Inverted Track Beam Flange for Nacelle Noise Attenuation
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Solution Overview
Problem
Aircraft nacelles generate high levels of audible noise during normal operation, particularly due to the interaction of bypass flow and turbine engine core exhaust, which is not effectively mitigated by existing noise suppression methods.
Innovation Solution
Incorporating a noise suppressing structure with a latticework of hexagonal cells made of composite material within the nacelle, where the cell dimensions are tailored to specific sound wave frequencies, and relocating the track beam attachment flange to an inverted position to increase noise cancellation surface area and aerodynamic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a noise suppressing structure with latticework of hexagonal cells is incorporated in the nacelle, then noise attenuation across various frequencies is improved, but device complexity increases
Solution Approach 1:
The noise suppressing structure is divided into a latticework of hexagonal cells, where each cell acts as an independent noise cancellation unit. This segmentation allows the structure to attenuate noise across multiple frequencies simultaneously while maintaining a modular design that manages complexity through repetition of standardized cell units.
Solution Approach 2:
The hexagonal cells are constructed using composite materials that provide both structural integrity and acoustic absorption properties. The composite material construction allows the noise suppressing structure to achieve effective noise attenuation without excessive weight or complexity, as the materials inherently combine multiple functional properties.
2Productivity
If the track beam attachment flange is relocated to an inverted position, then aerodynamic performance and noise cancellation surface area are improved, but manufacturing complexity increases
Solution Approach 1:
The attachment flange is inverted relative to conventional configurations, with the flange extending in the opposite direction from the track beam. This inversion repositions the attachment interface to increase the effective noise cancellation surface area and optimize airflow patterns, while the fundamental attachment mechanism remains consistent with existing manufacturing capabilities.
Solution Approach 2:
The inverted flange configuration extends the attachment structure into a different spatial orientation, effectively increasing the surface area available for noise cancellation without adding significant manufacturing complexity. This dimensional repositioning allows the same attachment components to serve dual purposes: structural attachment and acoustic treatment.
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 noise suppressing structure effectively attenuates noise across various frequencies, reducing neighborhood noise and improving aerodynamic performance by optimizing airflow and noise cancellation capabilities.
Implementation Method 1
the noise suppressing structure effectively attenuates noise across various frequencies
Implementation Method 2
cell dimensions are tailored to specific sound wave frequencies
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A "U" shaped inverted track beam flange (320) for a thrust reverser (60) is described. The geometry of the inverted track beam flange (320) increases the total noise cancellation capabilities of a nacelle structure comprising the inverted track beam flange (320). An inner fixed structure (105) is coupled to an inverted track beam flange (320). The inner fixed structure (105) is coupled to the inverted track beam flange (320) along an attachment flange (315). The coupling is along a commercial jet aircraft engine fan duct airflow surface.