THERMO-OXIDATIVE STABILITY UNDER HIGH REYNOLDS NUMBER FLOW: AN ALTERNATIVE METHODOLOGY FOR THE DEVELOPMENT OF AVIATION KEROSENE

Aviation fuel (kerosene) is not only employed as energy source for aircraft propulsion, but also plays an important role as coolant and lubricant on various aircraft systems. As a coolant, the fuel undergoes heating and cooling cycles in lines and heat exchangers. Heating of the fuel triggers chemical reactions on liquid phase, and the products of these reactions can contain insoluble chemical species that may react with metal surfaces and form deposits, which increases the risk of clogging valves, filters, and combustion chamber injectors. Thermal stability is the quality of the fuel be subjected to heating periods without presenting expressive degradation. Thermal stability requirements must be met to attain certification for use in existing and new aircraft, resulting in a complex and costly process for the development of new fuels. In this study, the thermo-oxidative stability of Jet A-1 aviation fuel was investigated using the High Reynolds Thermal Stability Test (HiReTS Test). The Reynolds number of the flow varies from 2000 at the inlet of the test section to 14000 at the outlet, which are closer to the application then the conditions of the JFTOT standard test. Tests were carried out for five fuel samples, two of which were deemed thermally stable while the remaining three showed low stability. In conclusion, the method is suitable for evaluating the thermo-oxidative stability of aviation fuels, still using relatively small amounts of fuel, which can be very advantageous during fuel development.