Nacelle Joint Fire Barrier Structure Without Expanding Mastic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for creating fire barriers at the joints of aircraft turbojet nacelles are either costly due to complex structures or ineffective in areas with no relative displacement, and current fire-resistant mastics expand and liquefy upon heat exposure, potentially igniting outside the fire zone.
Innovation Solution
A non-flammable, waterproof device with a predetermined shape is used to close spaces between nacelle elements, featuring a proximal end that matches complex shapes and a distal end for secure fixation, made from materials like metal, composite, or elastomer, which is designed to be inserted or cover spaces effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fire-resistant mastic is applied to seal joints between nacelle elements, then fire barrier protection is provided, but the mastic expands and liquefies when exposed to heat, potentially igniting outside the fire zone
Solution Approach 1:
The patent extracts the problematic mastic material from the joint sealing system and replaces it with a rigid fire-resistant barrier structure. The closing device comprises a fire-resistant structure that physically blocks the joint space without using organic sealants, thereby eliminating the source of harmful gas emissions while maintaining fire barrier protection.
Solution Approach 2:
The invention changes the physical state and material properties of the sealing solution from flexible organic mastic to rigid inorganic fire-resistant structure. This parameter change transforms the sealing mechanism from chemical bonding (mastic polymerization) to mechanical closure, preventing thermal degradation and ignitable gas release under fire conditions.
2Reliability
If complex sealing structures are used to ensure fire resistance, then fire barrier reliability is improved, but manufacturing costs increase
Solution Approach 1:
The closing device is segmented into modular components including a fire-resistant structure with multiple walls forming distinct chambers, and separate closing elements that can be independently manufactured and assembled. This segmentation allows for standardized production of individual modules while ensuring comprehensive fire barrier coverage at the joints.
Solution Approach 2:
The fire-resistant closing device serves multiple functions: it provides fire barrier protection, seals the joint space, structural reinforcement, and prevents gas migration. By integrating these functions into a single multi-functional component rather than using separate specialized elements, the design reduces overall system complexity and manufacturing cost while maintaining high reliability.
3Adaptability or versatility
If deformable sealing joints are used, then adaptability to relative displacements is improved, but device complexity and cost increase for joints without relative displacement
Solution Approach 1:
The patent applies local quality by providing fire-resistant closing devices at specific joint locations where fire barrier protection is required, rather than making the entire nacelle structure deformable. Each closing device is locally adapted to its specific joint geometry while maintaining a standardized design approach, ensuring fire protection without unnecessary complexity in joints without relative displacement.
4Ease of manufacture
If fire-resistant walls are made from multiple joined elements, then assembly flexibility is improved, but spaces at joints create fire barrier gaps
Solution Approach 1:
The closing device employs a nested structure where internal fire-resistant walls are positioned within external walls, creating multiple layers of fire barrier protection. The closing elements are inserted into and nested within the joint spaces between nacelle elements, ensuring that fire barrier continuity is maintained through the joint while allowing flexible assembly of the overall structure.
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 device provides an improved fire barrier that is resistant to heat and pressure, reducing manufacturing costs and preventing gas emissions that could ignite, while being adaptable to various space geometries and pressures.
Implementation Method 1
the device according to the invention is non-flammable to heat
Implementation Method 2
A non-flammable, waterproof device with a predetermined shape is used to close spaces between nacelle elements
Implementation Method 3
The sealant is suitable for filling spaces subject to any pressure value, and in particular spaces subject to pressures greater than 35 mbar
Data Source
Figure 1~2
Figure 3~4b
Figure 5~6
AI summary
Device (10, 20) for sealing a gap (100, 200) at a joint between elements (305, 306, 307, 308, 309) of a gondola, the device being non-flammable in heat, having a predetermined shape, and having a proximal end (11, 21) intended to be inserted into the gap (100, 200) to be sealed so as to seal it, and a distal end (12, 22) intended to be fixed to an element of the gondola (305, 306, 307, 308, 309) on the side where the fire is likely to start.