Low-flow-resistance underwater sound insulation device

Abstract

The invention provides a low-flow-resistance underwater sound insulation device which is characterized by comprising a plurality of air bags with the longitudinal sections in the shape capable of being densely laid. A set gap is kept between every two air bags, and the air bags are perpendicular to the water surface The device has the advantages that the broadband sound insulation performance is excellent, the main frequency band of underwater noise measurement is covered, and the influence of various noise sources on the test environment can be effectively inhibited; the hydrodynamic compatibility is good, the through-flow design of air bag array arrangement can maintain low flow resistance while realizing sound isolation, and significant disturbance to a test environment is avoided; and the modular design of the air bag is convenient to install, maintain and expand, and large-scale deployment in various water area environments is facilitated.

Description

Technical Field

[0001] This application belongs to the field of underwater acoustic measurement and marine engineering technology, specifically relating to a low-flow-resistance underwater sound insulation device. Background Technology

[0002] With the rapid development of underwater exploration, marine engineering, and military equipment technologies, the demand for accurate assessment of the acoustic performance of underwater equipment is becoming increasingly urgent. In complex aquatic environments such as rivers, lakes, and harbors, underwater noise measurement has long faced the challenge of strong environmental noise interference. Broadband background noise generated by water turbulence, ship navigation, and aquatic biological activities easily superimposes with the target equipment's own radiated noise, leading to measurement signal distortion and severely restricting the reliability of equipment acoustic characteristic analysis and performance optimization.

[0003] Currently, the design of underwater sound insulation structures must simultaneously address both acoustic and hydrodynamic constraints. Traditional sound insulation solutions often focus on sound wave isolation but struggle to meet low flow resistance requirements, easily leading to increased water flow resistance and decreased structural stability. Furthermore, most existing structures have limited sound insulation efficiency over a wide frequency range, particularly in the mid-to-low frequency bands, failing to meet the demands of complex underwater acoustic measurement scenarios for wide-bandwidth, high-precision noise control. Therefore, achieving a synergistic optimization of wide-bandwidth, high-efficiency sound insulation and good hydrodynamic performance under limited space and load conditions has become a critical technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of existing technologies, such as difficulty in meeting the requirements of low flow resistance, which can easily lead to increased water flow resistance and decreased structural stability.

[0005] To achieve the above objectives, this application proposes a low-flow-resistance underwater sound insulation device, comprising: Multiple airbags with a longitudinal cross-section that can be closely laid out; each airbag is spaced at a set interval and is deployed vertically to the water surface.

[0006] As an improvement to the above device, the set gap is less than half the wavelength corresponding to the set frequency; the set frequency is the maximum frequency for which sound insulation is required.

[0007] As an improvement to the above-mentioned device, the side length of the airbag is 5-40 times the airbag spacing, and the thickness is 5cm-30cm; the wall thickness of the airbag is 1mm-5mm.

[0008] As an improvement to the above-mentioned device, the airbag is made of rubber, PVC or polyurethane.

[0009] As an improvement to the above-mentioned device, adjacent airbags are connected by a shackle method.

[0010] As an improvement to the above-mentioned device, the longitudinal section of the airbag is a square, rectangle, rhombus, regular hexagon, or other polygonal shape that can be tessellated.

[0011] Compared with existing technologies, the advantages of this application are: 1. Excellent wideband sound insulation performance, covering the main frequency bands of underwater noise measurement, and can effectively suppress the influence of various noise sources on the test environment; 2. It has good hydrodynamic compatibility. The flow design of the airbag array arrangement achieves acoustic isolation while maintaining low flow resistance, avoiding significant disturbance to the test environment. 3. It has good engineering applicability and economy. The modular design of the airbag facilitates installation, maintenance and expansion, and is conducive to large-scale deployment in various aquatic environments. Attached Figure Description

[0012] Figure 1 The diagram shows a low flow resistance underwater sound insulation structure with an airbag array arrangement. Figure 2 The image shows the sound pressure levels at test points from 50Hz to 400Hz before and after the installation of the low-flow-resistance underwater sound insulation structure. Figure 3 The image shows the sound pressure levels at test points from 400Hz to 4000Hz before and after the installation of the low-flow-resistance underwater sound insulation structure. Detailed Implementation

[0013] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0014] This application provides a low-flow-resistance underwater sound insulation device. Based on an array of airbags, the device utilizes the extremely high acoustic impedance difference between air and water, combined with the free-boundary waveguide's blocking mechanism for planar sound waves, to achieve efficient sound wave isolation over a wide frequency range. Simultaneously, reasonable gaps are maintained between the airbag units to ensure smooth water flow and prevent excessive water resistance from affecting the system's stability and safety. This design is modular, lightweight, and cost-controllable. The materials and processes are easy to engineer and maintain, providing reliable technical support for high-precision measurement of equipment noise in complex aquatic environments.

