Multi-Core Acoustic Panel for Low-Frequency Sound Attenuation
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Solution Overview
Problem
Existing sound attenuation structures for aircraft propulsion systems struggle to effectively attenuate low-frequency sound waves while maintaining structural integrity.
Innovation Solution
A multi-degree of freedom acoustic panel with a cellular core configuration, comprising a honeycomb structure and corrugated ribbons, is integrated into the inner barrel of the propulsion system to attenuate sound waves by reversing their phase and promoting destructive interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional sound attenuation structures are used in the inner barrel, then structural integrity is maintained, but low-frequency sound wave attenuation is insufficient
Solution Approach 1:
The acoustic panel is segmented into a multi-core structure with multiple cellular cores (e.g., honeycomb cores) arranged in an array. Each core can be tuned to different frequencies, allowing the panel to attenuate a broader range of low-frequency sound waves while maintaining structural integrity through the distributed core architecture.
Solution Approach 2:
The acoustic panel employs composite construction by integrating multiple cellular cores with different materials and properties into a single panel structure. This composite approach enables the panel to achieve both the structural strength required for the inner barrel and the acoustic performance needed for low-frequency attenuation.
2Object-affected harmful factors
If a multi-core acoustic panel is integrated into the inner barrel, then low-frequency sound wave attenuation is improved, but device complexity increases
Solution Approach 1:
The multi-core acoustic panel serves multiple functions simultaneously: it provides structural support for the inner barrel, attenuates low-frequency sound waves, and can be designed to accommodate different frequency ranges through varying core configurations. This multi-functionality reduces the need for separate components, thereby managing complexity.
Solution Approach 2:
The acoustic panel integrates multiple cellular cores within a single panel structure, with each core nested within the overall panel assembly. This nesting approach allows the complex multi-core structure to be manufactured and installed as a single integrated component, reducing the practical complexity of integration into the inner barrel.
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 panel effectively attenuates low-frequency sound waves without compromising the structural integrity of the aircraft propulsion system, reducing noise disruption.
Implementation Method 1
attenuate sound waves by reversing their phase and promoting destructive interference
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
An apparatus is provided for an aircraft propulsion system (20). This apparatus includes an acoustic panel (72) and a mount (84). The acoustic panel (72) includes a perforated face skin (88), a back skin (89), a perforated intermediate layer (90), a first cellular core and a second cellular core. The first cellular core includes a first section (27A) and a second section (27A). The first section (27A) is between and is connected to the perforated face skin (88) and the perforated intermediate layer (90). The second section (27A) is between and is connected to the perforated face skin (88) and the back skin (89). The second cellular core is between and is connected to the perforated intermediate layer (90) and the back skin. The mount is attached to the back skin along the second section.