After completion, go to 1.2; The second step is to measure the shock wave overpressure using a calibrated measuring device, using the following method: 2.1 Fix the calibrated measuring device to the position to be measured, and fix the anemometer measuring probe so that it can work normally, that is, directly measure the outlet (239) wind speed, and specifically require that the distance between the anemometer measuring probe and the outlet (239) is not greater than 10 mm; align the central axis OO' of the measuring device inlet (231) with the explosion center position, or adjust it to ensure that the central axis OO' is perpendicular to the plane wave front of the shock wave to be measured; 2.2 The shock wave of the explosion is generated by detonating explosives or other methods; the shock wave is transmitted to the measuring device, at which time the inlet (231) receives the shock wave and transmits it to the first main channel (232), the first secondary channel (233) diverts a part of the shock wave in the first main channel (232), the first arc channel (234) receives the shock wave propagated from the first main channel (232) and guides the shock wave to the connection between the first secondary channel (233) and the transition connecting section (235), so that the shock wave is connected to the first secondary channel (233) at the connection. The shock waves in the flow channel (233) converge and reflect; a portion of the shock waves is reflected leftward into the first secondary flow channel (233), and a portion of the shock waves is reflected upward back into the first arc channel (234); these two portions of shock waves are continuously reflected on the inner wall of the connection between the first secondary flow channel (233) and the transition connection section (235), and a number of vortices are formed, which eventually disappear due to continuous energy dissipation; the remaining shock waves after convergence and reflection flow rightward through the transition connection section (235) and propagate into the second main flow channel (236); 2.3 The second secondary flow channel (237) diverts a portion of the shock wave front in the second main flow channel (236), and the second arc channel (238) receives the shock wave propagated from the second main flow channel (236) and guides the shock wave to the connection between the second secondary flow channel (237) and the second arc channel (238), so that the shock wave front converges and reflects with the shock wave in the second secondary flow channel (237) at the connection; a portion of the shock wave front is reflected to the left into the second secondary flow channel (237), and a portion of the shock wave is reflected downward back into the second arc channel (238); these two portions of shock waves are continuously reflected on the inner wall of the connection between the second secondary flow channel (237) and the second arc channel (238), and a number of vortices are formed, which eventually disappear due to continuous energy dissipation; the remaining shock waves after convergence and reflection propagate to the right and flow out through the outlet (239), completing an attenuation process; the anemometer records the wind speed at the measuring point of the outlet (239) as v; 2.4 Substitute the v obtained in step 2.3 into p=f(v) to obtain the shock wave overpressure p, and the measurement is completed.

9. The method for measuring explosion field shock waves using the shock wave overpressure measuring device based on the Tesla valve flow channel according to claim 8, characterized in that The method for confirming whether the air tightness of the measuring device is good in step 1.2 is: after blocking the inlet (231) and the outlet (239) with fingers or other objects, slowly immerse the entire measuring device in clean water to observe whether there are bubbles leaking out; if no obvious bubbles are seen, it means that the air tightness is good, and if bubbles leak out, it means that the air tightness is not good.

10. The method for measuring explosion field shock waves using the shock wave overpressure measuring device based on the Tesla valve flow channel according to claim 8, characterized in that The method for solving the airtightness problem of the measuring device in step 1.8 is: check whether the sealing gasket strip (20) is flat and not damaged, check whether the sealing gasket strip (20) is tightly fitted with the bottom plate (21), replace it if there is any abnormality, and adjust the tightness of the connecting bolts so that the cover plate (1) and the sealing gasket strip (20) are tightly fitted.

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