Groove scale unit with micro-spring tension structure as substrate and resistance-reducing, noise-suppressing and noise-eliminating covering layer

Abstract

The invention discloses a groove scale unit with a micro-spring tension structure as a substrate and a damping, noise-suppressing and noise-eliminating covering layer. The groove scale unit is formed by connecting and arranging a plurality of groove scale units of the micro-spring tension structure substrate end to end according to a rhombic array. Each groove scale unit with the micro-spring tension structure substrate comprises a groove scale, an upper platform, a connecting hinge, a local resonance rod, a local vibrator, a spring and a lower platform. The groove scales are fixed to the upper end face of the upper platform, the longitudinally-arranged local resonance rods are fixed to the upper platform and the lower platform through connecting hinges respectively, one ends of the transversely-arranged local resonance rods are fixed to the lower platform through hinges, and the other ends of the transversely-arranged local resonance rods are connected with the upper platform and the lower platform through springs. The device can well simulate the process that low-speed vortex is generated at the tail of the scale to inhibit generation of turbulent flow in the swimming process of cyprinid fishes, so that fluid resistance and hydrodynamic noise are reduced. The micro-spring tensioning structure has the good multi-dimensional vibration absorption characteristic, and vibration noise transmission inside and outside the covering layer can be effectively weakened.

Description

Technical Field

[0001] The invention belongs to the field of mechanical engineering, and in particular relates to a groove scale unit based on a micro-spring tensioning structure and a drag-reducing, noise-suppressing and sound-absorbing covering layer. Background Art

[0002] Improving the drag reduction, noise suppression and silencing performance is crucial to improving the speed and endurance of underwater vehicles and improving their acoustic stealth capabilities. With the development of science and technology, higher requirements are placed on the drag reduction, noise suppression and silencing performance of underwater vehicles. How to improve the drag reduction, noise suppression and silencing performance of underwater vehicles has become a research hotspot in the field of ship machinery design and manufacturing.

[0003] The unique biological structures and functions of some aquatic organisms in nature enable them to swim quickly and quietly, which provides inspiration for people to achieve fluid drag reduction and noise suppression. Among them, the skin of carp fish exhibits excellent drag reduction performance due to the orderly arrangement of grooved scales on the surface, and has become an important object of bionic drag reduction and noise suppression research. The groove structure on the surface of the scales can directly affect and improve the characteristic structural distribution of the turbulent boundary layer flow field. Combined with the vibration absorption and buffering characteristics of the skin at the bottom of the scales, it can inhibit the generation and development of turbulence, thereby effectively reducing the fluid resistance and hydrodynamic noise during swimming, allowing fish to swim quickly and quietly. Therefore, the researchers tried to design a grooved drag reduction structure based on fish skin, and applied it to the surface of underwater vehicles, so that it not only has the function of drag reduction but also has the function of noise suppression and silencing, thereby improving the stealth capability of underwater vehicles. Summary of the invention

[0004] The purpose of the present invention is to provide a grooved scale unit and a drag reduction, noise suppression and sound absorbing covering layer based on a micro-spring tensioning structure, which can reduce the fluid resistance experienced by an underwater vehicle, the flow-induced noise generated by hydrodynamic excitation, and the noise transmission inside and outside the vehicle cabin.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A groove scale unit with a micro-spring tension structure as a base comprises a groove scale, an upper platform, an upper connecting hinge, a local resonance rod, a local vibrator, a micro-spring, a lower connecting hinge and a lower platform; the groove scale is fixed to the upper end surface of the upper platform; the lower end surface of the upper platform is evenly provided with a plurality of upper connecting hinges around its central axis; the upper end surface of the lower platform is provided with three lower connecting hinges around its central axis; each lower connecting hinge comprises a long connecting hinge and a short connecting hinge; the vertical axis of each upper connecting hinge is The direct projections are all located within the circle surrounded by the long connecting hinge and the short connecting hinge; the local oscillators are evenly fixed on the local resonant rods; the local resonant rods are connected by micro springs; the two ends of the longitudinally arranged local resonant rods are respectively fixed to the adjacent upper connecting hinges and short connecting hinges; one end of the transversely arranged local resonant rod is fixed to the long connecting hinge, and the other end is suspended, and the suspended end is respectively connected to the long connecting hinge below the suspended end, the short connecting hinge and the upper connecting hinge at the lower end of the upper platform through three micro springs.

