Acoustic Liner Face Sheet With Streamlined Holes for Lower Turbulence
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Solution Overview
Problem
Existing acoustic liners in gas turbine engines experience flow disturbances due to turbulent airflow through perforated holes, leading to reduced engine performance and increased turbulence.
Innovation Solution
The face sheet of the acoustic liner features streamlined holes with elongated edges that align or offset from the flow direction, forming teardrop or slot shapes to minimize flow path disturbances, using additive manufacturing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If holes are made larger or wider slots are used, then acoustic treatment effectiveness is improved, but flow diffusion increases and turbulence is exacerbated
Solution Approach 1:
The patent applies curvature by forming streamlined holes with rounded edges instead of sharp corners. The elongated edges with rounded transitions create smoother flow paths that reduce turbulence and flow diffusion while maintaining adequate acoustic treatment effectiveness.
Solution Approach 2:
The patent employs asymmetry through non-circular hole shapes, specifically elongated shapes with different length and width dimensions. The elongated edges are positioned and dimensioned asymmetrically relative to the flow direction to optimize flow guidance and minimize disruptive turbulence while preserving acoustic performance.
2Ease of manufacture
If conventional round holes are used, then manufacturing is simple, but flow disturbance and drag are higher
Solution Approach 1:
The patent changes geometric parameters of the holes by transitioning from simple circular shapes to elongated shapes with specific length-to-width ratios. The elongated edges are designed with specific dimensional parameters to streamline flow while remaining compatible with conventional manufacturing processes like drilling or laser cutting.
3Object-generated harmful factors
If streamlined holes with elongated edges are used, then flow disturbance is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent segments the hole geometry into distinct features: an elongated base shape with specific length and width dimensions, rounded edges at the openings, and controlled edge lengths. This segmentation allows each feature to be optimized independently for flow management while maintaining manufacturability through standard fabrication techniques.
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 configuration reduces drag and performance loss, enabling higher engine efficiency and reduced noise and fuel consumption by guiding airflow smoothly over the holes.
Implementation Method 1
the face sheet having streamlined holes formed with elongated edges... the streamlining feature is aligned with a direction of flow over the face sheet... guiding airflow smoothly over the holes
Implementation Method 2
This configuration reduces drag and performance loss... the elongated edges... minimizing flow path disturbances
Data Source
Figure 1
Figure 2A
Figure 2B~3
AI summary
A face sheet (110A) of an acoustic liner (110) for a gas turbine engine (20), having: a first surface (120), a second surface (140), and a sheet body (130) extending from the first surface (120) to the second surface (140); a forward end (150), an aft end (160), and the sheet body (130) extending from the forward end (150) to the aft end (160); and a hole formed in the sheet body (130), extending from the first surface (120) to the second surface (140), the hole (170) defining a hole opening (220) at the first surface (120) of the face sheet (110A), and an elongated edge (250) that extends aft at the hole opening (220), wherein the elongated edge (250) defines a flow ramp surface (300) that tapers toward the first surface (120) and is configured to direct flow toward the first surface (120), wherein the flow ramp surface (300) is a streamlining feature.