Microcellular Rubber Acoustic Reflector for Deep-Sea Sonar
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing underwater acoustic reflectors face challenges in maintaining directionality and acoustic properties at elevated hydrostatic pressures and deep water depths, often suffering from water absorption and complex fabrication processes, which impairs their performance.
Innovation Solution
A composite acoustic energy reflector comprising a microcellular rubber core and a fiber-reinforced composite shell, utilizing an acoustic impedance mismatch between air cavities and water to achieve directional radiation and reception of acoustic energy, capable of withstanding high hydrostatic pressures and fabricated in various geometric shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional acoustic reflectors (cork, cellular material, balsa wood) are used, then acoustic reflection is achieved, but water absorption and performance degradation occur at elevated hydrostatic pressures
Solution Approach 1:
The patent employs a composite structure consisting of a flexible membrane enclosing a gas-filled cavity, backed by a rigid plate. This composite design combines the acoustic impedance mismatch benefits of gas-filled materials with the pressure resistance of rigid structures, eliminating water absorption while maintaining acoustic reflection performance at depth.
Solution Approach 2:
The patent uses a flexible membrane as the acoustic reflector surface, which encloses a gas-filled cavity. The flexible nature of the membrane allows it to withstand hydrostatic pressure without rigid structural support, preventing water absorption while maintaining acoustic properties. The membrane flexes under pressure rather than cracking or allowing water penetration.
2Ease of operation
If complex structures (corner reflectors with three perpendicular surfaces, stacked metallic mesh) are used, then directionality is improved, but device complexity and fabrication difficulty increase
Solution Approach 1:
The patent divides the acoustic reflector into two functional segments: a flexible membrane enclosing the gas-filled cavity for acoustic reflection, and a rigid plate for structural support and backing. This segmentation allows each component to be optimized independently and simplifies fabrication compared to monolithic complex structures.
Solution Approach 2:
The patent extracts the gas-filled cavity from within a rigid structure and encloses it with a flexible membrane instead. This extraction allows the acoustic reflector to achieve directionality through the membrane-cavity configuration without requiring complex rigid frameworks or multiple perpendicular surfaces.
3Strength
If rigid structures are used to withstand hydrostatic pressure, then pressure resistance is improved, but water absorption and acoustic property degradation occur
Solution Approach 1:
The patent uses a flexible membrane that can withstand hydrostatic pressure through elastic deformation rather than rigid structural support. The membrane's flexibility allows it to compress under pressure while maintaining its integrity and acoustic reflection properties, preventing the water absorption and performance degradation associated with rigid structures.
Solution Approach 2:
The patent changes the physical state of the filling material from solid (cork, balsa wood) to gas (air or other gas). This parameter change allows the reflector to withstand pressure without water absorption, as the gas-filled cavity compresses elastically under hydrostatic pressure while maintaining acoustic impedance mismatch for effective reflection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composite reflector maintains high efficiency and directionality across a wide range of hydrostatic pressures, prevents water absorption, and can be fabricated in any shape, enabling effective acoustic energy transmission and reception at various frequencies, suitable for both civil and military sonar applications.
Implementation Method 1
utilizing an acoustic impedance mismatch between air cavities and water to achieve directional radiation and reception of acoustic energy
Implementation Method 2
capable of withstanding high hydrostatic pressures
Data Source
Figure 1(a)~2
Figure 3(a)~3(b)
Figure 4A~4B
AI summary
The present invention relates to an acoustic energy reflector comprising a microcellular rubber as inner liner and a fiber reinforced composite as outer casing, in a core-shell assembly, wherein the said microcellular rubber is selected from the group of natural and synthetic rubbers having glass transition temperature below 0°C and the resin for the fiber reinforced composite is selected from a group having a glass transition temperature at least 50°C.