[0015] This application provides a low-flow-resistance underwater sound insulation device, which consists of an array of airbags with a longitudinal cross-section that can be closely spaced (such as squares, rectangles, rhombuses, regular hexagons, or other combinations of polygons). A certain gap is maintained between the airbags to reduce flow resistance and allow water to flow smoothly. When it is necessary to ensure frequency... f 0 When good sound insulation is achieved, the airbag gap d should be less than the frequency. f 0 Corresponding wavelength λ 0Half of, i.e., d < λ 0 / 2. For most underwater applications requiring broadband sound insulation and low flow resistance, the airbag spacing can be designed between 5cm and 30cm. While ensuring the designed airbag spacing, the side length of a single airbag should be set to 5-40 times the airbag spacing, the thickness should be set within the range of 5cm-30cm, and the airbag wall thickness should be set within the range of 1mm-5mm. Airbags can be made of materials such as rubber, PVC, and polyurethane; ensuring the required shape and spacing after inflation will achieve the desired sound insulation effect. Based on the above technical solution, Figure 1 The paper introduces a highly practical underwater sound insulation structure, which consists of a rectangular airbag array. In the schematic diagram, the gray part is a single airbag. The airbags can be connected by shackles to form a modular underwater sound insulation structure. The blue part is the gap between the airbag units. By adjusting the gap between the airbags, the dual requirements of low flow resistance and sound insulation can be achieved.

[0016] For underwater equipment in complex waterways such as rivers, lakes, or harbors, this method involves enclosing or isolating the equipment under test to effectively attenuate external environmental noise and provide an "acoustic quiet zone" for high-precision measurement of the equipment's own noise. A modular airbag array can be vertically deployed and suspended underwater using counterweights and supports. After the sound insulation structure is inflated and spatially locked, the acoustic characteristic testing and analysis process is initiated to quantitatively verify its sound insulation performance. Once the acoustic environment requirements for high-precision measurement are met, the equipment's acoustic characteristics are tested, analyzed, and its performance optimized.

[0017] To verify the feasibility and sound insulation effect of the low-flow-resistance underwater sound insulation technology proposed in this application, a sound insulation performance test was conducted on an underwater sound insulation structure with a cuboid airbag array arrangement. For example... Figure 1 As shown, each airbag is 1900mm long (Y direction), 750mm wide (X direction), and 200mm thick (Z direction). The airbag wall thickness is 2mm, and the airbag spacing is 100mm. Figure 2 and Figure 3 The test points for the sound pressure level of the low flow resistance underwater sound insulation structure before and after installation are given under two methods: low-frequency excitation of 50Hz-400Hz and wide-frequency excitation of 400Hz-4000Hz. The proposed underwater sound insulation device can achieve an average sound insulation of 33.7dB in the 50Hz-4000Hz range, which has good sound insulation performance.

[0018] This application utilizes the huge impedance difference between air and water inside the airbag, as well as the ability of the free boundary waveguide formed between the airbags to isolate planar sound waves, to achieve broadband and efficient underwater sound insulation at low cost while taking into account hydrodynamic performance, thereby providing a guarantee for the measurement of noise performance of underwater equipment.

[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. A low-flow-resistance underwater sound insulation device, characterized in that, include: Multiple airbags with longitudinal sections that can be closely spaced; Each airbag is positioned with a set gap between it and is deployed vertically to the water surface.

2. The low flow resistance underwater sound insulation device according to claim 1, characterized in that, The set gap is less than half the wavelength corresponding to the set frequency; the set frequency is the maximum frequency at which sound insulation is required.

3. The low flow resistance underwater sound insulation device according to claim 1, characterized in that, The side length of the airbag is 5-40 times the airbag spacing, and the thickness is 5cm-30cm; the wall thickness of the airbag is 1mm-5mm.

4. The low flow resistance underwater sound insulation device according to claim 1, characterized in that, The airbag is made of rubber, PVC, or polyurethane.

5. The low flow resistance underwater sound insulation device according to claim 1, characterized in that, The adjacent airbags are connected by a shackle.

6. The low flow resistance underwater sound insulation device according to claim 1, characterized in that, The longitudinal section of the airbag is a square, rectangle, rhombus, regular hexagon, or other polygonal shape that can be tessellated.

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