A gradient design type shock tube damping and noise reduction device for engineering

Abstract

The present application relates to the technical field of shock tube test device vibration reduction and noise reduction in the engineering anti-blast industry, and particularly relates to a gradient design type engineering shock tube vibration reduction and noise reduction device. The device comprises a shock tube, an injection noise elimination module and a vibration reduction and noise reduction module. The shock tube is connected to the injection noise elimination module. The vibration reduction and noise reduction module is connected to the injection noise elimination module. The shock tube, the injection noise elimination module and the vibration reduction and noise reduction module are coaxially arranged. The gradient design type engineering shock tube vibration reduction and noise reduction device provided by the present application optimizes airflow and sound wave propagation paths by gradient design, thereby effectively reducing 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 formed by periodically arranged functional units forms an acoustic black hole structure. Compared with traditional methods, the acoustic black hole structure has better acoustic and elastic wave control physical properties, can effectively reduce the propagation speed of the shock wave, and reduce the reflection at the boundary end.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction and noise reduction technology for shock tube testing devices in the engineering explosion-proof industry, specifically a gradient-designed engineering shock tube vibration reduction and noise reduction device. Background Technology

[0002] In modern engineering applications, shock tubes, as highly efficient gas dynamic devices, are widely used in aerospace, defense, and automotive fields to simulate phenomena such as high-speed airflow and explosive shock waves. However, because shock tubes generate strong sound waves and shock waves during operation, these waves not only interfere with the normal operation of the equipment but can also cause significant noise pollution to the surrounding environment. Therefore, how to effectively reduce vibration and noise has become an important research topic in shock tube technology. While several methods for vibration and noise reduction have been proposed in existing technologies, such as adding sound-absorbing materials inside the shock tube and using complex sound insulation structures, these methods generally suffer from low efficiency, large size, high cost, or negative impacts on the shock tube's performance. For example, traditional sound-absorbing materials often cannot operate stably for extended periods under high temperature and high pressure environments, leading to a decline in vibration reduction effectiveness. Furthermore, complex sound insulation structures not only increase the size and weight of the device but may also affect the aerodynamic performance of the shock tube, reducing its efficiency. In recent years, researchers have attempted to improve the vibration and noise reduction performance of shock tubes by modifying the internal flow structure and materials. For example, some progress has been made in controlling the propagation paths of sound waves and shock waves by introducing technologies such as porous media and flow control devices. However, these technologies are complex to implement, difficult to operate, and their adaptability and effectiveness remain limited for 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 shock tubes is a problem that urgently needs to be solved in the current technology field. Summary of the Invention

[0004] The purpose of this invention is to provide a gradient-designed vibration and noise reduction device for engineering shock tubes, which reduces the vibration and noise of engineering shock tubes under compressed air explosions. It can be used for vibration and noise control in large-scale indoor shock tube tests, and is highly operable. The method for adjusting test parameters such as frequency, amplitude, and direction of vibration and noise caused by different high-speed shock waves is simple, and it has a wide range of applications. It is composed of a traditional engineering shock tube, a jet silencing device, and a simple vibration and noise reduction device, making it inexpensive and economically efficient. All components are detachable, making installation and replacement of test specimens simple and convenient.

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

[0006] The present invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering applications, comprising a shock tube, a jet silencing module, and a vibration reduction and noise reduction module; the shock tube is connected to the jet silencing module; the vibration reduction and noise reduction module is connected to the jet silencing module; the shock tube, the jet silencing module, and the vibration reduction and noise reduction module are coaxially arranged.

[0007] The present invention discloses a gradient design shock tube vibration reduction and noise reduction device for engineering applications, wherein the injection silencing 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 support ribs are provided between the flanges at both ends of the tube body; the plurality of support ribs are parallel to each other.

[0008] The present invention discloses a gradient design shock tube vibration reduction and noise reduction device for engineering applications, wherein several cylindrical perforated exhaust columns are arranged at intervals along the circumference of the tube body; several continuously penetrating frustum-shaped holes are provided inside the cylindrical perforated exhaust columns; the large diameter openings of the frustum-shaped holes face the outer side of the tube body in sequence; and a support rib is provided between adjacent cylindrical perforated exhaust columns.

