A grooved scale unit based on a micro-spring tensioning structure and a drag-reducing, noise-suppressing and sound-absorbing covering layer

Abstract

The present invention discloses a grooved scale unit and a drag-reducing, noise-suppressing and sound-absorbing covering layer based on a micro-spring tensioning structure, which is composed of a plurality of grooved scale units based on a micro-spring tensioning structure arranged end to end in a diamond array. The grooved scale unit based on the micro-spring tensioning structure includes a grooved scale, an upper platform, a connecting hinge, a local resonance rod, a local oscillator, a spring and a lower platform. The grooved scale is fixed to the upper end face of the upper platform, the longitudinally arranged local resonance rod is fixed to the upper and lower platforms respectively by a connecting hinge, and one end of the transversely arranged local resonance rod is fixed to the lower platform by a hinge, and the other end is connected to the upper and lower platforms by a spring. The present invention can well simulate the process of the scale tail generating low-speed vortices to suppress turbulence during the swimming process of carp fish, thereby reducing fluid resistance and hydrodynamic noise. The micro-spring tensioning structure has good multi-dimensional vibration absorption characteristics, which can effectively weaken the transmission of vibration noise inside and outside the covering layer.

Description

Technical Field

[0001] The present 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 drag reduction, noise suppression, and anechoic performance is crucial for improving the speed and endurance of underwater vehicles, as well as enhancing their acoustic stealth capabilities. With the advancement of science and technology, higher requirements are being placed on the drag reduction, noise suppression, and anechoic performance of underwater vehicles. Improving these performance has become a research hotspot in the field of marine machinery design and manufacturing.

[0003] The unique biological structures and functions of certain 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, making it 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 properties of the skin at the bottom of the scales, it can inhibit the generation and development of turbulence, thereby effectively reducing fluid resistance and hydrodynamic noise during swimming, allowing fish to swim quickly and quietly. Therefore, researchers tried to design a grooved drag reduction structure based on fish skin and apply 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-reducing, noise-suppressing and sound-absorbing covering layer based on a micro-spring tensioning structure, which can reduce the fluid resistance experienced by underwater vehicles, 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 based on a micro-spring tensioning structure comprises a groove scale, an upper platform, an upper connecting hinge, a local resonance rod, a local oscillator, 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 straight 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 microsprings; 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 in the air, 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 microsprings.

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

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

[0009] Furthermore, the distance between each upper connecting hinge and the central axis of the upper platform is equal.

[0010] Furthermore, the distances from each long connecting hinge and short connecting hinge to the central axis of the lower platform are equal.

[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 absorption covering layer based on a micro-spring tensioning structure comprises a plurality of grooved scale units based on the micro-spring tensioning structure. The grooved scale units are arranged in a rhombus array and fixed on the 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 lead to a decrease in longitudinal vorticity, 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. This invention effectively simulates the morphology and movement characteristics of natural fish skin. In the flow field, the tail of each array of connected grooved scales generates low-speed vortices, which inhibit external fluid from entering the grooves and direct high-speed flow away from the near-wall area, effectively reducing near-wall velocity and inhibiting the generation and development of turbulence, thereby reducing fluid resistance and hydrodynamic noise. Furthermore, the microspring tensioning structure of the base deforms and moves under hydrodynamic excitation, simulating the multi-dimensional motion of fish scales. This allows the cover layer to better adapt to changes in the flow field, further enhancing its drag reduction performance.

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

[0020] 3. The microspring tensioning structure of this invention is a semi-enclosed space formed by the grooved scale covering layer of the base arranged in a diamond array. This structure forms a stable, continuous liquid film, transforming the solid-liquid contact between turbulent flow and the covering layer into liquid-liquid contact between the turbulent flow and the liquid film. This acts as a fluid lubricant, reducing noise generated by friction and achieving a sound-absorbing function. Furthermore, the acoustic properties of the material used in this invention effectively suppress the transmission of internal and external noise from underwater vehicles, thereby achieving acoustic stealth. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0023] Figure 3 yes Figure 2 Schematic diagram of the relative positions of the spring, local resonant 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 part A of the groove scale covering layer unit with the micro-spring tensioning structure as the base of the present invention

[0026] Figure 6 This is an enlarged view of the groove scales of the present invention

[0027] Figure 7 It 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] Figure 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 streamlines; 12. Low-speed vortex; 13. Hydrodynamic noise; 14. External noise; 15. Cabin internal noise; 16. Grooved scale drag reduction, noise suppression and sound absorption covering layer. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings.

[0033] To mimic the vibration-absorbing and cushioning properties of fish skin, the present invention designs a grooved scale drag-reducing, noise-suppressing, and sound-absorbing covering layer based on a microspring tensioning structure. The microspring tensioning mechanism is a novel noise-suppressing mechanism. The upper platform, connected by microsprings and local resonance rods, can mimic the multi-dimensional motion of fish skin and strongly attenuate vibrating elastic waves, effectively weakening the excitation of turbulent flow on its surface and shell vibration, thereby achieving fluid noise reduction. Furthermore, the local oscillators of the local resonance rods that comprise the tensioning structure effectively absorb vibration energy, generating vibration wave band gaps, thereby further weakening and suppressing vibration transmission and achieving vibration reduction and sound absorption.

