Aircraft Duct Stringer Bayonet Fitting for Secure Fluid Conduit Joining
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Solution Overview
Problem
Existing duct stringer systems for aircraft lack a secure and straightforward method to connect fluid transporting conduits, often requiring complex components that protrude into the duct, which can interfere with fluid flow and increase the risk of electrostatic build-up or flow interruption.
Innovation Solution
A duct stringer with a female bayonet fitting integrated into the duct wall, featuring slots and retaining recesses that engage with a male bayonet fitting on the conduit, allowing for secure connection without protruding members, using a locking mechanism with a threaded pin for additional security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex connection components are used to securely connect conduits to ducts, then connection reliability is improved, but device complexity increases and protruding members interfere with fluid flow
Solution Approach 1:
The female bayonet fitting integrates multiple connection functions (engagement, retention, alignment) into a single integrated component formed directly in the duct wall aperture, eliminating the need for separate protruding connection members and reducing overall device complexity while maintaining secure connection reliability
Solution Approach 2:
The duct wall aperture serves multiple functions: it provides fluid passage, houses the female bayonet fitting for mechanical connection, and integrates retention features, thereby eliminating the need for separate dedicated connection components and reducing device complexity
2Strength
If protruding connection members are used to secure conduits, then connection strength is improved, but fluid flow is interrupted and electrostatic build-up increases
Solution Approach 1:
The female bayonet fitting is nested within the duct wall aperture, with the male bayonet fitting on the conduit inserting into this recessed female fitting, allowing secure mechanical engagement without any connection members protruding into the fluid flow path, thereby maintaining smooth fluid flow and preventing electrostatic accumulation
Solution Approach 2:
The connection function is extracted from the fluid flow path and relocated to the duct wall aperture, where the bayonet fitting engages the conduit externally or at the wall surface, separating the mechanical connection function from the fluid transport function to eliminate flow interruption and electrostatic issues
Data Source
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AI summary
The present application relates to duct stringer. The duct stringer forms at least part of a duct with a closed cross-section which is adapted to transport fluid. The duct stringer has a duct wall and a female bayonet fitting in the duct wall. The female bayonet fitting is configured to engage with a male bayonet fitting on a fluid transporting conduit to connect the fluid transporting conduit with the duct. The present application also relates to an aircraft assembly comprising the duct stringer and the fluid transporting conduit.