Acoustic Reflector Solid Core Spherical Shell
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing underwater acoustic reflectors face challenges such as toxicity from chlorofluorocarbon-filled shells, high manufacturing costs, and aspect-dependent reflectivity, making them unsuitable for marine applications and environmentally harmful.
Innovation Solution
A solid core acoustic reflector with a shell designed to focus and re-radiate acoustic waves, using materials like silicone for the core and glass-reinforced plastics or steel for the shell, ensuring a wave speed range of 840 to 1500 m/s and dimensioning the shell to enhance reflection, allowing for a durable, non-toxic, and cost-effective solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluid-filled spherical shell targets are used to achieve high target strength, then acoustic reflection is enhanced, but environmental harm and toxicity increase due to potential fluid leakage
Solution Approach 1:
The harmful fluid filling is extracted and replaced with air or gas filling, eliminating the environmental hazard while maintaining the spherical shell structure for acoustic reflection
Solution Approach 2:
The physical state of the filling is changed from liquid (toxic CFCs) to gas (air or inert gas), fundamentally altering the environmental compatibility while preserving acoustic reflector functionality
2Reliability
If triplane reflectors are used to achieve high target strength, then acoustic reflection is enhanced, but reflectivity becomes aspect-dependent with variations greater than 6 dB at different angles
Solution Approach 1:
The flat triangular planes are replaced with a spherical geometry, which naturally provides omnidirectional acoustic reflection characteristics, eliminating the aspect-dependency inherent in planar reflector designs
3Reliability
If coating materials are applied to triplane reflectors to enhance acoustic reflectivity, then target strength is improved, but reflectivity becomes prone to variation with pressure due to depth
Solution Approach 1:
The acoustic reflector functionality is extracted from the pressure-sensitive coating and transferred to the pressure-insensitive spherical shell structure itself, which maintains stable acoustic properties across varying depths
4Reliability
If liquid-filled sphere reflectors are used to achieve high target strength, then acoustic reflection is enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The complex liquid filling process and associated sealing requirements are extracted and replaced with simple air or gas filling, dramatically simplifying manufacturing while maintaining acoustic performance
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 solution provides a durable, non-toxic, and cost-effective acoustic reflector with enhanced target strength across various frequencies, improving distinguishability from background clutter and other targets, suitable for marine applications including marine mammal tracking.
Implementation Method 1
refracting input acoustic waves, incident on a side of a spherical shell such that they are focused along an input path onto an opposing side from which they are reflected and emitted as an output reflected response
Implementation Method 2
a portion of the acoustic waves incident on the shell are coupled into the shell wall and guided therein around the circumference of the shell and then re-radiated to combine constructively with the said reflected acoustic signal output
Data Source
AI summary
An acoustic reflector (10) suitable for use as a reflective target for navigational aids and for location and re-location applications. The acoustic reflector comprises a shell (12) arranged to surround a solid core (16). The shell is adapted to transmit acoustic waves (18) incident thereon into the core (16). Within the core the acoustic waves are focused before being reflected from an opposing side of the shell (20) to provide a reflected acoustic wave. A portion of the acoustic waves incident on the shell is coupled into the shell wall and guided within and around the circumference thereof (26) before being re-radiated and combining constructively with the reflected acoustic wave to provide an enhanced reflected acoustic wave.