Chamfered Sound Inlet Recesses for Wideband Acoustic Absorption
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Solution Overview
Problem
Existing sound-absorbing building panels have limited sound absorption properties, particularly in wide frequency ranges, and are often costly and complex to manufacture.
Innovation Solution
The building board features sound entry recesses with a majority having a beveled mouth angle between 70° and 140°, specifically 75°-85° or 95°-120°, and a width of 0.1-2.5mm, with a depth of 0.3-6mm, arranged in rows or randomly, covering 2-10% of the surface area, made from materials like wood, light metals, or plastics, and optionally connected to a support with a cavity for enhanced sound absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vertical bores are provided in the panel surface, then sound absorption is achieved, but the quantitative sound absorption effect is not high
Solution Approach 1:
The invention changes the geometric parameters of the sound inlet recesses by introducing chamfers with specific angles (30°-60°) at the openings. This parameter modification transforms the acoustic impedance at the opening, enhancing the sound absorption coefficient across a broader frequency range and improving overall quantitative absorption performance compared to simple vertical bores.
Solution Approach 2:
The invention applies different geometric characteristics to different parts of the sound inlet recesses: the main body remains as simple vertical bores for ease of manufacture, while the openings are equipped with chamfers at specific angles to optimize acoustic performance. This local differentiation allows the system to achieve high sound absorption without complicating the entire structure.
2Reliability
If through-slots with non-perpendicular walls are used, then absorption performance shifts upward by one octave, but overall absorption performance is not improved
Solution Approach 1:
Instead of changing the wall angles of through-slots (which only shifts frequency response), the invention changes the opening geometry by adding chamfers at 30°-60° angles. This parameter change enhances the acoustic impedance matching at the opening, improving overall absorption performance across multiple octaves rather than just shifting the frequency response curve.
3Reliability
If micro-slots with steep funnel-shaped walls are provided, then sound absorption is enhanced, but complex manufacturing processes are required
Solution Approach 1:
The invention applies chamfers only at the openings of simple vertical bores rather than creating complex funnel-shaped walls throughout the entire slot structure. This local application of geometric modification achieves enhanced sound absorption while maintaining the simplicity of manufacturing, as chamfers can be easily added to drilled holes without requiring complex molding or machining processes.
4Reliability
If large circular sound inlet recesses are provided, then low-frequency absorption is increased, but wide frequency range absorption is limited
Solution Approach 1:
The invention segments the sound inlet structure into multiple small recesses with chamfers rather than using large circular openings. The chamfered geometry of each small recess contributes to broadband absorption, and the collective effect of multiple segmented openings achieves both low-frequency and wide frequency range absorption 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
This design achieves high sound absorption across a wide frequency range with simplified manufacturing, maintaining mechanical stability and aesthetic adaptability, while improving sound absorption performance compared to prior art.
Implementation Method 1
sound-absorbing panels for indoor or outdoor use are often provided with holes, indentations, wave patterns, or grooves to absorb or redirect sound waves
Implementation Method 2
allow at least some of the sound to dissipate within them or to superimpose reflected sound components onto incoming sound, thereby canceling them out
Data Source
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AI summary
Building panel (1), in particular wall or ceiling panel, with sound absorption properties, which has a top and a bottom, wherein a plurality of sound inlet recesses (2) are arranged on the sound-inserting or visible top side, and wherein each sound inlet recess has a width and a wall (5) that is substantially perpendicular to the top side and borders an edge surrounding the sound inlet recess, wherein the majority of at least 85% of the sound inlet recesses have a terminal chamfer (6) which is located in a predetermined angular range with one or more angles α at least in a partial section of the edge to the respective wall, wherein the angles α deviate from 90°.