Acoustic Panel with Cellular Core and Structural Reinforcements
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Solution Overview
Problem
Aircraft gas turbine engines generating low-frequency noise pose a challenge for acoustic panels due to space constraints, which limit the thickness of the panels needed to tune resonating chambers for noise attenuation, while reducing thickness compromises structural integrity.
Innovation Solution
The acoustic panel design incorporates a cellular core with corrugated support walls and structural reinforcements, including ribs and septums, to increase rigidity and strength, allowing for effective noise attenuation without increasing panel thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the core thickness is increased to tune resonating chambers for low-frequency noise attenuation, then noise attenuation performance is improved, but panel thickness increases which is prohibited by space constraints
Solution Approach 1:
The patent introduces corrugated support walls with alternating peaks and valleys that create an extended acoustic path length within a compressed thickness dimension. The corrugations fold the acoustic path into the thickness dimension, allowing sound waves to travel a longer effective path through the resonating chambers without increasing the overall panel thickness, thereby enabling low-frequency noise attenuation while maintaining space constraints.
Solution Approach 2:
The corrugated support walls feature curved profiles with alternating peaks and valleys rather than straight lines. This curvature creates a folded acoustic path that increases the effective length of resonating chambers within the available thickness, allowing the panel to attenuate low-frequency noise without requiring increased thickness that would violate space constraints.
2Length of stationary object
If the panel thickness is reduced to meet space constraints, then space utilization is improved, but structural integrity is compromised
Solution Approach 1:
The panel is segmented into multiple functional layers: perforated face skin, cellular core with corrugated support walls, and solid back skin. The cellular core is further segmented into multiple cells by partition walls. This segmentation distributes structural loads across multiple elements, maintaining structural integrity even when the overall panel thickness is reduced to meet space constraints.
Solution Approach 2:
The panel employs a composite structure combining perforated face skin, cellular core material with corrugated support walls, and solid back skin. This composite construction provides enhanced structural integrity and rigidity while maintaining a reduced overall thickness, resolving the contradiction between meeting space constraints and preserving structural strength.
3Strength
If corrugated support walls are added to increase rigidity, then structural integrity is improved, but device complexity increases
Solution Approach 1:
The corrugated support walls serve multiple functions simultaneously: they provide structural rigidity and strength to the panel, define the resonating chamber geometry for noise attenuation, and create the folded acoustic path within limited thickness. This multi-functionality increases rigidity without proportionally increasing complexity, as a single structural feature accomplishes multiple objectives.
Solution Approach 2:
The patent merges the structural support function with the acoustic resonance function by making the support walls themselves form the boundaries of the resonating chambers. The corrugated support walls are not separate reinforcement elements but are integrated into the acoustic cell structure, combining structural integrity enhancement with noise attenuation functionality while minimizing additional complexity.
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 effectively attenuates low-frequency noise without compromising structural integrity by utilizing a cellular core with corrugated structures and structural reinforcements, enhancing the panel's ability to manage noise while maintaining structural stability.
Implementation Method 1
The honeycomb core includes a plurality of resonating chambers. These resonating chambers are tuned by selecting a desired chamber length and, thus, core thickness that corresponds to a specific target frequency of noise to be attenuated.
Data Source
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AI summary
A panel is provided for attenuating sound. This panel includes a perforated first skin (102), a second skin (104) and a core (106). The core (106) forms a plurality of cavities (128) vertically between the perforated first skin (102) and the second skin (104). The core (106) includes an array of corrugations (126) that include a first baffle (130), a second baffle (130) and a first septum (132). The cavities (128) include a first cavity (128)formed longitudinally between the first baffle (130) and the second baffle (130). The first cavity (128) is fluidly coupled with perforations (114) in the first skin (102). The first septum (132) extends from the first skin (102) and the first baffle (130) to the second skin (104) and the second baffle (130). The first septum (132) divides the first cavity (128) into fluidly coupled sub-cavities (128A, 128B). At least one element of the panel includes at least one first rib (160) and at least one second rib (162), the first rib (160) extends along a first trajectory and the second rib (162) extends along a second trajectory that is non-parallel with the first trajectory.