[0007] Furthermore, the grooved scales are modeled after the surface morphology of carp scales, and each side of the grooved scales is an arc of equal radius.

[0008] Furthermore, the groove scales are made of organic polymer material.

[0009] Furthermore, each upper connecting hinge is equidistant from the central axis of the upper platform.

[0010] Furthermore, each of the long connecting hinges and the short connecting hinges is equidistant from the central axis of the lower platform.

[0011] Furthermore, the circle formed by the upper connecting hinge and the circle formed by the lower connecting hinge are concentric circles.

[0012] Furthermore, three nodes are equidistantly taken from the middle part of the local resonance rod to fix the rubber vibration-damping ring of the local oscillator, and the steel shell of the local oscillator is fixed outside the rubber vibration-damping ring.

[0013] Furthermore, the mass of the rubber vibration damping ring in the single local vibrator is 1.2 grams, and the mass of the local vibrator metal ring is 9 grams.

[0014] A grooved scale drag reduction, noise suppression and sound absorbing covering layer based on a micro-spring tensioning structure comprises a plurality of grooved scale units based on the micro-spring tensioning structure, wherein the grooved scale units are arranged in a rhombus array and fixed on an underwater vehicle shell.

[0015] Furthermore, the stiffness range of the single microspring is 0-200 (N / m), and the damping range is 0-0.08.

[0016] Furthermore, when the grooved scale drag reduction, noise suppression and sound-absorbing covering layer is working, a low-speed vortex in the clockwise direction appears at the rear of the grooved scale, and the fluid is gradually lifted through the scale unit and reaches the highest point at the outer edge of the grooved scale. The periodic wall oscillation will cause the longitudinal vorticity to decrease, and the up and down fluctuating streamlines control the generation and development of turbulence, thereby reducing the fluid resistance encountered by the underwater vehicle during navigation.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention can well simulate the morphology and movement characteristics of fish skin in nature. In the flow field, the tail of each groove scale arranged in an array will generate a low-speed vortex, which can inhibit the external fluid from entering the groove, keep the high-speed flow away from the near-wall area, effectively reduce the near-wall speed, inhibit the generation and development of turbulence, and thus reduce fluid resistance and hydrodynamic noise. In addition, the micro-spring tensioning structure of the substrate will deform and move under the action of hydrodynamic excitation, which can simulate the multi-dimensional movement of fish scales, so that the covering layer can better adapt to the flow field changes, thereby further improving its drag reduction performance.

[0019] 2. The grooved scale covering layer with the micro-spring tensioning structure as the base in the present invention is a regular tetrahedron tensioning structure with micro-springs. The local vibrator in the structure is composed of a rubber vibration-damping ring and a metal shell. When in motion, the rubber vibration-damping ring drives the metal shell to form an additional mass block, which can absorb the energy from the grooved scales and has a good attenuation effect on the vibration elastic waves generated by hydrodynamic excitation, thereby effectively weakening the vibration and realizing the noise suppression function. In addition, the microspring stiffness, damping and other parameters used in the grooved scale covering layer with the micro-spring tensioning structure as the base in the present invention can be selected according to the actual use environment to obtain a covering layer with a specific effect, which has a good adaptability to the use environment, so that the noise suppression and silencing function can be better realized.

