Acoustic Multi-Element Panel for Broad-Frequency Noise Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic attenuation structures are limited to narrow frequency ranges and face issues with increased dimensions and poor sealing due to complex geometries and positioning challenges.
Innovation Solution
An acoustic attenuation structure with complex acoustic elements surrounded by partitions forming a continuous network, allowing for increased cell projection height and reduced overall dimensions, while ensuring precise positioning and sealing through a manufacturing method using injection of thermoplastic or thermosetting materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If simple cell shapes such as conventional NIDA structure are used, then the structure is easy to manufacture, but the acoustic performance is limited to absorption of a very narrow frequency range
Solution Approach 1:
The acoustic panel is segmented into multiple acoustic cells arranged in a grid pattern, with each cell containing a complex acoustic element (truncated cone or pyramid). This segmentation allows the panel to handle multiple frequency ranges simultaneously, overcoming the limitation of simple cell shapes while maintaining manufacturability through standardized cell configurations.
Solution Approach 2:
The patent introduces asymmetric complex acoustic elements (truncated cones and pyramids) within the acoustic cells, replacing symmetric simple cell shapes. These asymmetric geometries create varied acoustic paths and resonance characteristics, enabling broader frequency range absorption while the overall grid structure remains regular for ease of manufacture.
2Adaptability or versatility
If two cellular bodies having different shapes and dimensions are superimposed to increase frequency range, then the acoustic performance improves, but the overall dimensions of the acoustic attenuation structure are significantly increased
Solution Approach 1:
The patent embeds multiple types of complex acoustic elements (truncated cones and pyramids) within a single integrated cellular structure rather than superimposing separate cellular bodies. This nesting approach allows different acoustic elements to coexist in the same spatial envelope, achieving broad frequency range absorption without significantly increasing overall dimensions.
Solution Approach 2:
The patent utilizes the vertical dimension within each acoustic cell by creating complex 3D acoustic elements (truncated cones and pyramids) that extend from the front to the back of the panel. This dimensional utilization allows multiple acoustic functions to be packed into a compact thickness, avoiding the need to increase panel area.
3Adaptability or versatility
If open truncated cones are interconnected by strips positioned in notches to improve acoustic performance, then the frequency range increases, but the positioning control and sealing between elements become difficult to implement
Solution Approach 1:
The patent merges the acoustic elements (truncated cones and pyramids) with the partition walls forming the acoustic cells into a single integrated structure. This combining eliminates the need for separate strips and notches, ensuring precise positioning and perfect sealing through monolithic construction, while maintaining the complex geometries needed for broad frequency range absorption.
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 structure effectively attenuates sound waves at lower frequencies over extended frequency ranges with reduced dimensions and ensures perfect sealing, simplifying manufacturing by ensuring accurate positioning and assembly.
Implementation Method 1
such panels form Helmholtz-type resonators that make it possible to attenuate acoustic waves within a certain frequency range
Implementation Method 2
acoustic attenuation structures used to reduce the noise produced in airplane engines such as in gas turbines or the exhaust thereof
Data Source
AI summary
A method for manufacturing an acoustic attenuation structure including a complex acoustic multi-element panel extending along a horizontal and a vertical direction and an acoustic skin covering one of horizontal faces of the complex acoustic multi-element panel, the complex acoustic multi-element panel including complex acoustic elements each having a shape gradually narrowing between a base and a tip and partitions surrounding each complex acoustic element to form a plurality of acoustic cells, the partitions extending along the vertical direction from the base of the complex acoustic elements, the complex acoustic multi-element panel being produced by injection of a filled or unfilled thermoplastic or thermosetting material. The complex acoustic multi-element panel and the plurality of partitions are produced as a single part by injection of a filled or unfilled thermoplastic or thermosetting material.