Gradient design type shock tube vibration and noise reduction device for engineering

Abstract

The invention relates to the technical field of vibration and noise reduction of shock tube testing devices in the engineering anti-explosion industry, in particular to a gradient design type shock tube vibration and noise reduction device for engineering. Comprising a shock tube, an injection silencing module and a vibration and noise reduction module. The shock tube is connected with the injection silencing module; the vibration and noise reduction module is connected with the injection noise elimination module; the shock tube, the injection noise elimination module and the vibration and noise reduction module are coaxially arranged. According to the gradient design type shock tube vibration and noise reduction device for engineering, airflow and sound wave propagation paths are optimized through gradient design, so that noise and vibration generated in the working process of the shock tube are effectively reduced, and meanwhile the aerodynamic performance and operation efficiency of the shock tube are kept. The vibration and noise reduction module formed by periodically arranged functional units forms an acoustic black hole structure, compared with a traditional method, the acoustic black hole structure has better acoustic and elastic wave control physical characteristics, the propagation speed of shock waves can be effectively reduced, and reflection at the tail end of a boundary is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction and noise reduction of a shock tube test device in the engineering explosion-proof industry, in particular to a gradient-designed shock tube vibration reduction and noise reduction device for engineering use. Background Art

[0002] In modern engineering applications, shock tubes, as an efficient gas dynamic device, are widely used in aerospace, defense, and automotive fields to simulate phenomena such as high-speed airflow and explosion waves. However, since the shock tube generates strong sound waves and shock waves during operation, these sound waves and shock waves not only interfere with the normal operation of the equipment, but also may cause significant noise pollution to the surrounding environment. Therefore, how to effectively reduce vibration and noise has become an important topic in the research of shock tube technology. In the prior art, although several methods of vibration reduction and noise reduction have been proposed, such as adding sound-absorbing materials in the shock tube and adopting complex sound insulation structures, these methods generally have problems such as low efficiency, large volume, high cost, or negative impact on the performance of the shock tube. For example, traditional sound-absorbing materials often cannot work stably for a long time under high temperature and high pressure environments, resulting in a decline in vibration reduction effect. In addition, complex sound insulation structures not only increase the volume and weight of the device, but may also affect the aerodynamic performance of the shock tube and reduce its efficiency. In recent years, researchers have tried to improve the vibration reduction and noise reduction performance of the shock tube by improving the flow structure and materials inside the shock tube. For example, some progress has been made by introducing porous media, flow control devices and other technologies to control the propagation paths of sound waves and shock waves. However, the implementation process of these technologies is complicated and difficult to operate, and their adaptability and effectiveness are still limited to noise fluctuations of different frequencies and intensities.

[0003] How to effectively reduce noise and improve vibration characteristics while maintaining the performance and ease of operation of the shock tube is an urgent problem to be solved in the current technical field. Summary of the invention

[0004] The purpose of the present invention is to provide a gradient-designed vibration and noise reduction device for engineering shock tubes, which can reduce the vibration and noise of engineering shock tubes under compressed air explosions, can be used for vibration and noise control in large-scale indoor shock tube tests, and has strong operability; the method for regulating test parameters such as vibration and noise frequency, amplitude, and action direction caused by different high-speed shock waves during the test is simple, and has a wide range of applications; it is composed of a traditional engineering shock tube, an injection silencer, and a simple vibration and noise reduction device, which is cheap and has good economic benefits; all parts can be disassembled, and installation and replacement of test pieces are simple and convenient.

[0005] The present invention adopts the following technical solution:

[0006] The gradient-designed engineering shock tube vibration reduction and noise reduction device described in the present invention comprises a shock tube, an injection silencer module, and a vibration reduction and noise reduction module; the shock tube is connected to the injection silencer module; the vibration reduction and noise reduction module is connected to the injection silencer module; the shock tube, the injection silencer module and the vibration reduction and noise reduction module are coaxially arranged.

[0007] The invention discloses a gradient-designed shock tube vibration and noise reduction device for engineering use, wherein the injection silencer module is a tube body with flanges at both ends; the tube body is provided with a plurality of cylindrical perforated exhaust columns; a plurality of supporting ribs are provided between the flanges at both ends of the tube body; and the plurality of supporting ribs are parallel to each other.