[0020] 3. The micro-spring tensioning structure in the present invention is a semi-enclosed space formed by the grooved scale covering layer of the base arranged in a diamond array, which can form a stable and continuous liquid film, converting the solid-liquid contact formed by the turbulence and the covering layer into a liquid-liquid contact between the turbulence and the liquid film, playing the role of fluid lubrication, reducing the noise generated by friction, and realizing the muffler function. In addition, the acoustic properties of the material used in the present invention can well suppress the transmission of internal and external noise of the underwater vehicle, thereby realizing the acoustic stealth function. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 yes Figure 1 Schematic diagram of a grooved scale sound-absorbing covering layer unit with a micro-spring tension structure as the base;

[0023] Figure 3 yes Figure 2 Schematic diagram of the relative positions of the spring, local resonance rod, and local oscillator in the central tetrahedron spring tension structure;

[0024] Figure 4 yes Figure 2 A magnified image of a single local resonant rod;

[0025] Figure 5 This is a partial enlarged view of the A part of the groove scale covering layer unit with the micro spring tension structure as the base of the present invention

[0026] Figure 6 This is an enlarged view of the grooved scale of the present invention

[0027] Figure 7 is a streamline diagram of the scale surface of the present invention;

[0028] Figure 8 This is a schematic diagram of the drag reduction characteristics of the grooved scale covering layer based on the micro-spring tensioning structure of the present invention.

[0029] Fig. 9 Schematic diagram of the noise reduction characteristics of the present invention

[0030] Description of Figure Numbers:

[0031] 1. Grooved scale unit; 2. Underwater vehicle shell; 3. Grooved scale; 4. Upper platform; 5. Upper connecting hinge; 6. Microspring; 7. Local resonant rod; 8. Local oscillator; 8a. Rubber vibration damping ring; 8b. Metal ring; 9. Lower connecting hinge; 9a. Long connecting hinge; 9b. Short connecting hinge; 10. Lower platform; 11. Scale surface streamline; 12. Low-speed vortex; 13. Hydrodynamic noise; 14. External noise; 15. Cabin internal noise; 16. Grooved scale drag reduction, noise suppression and sound-absorbing covering layer. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings.

[0033] In order to imitate the vibration absorption and buffering characteristics of fish skin, the present invention designs a groove scale drag reduction, noise suppression and sound elimination covering layer based on a microspring tensioning structure. The microspring tensioning mechanism is a new type of noise suppression mechanism, in which the upper platform connected by the microspring and the local resonance rod can imitate the multi-dimensional movement form of fish skin, and has a strong attenuation effect on the vibration elastic wave, thereby effectively weakening the excitation and shell vibration caused by turbulence on its surface, thereby realizing the fluid noise reduction function. In addition, the local oscillator of the local resonance rod that constitutes the tensioning structure can effectively absorb vibration energy and generate a vibration wave band gap, thereby further weakening and suppressing vibration transmission, playing a role in vibration reduction and sound elimination.

[0034] like Figure 1 As shown, the grooved scale drag reduction, noise suppression and sound elimination covering layer with a micro-spring tension structure as the base of the present invention comprises a plurality of micro-spring tension structure grooved scale units 1. The plurality of micro-spring tension structure grooved scale units 1 are arranged in a diamond array and fixed on the underwater vehicle shell 2 to form a covering layer with drag reduction, noise suppression and sound elimination functions.

