Double-Walled Fuel Line Coupling for Crash and Lightning Displacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fuel line coupling components for auxiliary fuel tanks in aircraft do not meet requirements for large relative displacements during crashes, lightning protection, and quick disconnect features, often using simple metal piping and standard flexible couplings which fail to ensure leakage prevention and compliance with certification standards.
Innovation Solution
A fuel line coupling component with coaxially displaceable tubular members, ball and socket connections, and electrical bonding features, allowing axial, rotational, and radial displacements, along with quick disconnect capabilities using terminal end connectors and band clamps with turnbuckle adjustments for secure and reliable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If simple metal piping and standard flexible couplings are used, then device complexity is reduced, but the ability to handle large relative displacements during crashes and provide lightning protection is insufficient
Solution Approach 1:
The coupling device is divided into multiple functional segments: an outer coupling body with lightning protection features, an inner coupling member with displacement accommodation mechanisms, sealing elements, and electrical bonding components. This segmentation allows each part to specialize in specific functions (lightning protection, displacement handling, sealing) while maintaining overall system reliability without excessive complexity.
Solution Approach 2:
The inner coupling member is nested within the outer coupling body, creating a compact multi-functional assembly. The inner member handles axial and radial displacements while the outer member provides lightning protection and structural support. This nesting arrangement maximizes functional density while controlling overall device complexity.
2Reliability
If double wall construction with quick disconnect feature is implemented, then leakage prevention and certification compliance are improved, but device complexity increases
Solution Approach 1:
The coupling device incorporates pre-configured sealing elements (O-rings, gaskets) and electrical bonding straps that are already in place before connection. The quick disconnect mechanism includes pre-positioned lugs and receptacles that enable rapid attachment and detachment without requiring complex alignment procedures or additional sealing steps, thus maintaining reliability while enabling quick operation.
Solution Approach 2:
The coupling device integrates multiple functions into a single assembly: mechanical connection, sealing (leakage prevention), lightning protection, electrical bonding, and quick disconnect capability. The outer and inner coupling members work together to provide dual-wall construction for enhanced reliability while maintaining a unified structure that doesn't excessively increase 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
The solution enables aircraft fuel systems to meet survivable crash and lightning strike certification requirements while ensuring secure and leak-proof connections, allowing for flexible and reliable fuel line management during aircraft operations.
Implementation Method 1
The journalled connection assembly associated with the terminal end connectors may be a ball and socket connection assembly. More specifically, ball segments may be positioned at respective distal terminal ends of the outer and inner tubular members while socket segments may be defined by the terminal end connectors so as to journally receive a respective one of the ball segments.
Implementation Method 2
The terminal end connectors of certain embodiments may include respective electrical bonding straps to electrically bond the terminal end connectors to the outer tubular sections of the outer tubular member. Similarly, the inner tubular member may include pairs of static brushes to electrically bond the inner tubular sections to the terminal end connectors.
Data Source
AI summary
A fuel line coupling component (e.g., for aircraft fuel lines) allow for axial, rotational and radial displacements. The fuel line coupling component includes outer and inner tubular members with each having coaxially aligned pairs of coaxially sleeved tubular sections that are coaxially displaceable relative to one another. A pair of terminal end connectors includes a journalled connection assembly with the respective opposed distal ends of the outer and inner tubular members to thereby allow simultaneous rotational movements of the outer and inner tubular members about a longitudinal axis thereof and simultaneous radial displacements of outer an inner tubular members relative to a reference plane. C-clamps associated with fuel tank fittings and band clamps allow coupling of the fuel line coupling component to the fuel tank fittings and thereby fluid-connect aircraft fuel tanks (e.g., the aircraft main and auxiliary fuel tanks).