[0008] The invention discloses a gradient-designed shock tube vibration and noise reduction device for engineering use, in which a plurality of cylindrical perforated exhaust columns are arranged in an annular pattern along the circumference of the tube body; a plurality of continuous through-going frustum-shaped holes are arranged in the cylindrical perforated exhaust column; the large-diameter openings of the frustum-shaped holes are sequentially directed toward the outside of the tube body; and a supporting rib plate is provided between adjacent cylindrical perforated exhaust columns.

[0009] The invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering use, wherein the vibration reduction and noise reduction module comprises a tube, in which an annular wave stop device is arranged; the annular wave stop device is composed of a plurality of annular wave stops, a noise reduction hole is arranged at the center of the annular wave stop, and the inner radius of the plurality of noise reduction holes in the annular wave stop device changes according to a power law function to realize acoustic impedance adjustment.

[0010] The gradient-designed shock tube vibration and noise reduction device for engineering use described in the present invention also includes a rigid support ring; a rigid support ring is arranged between every two adjacent annular wave stops in the annular wave stop device; the rigid support ring and the annular wave stops and the tube in the annular wave stop device are fixed to each other by welding.

[0011] The gradient-designed shock tube vibration and noise reduction device for engineering use described in the present invention has the inner diameters of the noise reduction holes of the plurality of annular wave stop devices decreasing from large to small along the axial direction of the tube, and then increasing from small to large in sequence.

[0012] In the gradient-designed shock tube vibration and noise reduction device for engineering use described in the present invention, the inner radius of the noise reduction hole follows the power law function change as follows:

[0013] r i =εx m +r0

[0014] Where r0 is a constant, ε is the first power law constant, m is the power law exponent, and x is the distance from the ring to the center point.

[0015] The invention discloses a gradient-designed shock tube vibration and noise reduction device for engineering use, wherein the major diameter of the frustum-shaped hole in the cylindrical perforated exhaust column is smaller than the inner diameter of the cylindrical perforated exhaust column.

[0016] The invention discloses a gradient-designed shock tube vibration and noise reduction device for engineering use, wherein the cylindrical perforated exhaust column is made of high-strength steel, and the major diameter of the frustum-shaped hole is 2 / 3 of that of the cylindrical perforated exhaust column.

[0017] Beneficial effects of the present invention:

[0018] 1. The gradient-designed engineering shock tube vibration reduction and noise reduction device provided by the present invention utilizes gradient design to optimize the airflow and sound wave propagation path, thereby effectively reducing the noise and vibration generated by the shock tube during operation while maintaining the aerodynamic performance and operating efficiency of the shock tube; the vibration reduction and noise reduction module composed of periodically arranged functional units forms an acoustic black hole structure, which has better acoustic and elastic wave manipulation physical properties than traditional methods, and can effectively reduce the propagation speed of the shock wave and reduce the reflection at the boundary end.

[0019] 2. The gradient-designed shock tube vibration and noise reduction device for engineering use provided by the present invention has an injection silencer module that is provided with a wave-absorbing section to reduce the peak pressure effect of the shock wave, thereby reducing the shock wave to a safe range and suppressing the airflow from forming a vortex flow at the tube mouth.

[0020] 3. The gradient-designed engineering shock tube vibration and noise reduction device provided by the present invention has a linearly varying spacing of the annular wave stop device in the vibration and noise reduction module, which retains the slow sound effect of the acoustic black hole. The gradient variation of the inner radius of the annular wave stop device is equivalent to a detuned vibration absorber. The resulting broadband low-frequency acoustic band gap and elastic band gap can effectively reduce shock tube noise and suppress structural vibration, while maintaining the aerodynamic performance and operating efficiency of the shock tube, and has strong operability.

[0021] 4. The gradient-designed shock tube vibration and noise reduction device for engineering use provided by the present invention has a simple method for regulating test parameters such as the vibration and noise frequency, amplitude, and direction of action caused by different high-speed shock waves during the test, and has a wide range of applications.