[0034] like Figure 1 As shown, the present invention discloses a grooved scale drag reduction, noise suppression, and sound absorbing covering layer based on a microspring tensioned structure, comprising a plurality of microspring tensioned structure grooved scale units 1. The plurality of microspring tensioned structure grooved scale units 1 are arranged in a diamond array and fixed to an underwater vehicle hull 2 ​​to form a covering layer with drag reduction, noise suppression, and sound absorbing functions.

[0035] Combine Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , the micro-spring tensioning structure groove scale unit 1 is described in detail: the micro-spring tensioning structure groove scale unit 1 includes a groove scale 3, an upper platform 4, three upper connecting hinges 5, 18 springs 6, six local resonance rods 7, 18 local oscillators 8, three lower connecting hinges 9 and a lower platform 10; the groove scale 3 is made of polyurethane material and is fixed to the upper end face of the upper platform 4 by strong glue. The edges of the groove scales are arcs of equal radius, ensuring that the groove scales 3 can maximize the reconstruction of the groove scale diamond array structure after being arranged in a diamond array. Three upper connecting hinges 5 are fixed to the concentric circles 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 concentrically to the upper end surface of the lower platform 10 using strong glue. 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 ends of the longitudinally arranged local resonant rod 7 are respectively fixed to the adjacent upper connecting hinges 5 and short connecting hinges 9b. The transversely arranged local resonant rod 7 has one end fixed to the long connecting hinge 9a, while the other end is suspended in the air. The suspended end is connected to the long connecting hinge 9a and short connecting hinge 9b below the suspended end and the upper connecting hinge 5 at the lower end of the upper platform 4 via three microsprings 6. The springs 6 are connected to the local resonant rod 7 by welding. Three nodes in the middle of the local resonant rod 7 are used to fix the rubber vibration damping ring 8a of the local oscillator. The steel shell 8b of the local oscillator is fixed to the outside of the rubber vibration damping ring 8a of the local oscillator with glue. The two ends of the local resonance rod 7 are fixedly connected to the adjacent upper connecting hinge 5 and lower connecting hinge 9 by strong glue, forming Figure 2 The micro-spring tension structure groove scale unit 1 is shown.

[0036] Combine Figure 7 and Figure 8The drag-reducing and noise-reducing properties of the present invention are described below: A drag-reducing, noise-reducing, and noise-reducing covering layer 16, constructed from a microspring-tensioned, diamond-shaped array of grooved scales, is affixed to the surface of the underwater vehicle's hull 2. During flow, clockwise, low-speed vortices 12 appear behind the grooved scales 3. These vortices prevent external fluid from entering the grooves, directing high-speed flow away from the near-wall region, effectively reducing near-wall velocity and significantly attenuating turbulence. Due to the presence of these low-speed vortices 12, fluid passing through the scale units is gradually lifted, reaching its highest point at the outer edges of the scales. Periodic wall oscillations reduce longitudinal vorticity, and the fluctuating streamlines 11 control the generation and development of turbulence, thereby reducing the fluid drag experienced by the underwater vehicle during navigation. Furthermore, the semi-enclosed space formed by the grooved scale covering layer, formed in a diamond-shaped array and based on the microspring-tensioned structure, forms a stable, continuous liquid film. This transforms the solid-liquid contact between the turbulent flow and the covering layer into liquid-liquid contact between the turbulent flow and the liquid film, acting as a fluid lubricant, reducing frictional noise and achieving noise reduction.

[0037] Combine Figure 9 The noise suppression characteristics of the present invention are described below: The grooved scale covering layer 16, based on a microspring tensioning structure, is a regular tetrahedron tensioning structure with microsprings. When the local vibrator 8 in the structure moves, the rubber vibration damping ring drives the metal shell to form an additional mass block, which absorbs energy from the grooved scales. This effectively attenuates the vibration elastic waves generated by external noise 14, thereby effectively weakening the vibration and achieving noise suppression. The grooved scale rhombus array covering layer 16, based on the microspring tensioning structure, is fixed to the surface of the underwater vehicle hull 2. The unique periodic structure formed by the covering layer and the acoustic properties of its material composition can suppress the reflection and transmission of external noise 14 and internal cabin noise 15, thereby achieving a noise suppression effect.

[0038] Among them, the relevant structural parameters of the groove scale unit 1 of the microspring tensioning structure of the present invention (microspring stiffness, damping and local oscillator mass, etc.) 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 motion 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 foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A grooved scale unit based on a micro-spring tensioning 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) includes 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. The groove scale unit based on the micro-spring tensioning structure according to claim 1, characterized in that: The grooved scales (3) are modeled after the surface morphology of the scales of cyprinid 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 tensioning 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 a micro-spring tensioning structure according to claim 1, characterized in that: The distance between each upper connecting hinge (5) and the central axis of the upper platform (4) is equal.

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

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

7. The groove scale unit based on a micro-spring tensioning structure according to claim 1, characterized in that: The middle part of the local resonance rod (7) has several nodes 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 absorption covering layer based on a micro-spring tensioning structure, characterized by: The invention comprises a plurality of grooved flaked units (1) based on a micro-spring tensioning structure according to any one of claims 1 to 7, wherein the plurality of grooved flaked units (1) based on the micro-spring tensioning structure are arranged end to end in a diamond array and fixed on an underwater vehicle shell (2).

9. The grooved scale drag reduction, noise suppression and sound absorption 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 working, a low-speed vortex (12) in a clockwise direction appears at the rear of the grooved scale (3). 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 grooved scale (3). The periodic wall oscillation will lead to a decrease 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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