[0035] Combination Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 , the groove scale unit 1 of the micro-spring tension structure is described in detail: the groove scale unit 1 of the micro-spring tension structure includes a groove scale 3, an upper platform 4, 3 upper connecting hinges 5, 18 springs 6, 6 local resonance rods 7, 18 local oscillators 8, 3 lower connecting hinges 9 and a lower platform 10; the groove scale 3 is made of polyurethane material and fixed to the upper end face of the upper platform 4 by strong glue. Each side of the groove scale is an arc of equal radius, which ensures that the groove scale 3 can reconstruct the groove scale diamond array structure to the maximum extent after being arranged in a diamond array. Three upper connecting hinges 5 are fixed at the concentric circle of the lower end face of the upper platform 4 by strong glue, and each upper connecting hinge 5 is equidistant from the central axis of the upper platform 4. Three long connecting hinges 9a and three short connecting hinges 9b are fixed at the same center of the upper end surface of the lower platform 10 by strong glue, and each long connecting hinge 9a and short connecting hinge 9b is equidistant from the central axis of the lower platform 10. The vertical projection of the circle formed by each pair of upper connecting hinges 5 is located in the middle of the circle formed by the lower connecting hinges. The two ends of the longitudinally arranged local resonance rod 7 are respectively fixed to the adjacent upper connecting hinges 5 and short connecting hinges 9b. One end of the transversely arranged local resonance rod 7 is fixed to the long connecting hinge 9a, and the other end is suspended. The suspended end is respectively connected to the long connecting hinge 9a, the short connecting hinge 9b and the upper connecting hinge 5 at the lower end of the upper platform 4 below the suspended end through three micro springs 6. The spring 6 is connected to the local resonance rod 7 by welding. The rubber vibration damping ring 8a of the local oscillator is fixed at three nodes in the middle part of the local resonance rod 7, and the steel shell 8b of the local oscillator is fixed to the outside of the rubber vibration damping ring 8a of the local oscillator by glue. The two ends of the local resonance rod 7 are fixedly connected to the adjacent upper connecting hinge 5 and the lower connecting hinge 9 by strong glue, forming Figure 2 The micro-spring tension structure groove scale unit 1 is shown.

[0036] Combination Figure 7 and Figure 8, the drag reduction and noise reduction characteristics of the present invention are explained: the groove scale rhombus array drag reduction, noise suppression and noise reduction covering layer 16 based on the micro-spring tensioning structure is fixed on the surface of the underwater vehicle shell 2. During the flow process, a low-speed vortex 12 appears in the clockwise direction at the rear of the groove scale 3, which can inhibit the external fluid from entering the groove, keep the high-speed flow away from the near-wall area, effectively reduce the near-wall speed, and greatly weaken the turbulence. Due to the existence of the low-speed vortex 12, the fluid is gradually lifted through the scale unit and reaches the highest point at the outer edge of the scale. The periodic wall oscillation will lead to a decrease in longitudinal vorticity. The up and down fluctuating streamlines 11 can control the generation and development of turbulence, thereby reducing the fluid resistance encountered by the underwater vehicle during navigation. In addition, the semi-enclosed space formed by the groove scale covering layer with the micro-spring tensioning structure as the base is arranged in a rhombus array, which can form a stable and continuous liquid film, converting the solid-liquid contact formed by the turbulence and the covering layer into a liquid-liquid contact between the turbulence and the liquid film, playing the role of fluid lubrication, reducing the noise generated by friction, and realizing the noise reduction function.

[0037] Combination Fig. 9 , the noise suppression characteristics of the present invention are explained: the grooved scale covering layer 16 with the micro-spring tensioning structure as the base is a regular tetrahedron tensioning structure with micro-springs. When the local vibrator 8 in the structure moves, the metal shell is driven by the rubber vibration reduction ring to form an additional mass block, which can absorb the energy from the grooved scales, and has a good attenuation effect on the vibration elastic waves generated by the external noise 14, thereby effectively weakening the vibration and realizing the noise suppression function. The grooved scale diamond array drag reduction, noise suppression and sound absorbing covering layer 16 based on the micro-spring tensioning structure is fixed on the surface of the underwater vehicle shell 2. The unique periodic structure formed by the covering layer and the acoustic characteristics of the material composition can suppress the reflection and transmission of the external noise 14 and the internal noise 15 of the cabin, thereby achieving the effect of noise suppression.

[0038] Among them, the relevant structural parameters (microspring stiffness, damping and local oscillator mass, etc.) of the groove scale unit 1 of the microspring tensioning structure of the present invention can be formulated according to the actual use environment. For example, reducing the local oscillator mass can improve the noise suppression effect of the structure, and increasing the microspring stiffness or increasing the microspring damping can improve the drag reduction effect of the structure, thereby obtaining a covering layer with a specific effect, which has good adaptability to the use environment and can better realize the drag reduction and noise suppression functions of the structure.