[0022] 5. The gradient-designed engineering shock tube vibration reduction and noise reduction device provided by the present invention is composed of a traditional engineering shock tube, an injection silencer and a simple vibration reduction and noise reduction device. It is cheap and has good economic benefits. All parts can be disassembled, and installation and replacement of test pieces are simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] Figure 1 is a front view of the device of the present invention;

[0025] Figure 2 It is a schematic cross-sectional view of the overall structure of the device of the present invention;

[0026] Figure 3 It is a three-dimensional schematic diagram of the overall structure of the device of the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of a cylindrical perforated exhaust column in the injection muffler module of the present invention;

[0028] Figure 5 It is a schematic diagram of the internal cross-section of the vibration reduction and noise reduction module structure of the present invention;

[0029] Figure 6 It is a schematic diagram of the overall structure of the injection silencer module of the present invention.

[0030] In the figure, 1- shock tube, 2- flange one, 3- left end flange, 4- cylindrical perforated exhaust column, 5- supporting ribs, 6- injection silencer module, 7- right end flange, 8- flange two, 9- test piece, 10- tube, 11- annular wave stop device, 12- rigid support ring, 13- cone-shaped hole. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of 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.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1 to 6 The present invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering use, comprising a shock tube 1, an injection silencer module 6, and a vibration reduction and noise reduction module 10.

[0034] The shock tube comprises a tube body 1 and a flange 2 at one end, wherein the flange 2 is coaxially fixed to the outer side of the shock tube 1 by welding.

[0035] The injection muffler module includes a plurality of cylindrical perforated exhaust columns 4 on the pipe wall of the injection muffler module, and the cylindrical perforated exhaust columns 4 are welded to the pipe body of the injection muffler module 6 .

[0036] The two ends of the pipe body of the injection silencer module 6 are respectively preset with a left end flange 3 and a right end flange 7 with high-strength bolt holes; one end of the injection silencer module 6 is coaxially fixed to the left end flange 3, and the other end of the injection silencer module 6 is coaxially fixed to the right end flange 7, and a number of supporting ribs 5 are evenly distributed along the injection silencer module 6 between the left end flange 3 and the right end flange 7.

[0037] The supporting ribs 5 and the cylindrical perforated exhaust columns are evenly spaced and arranged along the tube body of the injection silencer module 6. The supporting ribs 5 are welded to the left end flange 3 and the right end flange 7. The supporting ribs 5 and the tube body of the injection silencer module 6 are connected by welding; the flange 2 is connected to the left end flange 3 of the tube body of the injection silencer module 6 by high-strength bolts, and bolt pads are contained between the high-strength bolts.

[0038] The tube body of the injection silencer module 6 and the tube tube 10 of the vibration and noise reduction module have the same radius, and the test piece 9 is sandwiched between them.

[0039] The vibration and noise reduction module includes several annular wave stop devices 11 with changing inner radius inside the tube body of the vibration and noise reduction module. The annular wave stop devices 11 are connected to the tube body of the vibration and noise reduction module by welding. The inner radius of the annular wave stop devices 11 changes according to a power law function to achieve acoustic impedance adjustment. Rigid support rings 12 are arranged at intervals between the annular wave stop devices 11, and the rigid support rings 12 are welded to the tube body of the vibration and noise reduction module; one end of the vibration and noise reduction module is coaxially fixed to flange 8.

[0040] The left end flange 3 of the injection silencer module 6 is coaxially connected to the flange 1 2 of the shock tube 1 with high-strength bolts, and the right end flange 7 of the injection silencer module 6 is coaxially connected to the flange 2 8 of the vibration reduction and noise reduction module with high-strength bolts.

[0041] The right end flange 7 is coaxially connected to the flange 2 8 of the vibration reduction and noise reduction module through high-strength bolts, and a bolt pad is included between the high-strength bolts and the high-strength bolt holes.

[0042] Eight cylindrical perforated exhaust columns 4 are provided on the tube wall of the injection silencer module 6, and the cylindrical perforated exhaust columns 4 are welded to the tube body of the injection silencer module 6; a number of continuous through-going frustum-shaped holes 13 are provided in the cylindrical perforated exhaust columns 4; the large-diameter openings of the frustum-shaped holes 13 are sequentially facing the outside of the tube body; the frustum-shaped holes 13 are coaxial with the cylindrical perforated exhaust columns 4.

[0043] The test piece 9 is clamped between the right end flange 7 of the injection silencer module 6 and the left end flange 8 of the vibration reduction and noise reduction module. The right end flange 7, the left end flange 8 of the vibration reduction and noise reduction module and the test piece 9 are tightly connected by high-strength bolts, and each connection layer contains a thin rubber pad.

