Interleaved Flow Impingement Elements for Fuel Deoxygenation
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Solution Overview
Problem
Current systems for deoxygenating jet fuel in aircraft engines are unable to efficiently process high flow rates in a compact and lightweight form, failing to sufficiently lower dissolved oxygen concentrations to prevent coke formation at elevated temperatures, which can impair fuel system functionality.
Innovation Solution
A deoxygenator system with interleaved flow impingement elements that enhance contact between fuel flow and an oxygen permeable membrane, breaking up the fuel flow boundary layer to increase oxygen transport, allowing for efficient oxygen removal while maintaining laminar flow and minimizing pressure drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flow impingement elements are added to enhance oxygen transport, then mass transport of dissolved oxygen increases, but device complexity and pressure drop increase
Solution Approach 1:
The fuel passage is segmented into multiple flow channels by interleaved flow plates with flow impingement elements. Each flow plate creates discrete flow paths that systematically enhance mass transport through controlled flow impingement, breaking down the complex flow pattern into manageable segments while maintaining overall effectiveness
Solution Approach 2:
Flow impingement elements extend into the flow path from the flow plates, adding a third dimension to the otherwise planar flow structure. This dimensional addition creates flow impingement zones that enhance mass transport without requiring increased flow path length, thus improving productivity without proportional increases in device complexity
2Productivity
If flow path length is increased to enhance contact between fuel and membrane, then oxygen removal efficiency improves, but size and weight of the system increase
Solution Approach 1:
Flow impingement elements create curved and turbulent flow patterns within the fuel channels, replacing straight laminar flow with three-dimensional flow trajectories. This curvature and turbulence enhance mixing and mass transport efficiency, allowing sufficient oxygen removal in shorter flow path lengths without increasing system size or weight
Solution Approach 2:
Interleaved flow plates with periodic flow impingement elements create repeating flow disruption zones along the fuel passage. This periodic action continuously renews the boundary layer and enhances mass transport through the membrane without requiring a proportionally longer flow path, thus improving oxygen removal efficiency while controlling system dimensions
3Productivity
If flow velocity is increased to enhance mass transport, then oxygen removal rate improves, but fuel flow pressure drop increases
Solution Approach 1:
Flow impingement elements create dynamic flow patterns with localized high-velocity zones followed by recirculation regions. The flow velocity is dynamically modulated through the interleaved flow plates, maintaining high mass transport in impingement zones while allowing pressure recovery in subsequent regions, thus improving oxygen removal rate without excessive overall pressure drop
Solution Approach 2:
The system employs porous flow plates with flow impingement elements that distribute flow uniformly across multiple channels. This porous structure reduces flow resistance and pressure drop compared to solid barriers, while still achieving the necessary flow disruption and mixing enhancement for improved oxygen removal rate
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 system effectively reduces oxygen concentrations to suppress coke formation, enabling fuel to be heated to higher temperatures without significant increases in size or weight, thus improving fuel system performance and efficiency.
Implementation Method 1
removes oxygen from jet fuel by producing an oxygen partial pressure gradient across a membrane permeable to oxygen
Implementation Method 2
The flow impingement elements break up the boundary layer of the fuel flow to enhance the transport of oxygen from the core of the fuel flow to the oxygen permeable membrane surface
Data Source
AI summary
A fuel system for an energy conversion device includes a deoxygenator system with a multitude of flow impingement elements which are interleaved to provide a fuel channel with intricate two-dimensional flow characteristics. The flow impingement elements break up the boundary layers and enhance the transport of oxygen from the core of the of the fuel flow within the fuel channel to the oxygen permeable membrane surfaces by directing the fuel flow in a direction normal to the oxygen permeable membrane. The rapid mixing of the relatively rich oxygen core of the fuel with the relatively oxygen-poor flow near the oxygen permeable membrane enhances the overall removal rate of oxygen from the fuel. Because this process can be accomplished in fuel channels of relatively larger flow areas while maintaining laminar flow, the pressure drop sustained is relatively low.