Online Spectroscopic Chemical Diagnostics for Thermally Stressed Fuel Flows

ABSTRACT: The limits of high-performance aircraft continue to be pushed, requiring more capacity from thermal management systems as hydraulic, mechanical, and pneumatic power systems are replaced with electrical components. Rejecting this heat to the fuel can lead to composition changes and the production of insolubles and surface deposits via pyrolysis and oxidation at elevated fuel temperatures, especially at walls and hot spots. As such, it is important to understand and monitor online the thermal degradation processes.A few trace compounds have been identified as critical in the thermal oxidative chemical process including hydroperoxides, reactive sulfur compounds, polar organic compounds, trace metals, and dissolved oxygen. Currently, there is no way to measure these compounds in real-time at aircraft-relevant conditions or determine the onset of thermal instability. Mainstream Engineering proposes a spectroscopic approach using solid-state, fiber-coupled components to determine bulk properties and trace indicators of thermal oxidation through chemometric analysis. Phase I will result in a high-fidelity integration of components in the laboratory. Phase II will include testing a prototype demonstrator on the Advanced Reduced Scale Fuel System Simulator as well as development and execution of technology transition strategy.; BENEFIT: Next-generation aircraft will require thermal management systems (TMSs) capable of dissipating thermal loads of 100s to 1000s of kilowatts. These thermal loads exceed the capacity of current tactical aircraft TMSs. The proposed fuel condition monitor (FCM) will extend the capability next-generation TMSs that sink heat to the fuel, thereby supporting the More Electric Aircraft (MEA) initiative. TheFCM will support future military and military aircraft. The underlying technology also has applications for ground-based fuel testing. Mainstream Engineering, a two-time Tibbetts Award winner with a 95% commercialization achievement index, is well-poised to commercialize this technology having brought over 30 commercial and military products to the market.