Composite Aircraft Bleed Duct Weight Reduction
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Solution Overview
Problem
Current hot air bleed ducts in aircraft, made of titanium and steel, face challenges with high weight, susceptibility to deformation, and limitations in temperature and pressure resistance, while composite ducts lack suitable materials and designs for high-temperature, high-pressure applications with complex geometries.
Innovation Solution
Development of non-straight composite hot air bleed ducts using braided carbon fiber fabric and phenylethynyl-terminated imide resin, processed through Resin Transfer Molding (RTM) at high temperatures and pressures, achieving structural integrity and weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If titanium or steel materials are used for hot air bleed ducts, then temperature and pressure resistance are improved, but weight increases
Solution Approach 1:
The patent applies composite materials consisting of carbon fiber reinforcement and phenylethynyl-terminated imide resin to manufacture hot air bleed ducts that can withstand temperatures above 280°C and pressures above 4 bar. This composite material provides both the required thermal and pressure resistance while achieving 45% weight savings compared to traditional titanium ducts.
2Temperature
If titanium materials are used for hot air bleed ducts, then temperature resistance is improved, but deformation susceptibility increases
Solution Approach 1:
The carbon fiber reinforced phenylethynyl-terminated imide resin composite provides superior dimensional stability compared to thin titanium walls. The composite material structure with carbon fiber reinforcement maintains structural integrity and resists deformation under operating conditions and during assembly operations.
3Weight of moving object
If composite materials are used for ducts, then weight is reduced, but service temperature capability deteriorates
Solution Approach 1:
The patent changes the chemical and physical parameters of the resin material by selecting phenylethynyl-terminated imide resin with a glass transition temperature of 330°C, which enables the composite duct to operate at temperatures above 280°C. This parameter change in the resin's thermal properties allows composite materials to achieve previously unattainable high-temperature service capability.
4Adaptability or versatility
If complex geometries are required for bleed ducts, then functional performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent uses preliminary action by creating a mandrel with the desired complex geometry before manufacturing. The mandrel serves as a pre-formed template that guides the resin infusion process, allowing complex non-straight duct geometries to be manufactured through RTM without requiring complex tooling or assembly operations.
Solution Approach 2:
The patent replaces traditional mechanical forming methods with resin transfer molding (RTM). Instead of mechanically forming or assembling complex geometries from multiple parts, the liquid resin is infused into a mold containing the complex geometry, where it cures to form the final duct shape in a single integrated manufacturing step.
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 solution provides a lightweight, thermally stable, and pressure-resistant composite duct that exceeds the required temperature and pressure limits, with a 45% weight saving compared to titanium ducts and meeting all specified performance criteria, including FST behavior and resistance to deformation and leaks.
Implementation Method 1
the high temperature resin is configured to be injected or infused in a temperature range of 280-290°C and in a pressure range of 12-13 atm
Implementation Method 2
Thermal stability at Service work conditions. Thermal stability in case of thermal excursions of 30s-60s at 260°C or 5s at 290°C
Data Source
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AI summary
The invention provides non-straight ducts for conducting fluids at temperatures higher than 280ºC and pressures higher than 4 bar made of a composite material and, particularly, hot air bleed ducts of an aircraft made of a carbon-fiber reinforced polymer aimed to reduce weight of the bleeding system by replacing most of the metallic material from which the bleeding ducts are currently made.