[0009] The present invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering applications. The vibration reduction and noise reduction module includes a tube, and an annular wave-damping device is provided inside the tube. The annular wave-damping device is composed of several annular wave-dams, and a noise reduction hole is provided at the center of the annular wave-dams. The inner radius of the several noise reduction holes in the annular wave-damping device changes according to a power law function to achieve acoustic impedance adjustment.

[0010] The gradient design engineering shock tube vibration reduction and noise reduction device of the present invention further includes a rigid support ring; a rigid support ring is arranged between every two adjacent annular corrugations in the annular corrugation device; the rigid support ring is fixed to the annular corrugations and the tube in the annular corrugation device by welding.

[0011] The present invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering applications, wherein the inner diameter of the noise reduction holes of the plurality of annular wave-damping devices decreases from large to small along the axial direction of the tube and then increases sequentially from small to large.

[0012] The gradient-designed shock tube vibration reduction and noise reduction device for engineering applications described in this invention has an inner radius of the noise reduction hole that varies according to a power-law function, as expressed in the following formula:

[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 present invention discloses a gradient-designed shock tube vibration reduction and noise reduction device for engineering applications, wherein the large diameter of the frustum-shaped hole inside the cylindrical perforated exhaust column is smaller than the inner diameter of the cylindrical perforated exhaust column.

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

[0017] The beneficial effects of this invention are:

[0018] 1. The gradient-designed shock tube vibration reduction and noise reduction device provided by this invention optimizes the airflow and sound wave propagation paths through gradient design, 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 characteristics 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 design engineering shock tube vibration reduction and noise reduction device provided by the present invention has a spray silencing module with a shock wave section to reduce the peak pressure of the shock wave, reduce the shock wave to within a safe range and suppress the airflow from forming a circumferential flow at the pipe opening.

[0020] 3. The gradient-designed shock tube vibration reduction and noise reduction device for engineering applications provided by this invention features a linearly varying spacing between the annular wave-damping devices of the vibration reduction and noise reduction module, which preserves the slow-motion effect of the acoustic black hole. The gradient change of the inner radius of the annular wave-damping device is equivalent to a detuned vibration absorber. The resulting broadband low-frequency acoustic bandgap and elastic bandgap can effectively reduce shock tube noise and suppress structural vibration, while maintaining the aerodynamic performance and operating efficiency of the shock tube, and is highly operable.

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

[0022] 5. The gradient design engineering shock tube vibration reduction and noise reduction device provided by the present invention is composed of a traditional engineering shock tube, a jet silencing device and a simple vibration reduction and noise reduction device. It is inexpensive and has good economic benefits. All components can be disassembled, and the installation and replacement of test specimens are simple and convenient. Attached Figure Description

[0023] The invention will now be further described with reference to the accompanying drawings.

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

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

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

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

[0028] Figure 5 This 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 This is a schematic diagram of the overall structure of the injection silencing 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-support rib, 6-jetting silencer module, 7-right end flange, 8-flange two, 9-test piece, 10-tube, 11-annular wave baffle device, 12-rigid support ring, 13-frustum-shaped hole. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be 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 design shock tube vibration reduction and noise reduction device for engineering applications, including a shock tube 1, a jet silencing module 6, and a vibration reduction and noise reduction module 10.

[0034] The shock tube includes a tube body 1 and a flange 2 at one end, which is coaxially fixed to the outside of the shock tube 1 by welding.

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

[0036] The two ends of the pipe body of the injection silencing module 6 are respectively pre-set with a left flange 3 and a right flange 7 with high-strength bolt holes; one end of the injection silencing module 6 is coaxially fixed to the left flange 3, and the other end of the injection silencing module 6 is coaxially fixed to the right flange 7. Several support ribs 5 are evenly distributed around the injection silencing module 6 between the left flange 3 and the right flange 7.

[0037] Support ribs 5 and cylindrical perforated exhaust columns are evenly spaced around the pipe body of the injection silencing module 6. Support ribs 5 are welded to the left flange 3 and the right flange 7. Support ribs 5 are welded to the pipe body of the injection silencing module 6. Flange 2 is connected to the left flange 3 of the pipe body of the injection silencing module 6 by high-strength bolts, and bolt pads are contained between the high-strength bolts.

[0038] The tube body of the injection silencing module 6 has the same radius as the tube 10 of the vibration reduction and noise reduction module, with the test piece 9 sandwiched in the middle.

