The Impact of Intermolecular Interactions in Sustainable Aviation Fuels on Turbine Engine Parameters

This study investigates the effect of the concentration of sustainable jet fuel components on selected physicochemical properties of blends with fossil Jet A-1 fuel, as well as on parameters characterizing the combustion process in aircraft turbine engines. The analyzed physicochemical properties were density, net heat of combustion, and fractional composition (50% recoverey temperature and viscosity at −20 °C) of the fuel blends. The combustion process was examined using test rigs equipped with GTM 140 and DGEN 380 engines operated at different rotational speeds. For each engine speed, the fuel mass flow rate and the combustion chamber temperature were determined. The functions mf = Ae^(−Ea/RT) were derived, corresponding to the kinetic equations of the complete combustion reaction chain. The (Ea/R)mf values obtained using the trend line method for the GTM 140 engine were found to be linearly related to those obtained for the DGEN 380 engine. A deviation from linearity was observed for blends containing 5% of various synthetic components. These findings support a new hypothesis that the same intermolecular interactions between liquid fuel components that account for the non-additivity of physicochemical properties also contribute to the parameters of combustion kinetics in turbine engines. Tests on the turbine engine provided preliminary validation of this hypothesis.