Angle-Independent Acoustic Scatterers for Broadband Sound Absorption
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Solution Overview
Problem
Existing acoustic structures fail to effectively absorb sound across broad frequency ranges and maintain sound transmission loss independent of the angle of sound incidence.
Innovation Solution
The use of an acoustic scatterer with multiple repeating cells, each containing distinct resonant channels, and covered by two plates, which absorb soundwaves by constructive interference of monopole and dipole components, regardless of the angle of incidence, enhancing sound absorption and transmission loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional acoustic structures are used, then sound absorption is achieved at specific frequencies, but sound absorption across broad frequency ranges is not achieved
Solution Approach 1:
The acoustic structure is divided into multiple repeating cells, each containing distinct resonant channels with different resonant frequencies. This segmentation allows the structure to target multiple frequency bands simultaneously, achieving broadband sound absorption while maintaining effectiveness across the entire frequency range.
Solution Approach 2:
Different regions of the acoustic structure (different repeating cells) have locally optimized properties with distinct resonant frequencies. Each cell is designed with specific geometric parameters to resonate at targeted frequencies, collectively providing comprehensive broadband absorption coverage.
2Adaptability or versatility
If conventional acoustic structures are used, then sound transmission loss is achieved, but sound transmission loss independent of angle of incidence is not achieved
Solution Approach 1:
The resonant channels within each repeating cell feature asymmetric zigzag geometries with specific orientation angles. This asymmetric design creates angle-independent acoustic scattering properties, ensuring that sound transmission loss remains effective regardless of the incident angle of sound waves.
Solution Approach 2:
The acoustic structure incorporates three-dimensional zigzag resonant channels with orientation angles in multiple dimensions. This dimensional approach creates omnidirectional scattering effects that maintain sound transmission loss performance across all incident angles, achieving angle independence.
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 acoustic structure achieves broadband sound absorption of up to 75% and sound transmission loss of up to 19 dB across various frequencies, effectively reducing noise pollution in vehicles and other environments.
Implementation Method 1
each including a plurality of distinct resonant channels
Implementation Method 2
absorb soundwaves by constructive interference of monopole and dipole components
Implementation Method 3
constructive interference of monopole and dipole components
Implementation Method 4
acoustic scatterers are angle independent broadband acoustic absorbers
Data Source
AI summary
An acoustic structure includes at least one acoustic scatterer that is angle independent and has multiple resonant frequencies. Each acoustic scatterer contains at least one repeated cell. Each cell contains at least two distinct resonant channels capable of absorbing sound and improving sound transmission loss at distinct frequencies. Each resonant channel is identical to at least one other channel within the acoustic scatterer.