[0039] The vibration reduction and noise reduction module includes several annular wave-damping devices 11 with varying inner radii inside the module tube. The annular wave-damping devices 11 are welded to the module tube. The inner radius of the annular wave-damping devices 11 varies according to a power law function to achieve acoustic impedance adjustment. Rigid support rings 12 are arranged at intervals between the annular wave-damping devices 11. The rigid support rings 12 are welded to the module tube. One end of the vibration reduction and noise reduction module is coaxially fixed to a flange 8.

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

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

[0042] The injection silencer module 6 has 8 cylindrical perforated exhaust columns 4 on its pipe wall, which are welded to the pipe body of the injection silencer module 6. The cylindrical perforated exhaust columns 4 have several continuous frustum-shaped holes 13 inside. The large diameter openings of the frustum-shaped holes 13 face the outside of the pipe body in sequence. The frustum-shaped holes 13 are coaxial with the cylindrical perforated exhaust columns 4.

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

[0044] In use, the high-pressure shock wave generated by the shock tube 1 impacts the test specimen 9. After the test specimen 9 breaks and decelerates, the shock wave passes through the cylindrical perforated exhaust column 4 of the injection silencing module 6, which can quickly weaken the shock wave. When the decelerated shock wave passes through the vibration reduction and noise reduction module, the periodically arranged annular wave-blocking device 11 forms an acoustic black hole structure and produces a slow sound effect. The gradient change of its inner radius causes detuning and vibration absorption, generating a broadband low-frequency acoustic bandgap and an elastic bandgap, reducing the propagation speed of the shock wave and reducing the reflection at the boundary end. This can achieve rapid attenuation of the shock wave velocity and rapid dispersion of energy, thereby reducing a large range of vibrations and increasing acoustic impedance, and thus achieving the effect of improving vibration reduction and noise reduction performance.

[0045] The distance between the annular wave-damping device 11 and flange 8 is determined by the safe distance that the test specimen 9 may generate after being impacted by the shock wave. The debris cloud profiles of the main specimen materials, concrete and steel, under the action of the shock wave are obtained through shock tube test data, which can intuitively describe the overall flight morphology of the debris and perform formula fitting. When the debris cloud has a certain initial velocity, the influence of gravity on the profile morphology is negligible, and the debris cloud profile is approximately centrally symmetric about the axis. Through statistical analysis of operating conditions and least squares fitting, it is confirmed that the distance between the annular wave-damping device 11 and flange 8 can be a safe distance of 0.5m or more. The length of the injection silencing module tube 6 is approximately taken as 0.5m to 1.0m of the dominant wavelength of the shock tube, and the perforated exhaust column is arranged at the position corresponding to the midpoint of the axis of the injection silencing module tube.

[0046] The inner radius of the annular beambearing device 11 decreases according to a power-law function, and the beambearing devices are arranged at equal intervals. This structure preserves the slow-motion effect of acoustic black holes, and the non-uniformly distributed rings act as tuned resonant vibration absorbers. Based on these characteristics, broadband low-frequency acoustic and elastic bandgap can be generated simultaneously.

[0047] The inner radius of the annular wave-damping device varies according to 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-motion effect of an acoustic black hole causes the wave velocity to gradually decrease along the tube of the vibration damping and noise reduction module, preventing the shock wave from reaching the end of the structure and thus preventing reflection. This effect is equivalent to extending the shock wave wavelength. By adjusting the gradient of the inner radius of the annular wave-damping device, i.e., adjusting the ε and m values, the propagation characteristics of the shock wave in the vibration damping and noise reduction module can be changed.

[0051] Parametric analysis shows that as m increases, the acoustic bandgap shifts towards the low-frequency region due to the enhanced slow-motion effect of the acoustic black hole. Furthermore, by adjusting the number of rings n, separated narrow bandgapes can be merged into a wider bandgap, thereby improving noise reduction. By precisely controlling the gradient of the inner radius of the annular wave-damping device, the propagation path and velocity of the shock wave can be effectively adjusted, achieving a low-frequency broadband acoustic bandgap and thus achieving noise reduction.

[0052] The vibration reduction and noise reduction module is equipped with an annular wave-damping device 11. Its inner radius changes according to a power law function to achieve acoustic impedance adjustment and form an acoustic black hole. This can effectively reduce the propagation speed of shock waves in the structure, reduce reflection at the boundary end, and form a region with high energy density. Therefore, it has broad application prospects in vibration reduction, noise reduction, wave control, and energy recovery.