[0044] When in use, the high-pressure shock wave generated by the shock tube 1 impacts the test piece 9 to be tested. The shock wave after the test piece 9 is broken and decelerated passes through the cylindrical perforated exhaust column 4 of the injection silencer module 6, so as to achieve rapid weakening of the shock wave. When the decelerated shock wave passes through the vibration reduction and noise reduction module, the periodically arranged annular wave stop device 11 forms an acoustic black hole structure and produces a slow sound effect. The gradient change of its inner radius performs detuned vibration absorption to produce a broadband low-frequency acoustic band gap and an elastic band gap, which reduces the propagation speed of the shock wave and the reflection at the end of the boundary, so as to achieve rapid attenuation of the shock wave speed and rapid dispersion of energy, reduce large-scale vibration and increase acoustic impedance, and thus achieve the effect of improving vibration reduction and noise reduction performance.

[0045] The distance between the annular wave stop device 11 and the flange 8 is determined by the safe distance at which flying fragments may be generated after the test piece 9 is impacted by the shock wave. The debris cloud contours of the main test piece materials, concrete and steel, under the action of the shock wave are obtained through the shock tube test data, which can intuitively describe the overall flight form of the debris and perform formula fitting. When the debris cloud has a certain initial velocity, the influence of gravity on the contour morphology can be ignored, and the debris cloud contour is approximately centrally symmetric about the axis. After working condition statistics and least squares fitting, it is confirmed that the distance between the annular wave stop device 11 and the flange 8 can be a safe distance of more than 0.5m. The length of the injection silencer module tube body 6 is approximately 0.5m to 1.0m, which is the dominant wavelength of the shock tube, and the perforated exhaust column is arranged at a position corresponding to the midpoint of the axis of the injection silencer module tube body.

[0046] The inner radius of the annular wave stop device 11 decreases according to a power law function, and the wave stop devices are arranged equidistantly. This structure retains the slow sound effect of the acoustic black hole, and the non-uniformly distributed rings act as tuned vibration absorbers. Based on these characteristics, broadband low-frequency acoustic and elastic band gaps can be generated simultaneously.

[0047] The inner radius of the annular wave stop device follows a power law function:

[0048] r i =εx m +r0

[0049] Where r0 is a constant, ε is the first power law constant, m is the power law exponent, and x is the distance from the ring to the center point.

[0050] The slow sound effect of the acoustic black hole causes the wave speed to gradually decrease along the tube of the vibration and noise reduction module, so that the shock wave cannot reach the end of the structure and cannot be reflected. This effect is equivalent to the extension of the wavelength of the shock wave. By adjusting the gradient of the radius change of the annular wave stop device, that is, adjusting the ε value and the m value, the propagation characteristics of the shock wave in the vibration and noise reduction module can be changed.

[0051] Parameter analysis shows that as m increases, the acoustic band gap moves to the low-frequency region because the acoustic black hole slow sound effect is enhanced. In addition, by adjusting the number of rings n, the separated narrow band gaps can be merged into a wider band gap, thereby improving the effect of noise reduction. By precisely controlling the gradient of the inner radius of the annular wave stop device, the propagation path and speed of the shock wave can be effectively adjusted to achieve a low-frequency broadband acoustic band gap, thereby achieving the purpose of noise reduction.

[0052] An annular wave stop device 11 is provided in the vibration and noise reduction module, and its inner radius changes according to a power-law function to achieve acoustic impedance adjustment and form an acoustic black hole. It can effectively reduce the propagation speed of shock waves in the structure, reduce reflections at the end of the boundary, and form an area with high energy density. Therefore, it has broad application prospects in vibration reduction, noise reduction, wave regulation, and energy recovery.

[0053] The distance between the rings changes linearly, retaining the slow sound effect of the acoustic black hole. The non-uniformly distributed rings act as detuned vibration absorbers, while producing broadband low-frequency acoustic band gaps and elastic band gaps, which can effectively reduce airborne noise and suppress structural vibrations.

[0054] The vibration and noise reduction module composed of periodically arranged functional units has better physical properties of acoustic and elastic wave manipulation than traditional methods.

[0055] Band gap refers to the frequency band where sound waves and elastic waves cannot be transmitted through the medium. By controlling the position and width of the band gap, the gradient design method shows outstanding advantages over traditional methods in low-frequency sound and vibration insulation.

