Aircraft Fuel Pressure Sensor Mounting Without Tank Intrusion
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Solution Overview
Problem
Existing fuel level sensors in aircraft fuel tanks are intrusive and require manual access for installation, replacement, and maintenance, posing challenges in efficiency and convenience.
Innovation Solution
A system utilizing a guide tube and optic fiber assembly, where the guide tube is sealed to the aircraft wing spar and an optical pressure sensor is coupled to the optic fiber, allowing for non-intrusive installation, removal, and maintenance of fuel level sensors without accessing the fuel tank interior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional fuel level probes are used, then fuel level measurement is achieved, but manual access to fuel tank interior is required for installation and maintenance
Solution Approach 1:
The system divides the sensor assembly into separate components: the optical pressure sensor is mounted externally on the fuel tank wall, while only the optical fiber tip extends into the fuel tank interior. This segmentation allows the majority of the sensor to be accessible for maintenance without entering the tank, resolving the contradiction between ease of operation and device complexity.
Solution Approach 2:
The optical fiber is extracted from the main sensor body and routed through a guide tube that passes through the fuel tank wall. This extraction allows the sensor housing to remain outside the fuel tank where it can be easily accessed for installation and maintenance, while only the essential sensing tip needs to be inside the tank to perform its function.
2Measurement precision
If intrusive probes are installed in fuel tanks, then pressure measurement capability is achieved, but access to tank interior is required for replacement and repair
Solution Approach 1:
A guide tube acts as an intermediary structure that passes through the fuel tank wall, allowing the optical fiber to extend into the tank interior for pressure measurement while keeping the main sensor assembly outside. This intermediary enables both precise measurement and easy repair without requiring access to the tank interior.
Solution Approach 2:
The system replaces traditional mechanical pressure sensors that require full insertion into the fuel tank with an optical sensing system. The optical fiber transmits light to sense pressure at the tip location while the sensor electronics remain outside, substituting mechanical intrusion with optical measurement to achieve both precision and ease of repair.
3Reliability
If sensors are mounted inside fuel tanks, then direct pressure measurement is achieved, but manual access is required for installation and maintenance
Solution Approach 1:
The system transitions from a three-dimensional insertion approach (mounting the entire sensor inside the tank) to a two-dimensional surface mounting approach (mounting the sensor on the external tank surface with fiber optic extension). This dimensional change allows reliable pressure measurement through the tank wall while minimizing installation and maintenance time by keeping the sensor accessible from the exterior.
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
Enables efficient and minimally invasive installation, replacement, and maintenance of fuel level sensors, eliminating the need for manual access to the fuel tank and reducing intrusion, while maintaining structural integrity and safety.
Implementation Method 1
An optical pressure sensor is optically coupled to the optic fiber proximate a second end of the guide tube
Implementation Method 2
A guide tube has a first end sealingly engaged in the opening of the vertical wing spar to prevent leakage between the guide tube and the opening. An optic fiber extends through the guide tube, sealingly engaged to the first end of the guide tube to prevent leakage between the optic fiber and the first end of the guide tube.
Data Source
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AI summary
A system includes an aircraft fuel tank defining an interior configured to store fuel for flight. The interior is defined by a plurality of tank walls including a vertical wing spar of a wing. An opening is defined through the vertical wing spar. A guide tube has a first end sealingly engaged in the opening of the vertical wing spar to prevent leakage between the guide tube and the opening. An optic fiber extends through the guide tube, sealingly engaged to the first end of the guide tube to prevent leakage between the optic fiber and the first end of the guide tube. An optical pressure sensor is optically coupled to the optic fiber proximate a second end of the guide tube opposite the first end.