Acoustic Core Protuberance Structure for Broad-Frequency Noise Damping
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Solution Overview
Problem
Existing acoustic cores used in turbomachines have varying degrees of acoustic absorption across different frequencies, leading to unsatisfactory performance in attenuating sound waves, particularly at specific absorption frequencies.
Innovation Solution
The development of acoustic cores with resonant cells featuring sound-attenuating protuberances formed through additive manufacturing, where the protuberances have a random or semi-random orientation and size, integrated into the cell walls, enhancing acoustic absorption properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional acoustic cores with regular resonant cells are used, then the structure is simple to manufacture, but the acoustic absorption is insufficient at certain frequencies
Solution Approach 1:
The acoustic core incorporates a porous material with randomly distributed pores throughout its structure. This porous structure provides enhanced acoustic absorption across a broader frequency spectrum compared to traditional regular-cell structures, while the random pore distribution naturally complicates the manufacturing process
Solution Approach 2:
The acoustic core is constructed as a composite structure combining a rigid framework with a porous infill material. This composite approach allows the core to maintain structural integrity while achieving superior acoustic absorption properties through the porous material's ability to dissipate acoustic energy across multiple frequencies
2Reliability
If acoustic cores are designed for broad frequency absorption, then the acoustic performance improves, but the manufacturing complexity increases
Solution Approach 1:
The patent varies key parameters of the resonant cells including wall thickness, cell size, and material density to optimize acoustic absorption across different frequencies. By adjusting these parameters, the core achieves broad-spectrum absorption while maintaining compatibility with existing manufacturing processes
Solution Approach 2:
The acoustic core is divided into multiple zones or layers, each with different cellular structures or material properties optimized for specific frequency ranges. This segmentation allows each zone to target particular frequencies, achieving overall broad absorption while using standardized manufacturing techniques for each segment
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 cores with sound-attenuating protuberances effectively dampen or attenuate sound waves across a range of frequencies, improving noise suppression in turbomachines by intentionally introducing additive-manufacturing material to form incidental protuberances during the manufacturing process, which would not typically be achievable by direct additive manufacturing.
Implementation Method 1
The acoustic core includes a plurality of resonant cells. At least some of the resonant cells have a multitude of sound-attenuating protuberances formed of the additive-manufacturing material of the cell walls integrally protruding into the resonant space
Implementation Method 2
The perforated face sheet allows sound waves to enter the acoustic core. The acoustic core includes a plurality of resonant cells intended to dampen or attenuate sound waves
Data Source
AI summary
An acoustic core has a plurality of cell walls formed of an additive-manufacturing material and a resonant space defined by the plurality of cell walls. At least some of the resonant cells have sound-attenuating protuberances formed of an excess amount of the additive-manufacturing material having been intentionally introduced to the cell walls and protruding into the resonant space with a semi-random orientation and/or size.