[0053] The distance between the rings varies linearly, preserving the slow-motion effect of the acoustic black hole. The non-uniformly distributed rings act as detuned vibration absorbers, while simultaneously generating broadband low-frequency acoustic bandgap and elastic bandgap, which can effectively reduce airborne noise and suppress structural vibration.

[0054] The vibration reduction and noise reduction module, which is composed of periodically arranged functional units, has better acoustic and elastic wave control physical characteristics compared with traditional methods.

[0055] A bandgap is a frequency band in which sound waves and elastic waves cannot propagate through a medium. By controlling the position and width of the bandgap, the gradient design method shows significant advantages over traditional methods in low-frequency sound insulation and vibration control.

[0056] Acoustic black hole structures can simultaneously generate acoustic and vibrational band gaps, enabling multifunctional designs. Furthermore, the non-uniformly distributed rings in the acoustic black hole structure are equivalent to detuned vibration absorbers, and the detuning effect widens the local resonant band gap.

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

[0058] The perforated vent column 4 is made of high-strength steel. The radius of the bottom of the frustum-shaped hole should not be greater than 2 / 3 of the radius of the perforated vent column 4, and should not be too small. Its advantage is 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] The tube 10 of the vibration reduction and noise reduction module is equipped with a periodically spaced, gradient-inner-radius-variing annular wave-damping device 11. This device reduces the propagation speed of the shock wave by forming an acoustic black hole, thereby reducing reflection at the boundary end and weakening aerodynamic noise to achieve rapid vibration reduction and noise reduction. The dimensions of the annular wave-damping device 11 can be approximately determined based on the impact wavelength and wave velocity. Considering safety requirements, it should not be less than 2 / 3 times the thickness of the tube 10 of the vibration reduction and noise reduction module. The gradient of the inner radius of the annular wave-damping device 11 should preferably be selected between 10% and 15%.

[0060] The foregoing has shown and described 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. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A gradient-designed shock tube vibration reduction and noise reduction device for engineering applications, characterized in that: It includes a shock tube, a jet silencing module, and a vibration reduction and noise reduction module; the shock tube is connected to the jet silencing module; the vibration reduction and noise reduction module is connected to the jet silencing module; the shock tube, the jet silencing module, and the vibration reduction and noise reduction module are arranged coaxially. The injection silencer module is a pipe with flanges at both ends; the pipe is provided with several cylindrical perforated exhaust columns (4); several support ribs (5) are provided between the flanges at both ends of the pipe; the several support ribs (5) are parallel to each other. Several cylindrical perforated exhaust columns (4) are arranged at intervals around the circumference of the pipe body; several continuous frustum-shaped holes (13) are provided inside the cylindrical perforated exhaust columns (4); the large diameter openings of the frustum-shaped holes (13) face the outside of the pipe body in sequence; a support rib (5) is provided between adjacent cylindrical perforated exhaust columns (4). The vibration reduction and noise reduction module includes a tube (10), which is equipped with an annular wave-damping device (11). The annular wave-damping device (11) is composed of several annular waves, and a noise reduction hole is provided at the center of the annular waves. The inner radius of the several noise reduction holes in the annular wave-damping device (11) changes according to a power law function to achieve acoustic impedance adjustment.

2. The gradient-designed engineering shock tube vibration reduction and noise reduction device according to claim 1, characterized in that: It also includes a rigid support ring (12); a rigid support ring (12) is arranged between every two adjacent annular corrugations in the annular corrugation device (11); the rigid support ring (12) is fixed to the annular corrugations and the tube (10) in the annular corrugation device (11) by welding.

3. The gradient-designed engineering shock tube vibration reduction and noise reduction device according to claim 1, characterized in that: The inner diameter of the noise reduction holes of several annular wave-damping devices (11) decreases from large to small along the axial direction of the tube (10), and then increases from small to large.

4. The gradient-designed engineering shock tube vibration reduction and noise reduction device according to claim 1, characterized in that: The expression for the inner radius of the noise reduction aperture following a power-law function is 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.

5. The gradient-designed engineering shock tube vibration reduction and noise reduction device according to claim 1, characterized in that: The large 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).

6. The gradient-designed engineering shock tube vibration reduction and noise reduction device according to claim 5, characterized in that: The cylindrical perforated exhaust column (4) is made of high-strength steel, and the large diameter of the frustum-shaped hole is 2 / 3 of that of the cylindrical perforated exhaust column (4).

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