[0056] The acoustic black hole structure can generate both acoustic and vibration band gaps for multifunctional design. In addition, the non-uniformly distributed rings in the acoustic black hole structure are equivalent to detuned vibration absorbers, which widen the local resonance band gap due to the detuning effect.

[0057] On the pipe wall of the injection silencer module 6, eight perforated exhaust columns 4 are arranged around the pipe wall, and eight supporting ribs 5 are arranged around the pipe wall coaxially with the perforated exhaust columns 4, with the surrounding angle offset by 11.25°.

[0058] The perforated exhaust column 4 is made of high-strength steel, and the radius of the bottom of the frustum-shaped hole is not easy to be greater than 2 / 3 of the radius of the perforated exhaust column 4, and is not easy to be too small. Its advantages are that the device is simple and feasible, and the shock wave after the test piece 3 is broken can be quickly weakened by adjusting the hole radius. It is more suitable for high-pressure pipelines and variable load conditions, and replacement is also relatively simple.

[0059] An annular wave stop device 11 with periodic fixed spacing and gradient inner radius is provided inside the tube 10 of the vibration and noise reduction module. The propagation speed of the shock wave is reduced by forming an acoustic black hole, and the reflection at the end of the boundary is reduced, thereby reducing the aerodynamic noise and achieving rapid vibration and noise reduction. The size of the annular wave stop device 11 can be approximately determined based on the impact wavelength and wave speed. Considering the safety requirements, it should not be less than 2 / 3 times the thickness of the tube 10 of the vibration and noise reduction module; the inner radius change gradient of the annular wave stop device 11 should be selected between 10% and 15%.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A gradient design engineering shock tube vibration and noise reduction device, characterized in that: It includes a shock tube, an injection silencer module, and a vibration and noise reduction module; the shock tube is connected to the injection silencer module; the vibration and noise reduction module is connected to the injection silencer module; the shock tube, the injection silencer module and the vibration and noise reduction module are coaxially arranged.

2. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 1 is characterized in that: The injection silencer module is a pipe body with flanges at both ends; the pipe body is provided with a plurality of cylindrical perforated exhaust columns (4); a plurality of supporting ribs (5) are provided between the flanges at both ends of the pipe body; and the plurality of supporting ribs (5) are parallel to each other.

3. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 2 is characterized in that: A plurality of cylindrical perforated exhaust columns (4) are arranged in an annular pattern along the circumference of the tube body; a plurality of continuous through-going cone-shaped holes (13) are arranged in the cylindrical perforated exhaust column (4); the large diameter openings of the cone-shaped holes (13) are sequentially oriented toward the outside of the tube body; and a supporting rib plate (5) is provided between adjacent cylindrical perforated exhaust columns (4).

4. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 1 is characterized in that: The vibration reduction and noise reduction module comprises a tube (10), wherein an annular wave block device (11) is arranged inside the tube (10); the annular wave block device (11) is composed of a plurality of annular wave blocks, a noise reduction hole is arranged at the center of the annular wave block, and the inner radius of the plurality of noise reduction holes in the annular wave block device (11) changes in accordance with a power law function to achieve acoustic impedance adjustment.

5. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 4 is characterized in that: It also includes a rigid support ring (12); a rigid support ring (12) is arranged between every two adjacent annular wave stops in the annular wave stop device (11); and the rigid support ring (12) and the annular wave stops and the tube (10) in the annular wave stop device (11) are fixed to each other by welding.

6. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 4 is characterized in that: The inner diameters of the noise reduction holes of the plurality of annular wave block devices (11) decrease along the axial direction of the tube (10) from large to small, and then increase in sequence from small to large.

7. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 4 is characterized in that: The inner radius of the noise reduction hole follows the power law function expression as follows: r i =εx m +r0 Where r0 is a constant, ε is the first power law constant, m is the power law exponent, and x is the distance from the ring to the center point.

8. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 3 is characterized by: The major diameter of the frustum-shaped hole (13) inside the cylindrical perforated exhaust column (4) is smaller than the inner diameter of the cylindrical perforated exhaust column (4).

9. The gradient-designed shock tube vibration and noise reduction device for engineering use according to claim 3 or 8, characterized in that: The cylindrical perforated exhaust column (4) is made of high-strength steel, and the major diameter of the frustum-shaped hole is 2 / 3 of the cylindrical perforated exhaust column (4).

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