Dual Variable Displacement Fuel Pump With Washed Actuation Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern aircraft fuel systems face challenges with thermal recirculation systems and require filtered fuel flow for actuation systems, necessitating components like fuel oil coolers, filters, and piping, which occupy space and increase complexity.
Innovation Solution
A dual variable displacement pump system with a bypass valve and washed actuation flow, eliminating thermal recirculation systems and barrier filters by modulating fuel flow to prevent overcooling and contamination, using a thermally efficient design with integrated pumps and valves to manage heat loads and provide cleaned fuel to actuation systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If thermal recirculation systems are eliminated to reduce component count and free space, then fuel system complexity and weight are reduced, but the fuel oil cooler cannot handle over-temperature heat loads at low burn flow conditions
Solution Approach 1:
The patent employs variable displacement pumps that dynamically adjust their displacement based on operating conditions. The actuation pump and main pump can vary their flow output to match thermal demands, eliminating the need for fixed thermal recirculation systems while maintaining proper temperature control across different flight regimes.
Solution Approach 2:
The system changes operational parameters by using variable displacement mechanisms to adjust fuel flow rates dynamically. This allows the fuel oil cooler to operate efficiently across a range of conditions without requiring thermal recirculation, as the pump output is optimized to prevent over-temperature heat loads at low burn flow conditions.
2Reliability
If filtered fuel flow is provided to actuation systems to eliminate contamination, then reliability is improved, but filters, piping, and supporting equipment are required
Solution Approach 1:
The patent combines the filtration function with the variable displacement actuation pump by incorporating a washable screen filter directly within the pump assembly. This integration eliminates the need for separate filter housings, piping, and supporting equipment while maintaining reliable filtered fuel flow to the actuation system.
Solution Approach 2:
The actuation pump performs its own filtration through the integrated washable screen, eliminating the need for external filtration systems. The pump's internal design allows it to self-filter the fuel it delivers, reducing overall system complexity while maintaining reliability.
3Use of energy by moving object
If variable displacement pumps are used to modulate fuel flow and prevent overcooling, then thermal efficiency is improved, but pump system complexity increases
Solution Approach 1:
The patent uses variable displacement pumps with adjustable mechanisms that allow dynamic control of fuel flow based on thermal demands. This dynamic capability improves thermal efficiency by preventing overcooling while the integration of control mechanisms within the pump assembly minimizes the increase in overall system complexity.
4Weight of moving object
If integrated pumps and valves are used to eliminate external plumbing, then weight and space are reduced, but manufacturing and assembly complexity increases
Solution Approach 1:
The patent integrates multiple functions (pumping, filtration, flow control) into single composite components. The actuation pump combines pumping and filtration functions, while the main pump integrates variable displacement and flow control capabilities. This merging reduces weight and eliminates external plumbing while the modular design facilitates standardized manufacturing and assembly processes.
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
This system reduces the need for thermal recirculation and filtration equipment, enhancing fuel system reliability, weight, and fuel capacity by providing a thermally efficient and filtered fuel flow without external plumbing, thus optimizing aircraft fuel systems.
Implementation Method 1
fuel oil cooler (FOC) in typical aircraft have over-temperature heat loads
Implementation Method 2
actuation filter (170) is a wash filter
Data Source
AI summary
A system includes an actuation pump sub-system (APS) with an inlet configured to feed fuel from a fuel source into the actuation pump sub-system, a first outlet configured for connecting the APS in fluid communication with an afterburner selector valve, a second outlet, and a third outlet for connecting the APS in fluid communication with an actuation system to supply washed fuel flow for actuation. A main pump and control sub-system (MPCS) has a main inlet connected in fluid communication with the supply line downstream of the second outlet of the APS, and a main outlet for supplying fuel to a downstream gas generator. An afterburner pump in fluid communication to supply an afterburner control. An afterburner selector valve (ASV) in fluid communication with the MPCS, the wash line, and the afterburner pump.