[0039] In summary, the present invention is a reconstruction of the grooved scale diamond array structure of the micro-spring tensioning structure, which can realize the multi-dimensional movement of the scales in the flow field, thereby responding to the resistance formed by hydrodynamic excitation, reducing the fluid resistance on the surface of the underwater vehicle and the vibration noise generated by the vehicle, and improving the structural stealth performance.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A groove scale unit based on a micro-spring tension structure, characterized in that: The invention comprises a groove scale (3), an upper platform (4), an upper connecting hinge (5), a local resonance rod (7), a local oscillator (8), a micro spring (6), a lower connecting hinge (9) and a lower platform (10); the groove scale (3) is fixed to the upper end surface of the upper platform (4); a plurality of upper connecting hinges (5) are evenly arranged on the lower end surface of the upper platform (4) around its central axis; three lower connecting hinges (9) are arranged on the upper end surface of the lower platform (10) around its central axis; each lower connecting hinge (9) comprises a long connecting hinge (9a) and a short connecting hinge (9b); the vertical projection of each upper connecting hinge (5) is located at the long connecting hinge (9a) and the short connecting hinge (9b). The local oscillator (8) is evenly fixed on the local resonance rod (7); the local resonance rods (7) are connected by micro springs (6); the two ends of the longitudinally arranged local resonance rod (7) are respectively fixed to the adjacent upper connection hinge (5) and the short connection hinge (9b); one end of the transversely arranged local resonance rod (7) is fixed to the long connection hinge (9a), and the other end is suspended, and the suspended end is respectively connected to the long connection hinge (9a) below the suspended end, the short connection hinge (9b) and the upper connection hinge (5) at the lower end of the upper platform (4) through three micro springs (6).

2. A groove scale unit based on a micro-spring tensioning structure according to claim 1, characterized in that: The grooved scales (3) are modeled after the surface morphology of scales of carp fish, and each side of the grooved scales (3) is an arc of equal radius.

3. The groove scale unit based on the micro-spring tension structure according to claim 2, characterized in that: The groove scales (3) are made of organic polymer material.

4. The groove scale unit based on the micro-spring tension structure according to claim 1, characterized in that: The distances between each upper connecting hinge (5) and the central axis of the upper platform (4) are equal.

5. The groove scale unit based on the micro-spring tension structure according to claim 1, characterized in that: The distances between each long connecting hinge (9a) and each short connecting hinge (9b) and the central axis of the lower platform (10) are equal.

6. The groove scale unit based on the micro-spring tension structure according to claim 1, characterized in that: The circle formed by the upper connecting hinge (5) and the circle formed by the lower connecting hinge (9) are concentric circles.

7. The groove scale unit based on the micro-spring tension structure according to claim 1, characterized in that: A plurality of nodes are taken from the middle part of the local resonance rod (7) to fix the rubber vibration damping ring (8a) of the local oscillator (8), and the steel shell (8b) of the local oscillator is fixed outside the rubber vibration damping ring (8a).

8. A grooved scale drag reduction, noise suppression and sound absorbing covering layer based on a micro-spring tensioning structure, characterized in that: It comprises a plurality of groove scale units (1) as described in any one of claims 1 to 8, wherein the groove scale units (1) with the plurality of micro-spring tensioning structures as the base are arranged in a rhombus array and fixed on the underwater vehicle shell (2).

9. The grooved scale drag reduction, noise suppression and sound absorbing covering layer based on a micro-spring tensioning structure according to claim 8, characterized in that: When the grooved scale drag reduction, noise suppression and sound absorbing covering layer (16) is in operation, a low-speed vortex (12) in a clockwise direction appears at the rear of the grooved scale (3), and the fluid is gradually lifted through the scale unit, reaching the highest point at the outer edge of the grooved scale (3). The periodic wall oscillation will lead to a reduction in longitudinal vorticity, and the up and down fluctuating streamlines (11) control the generation and development of turbulence, thereby reducing the fluid resistance encountered by the underwater vehicle during navigation.

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