Hybrid Kinetic–RQL Exergy Analysis of a CFM56-7B Turbofan Fueled with Jet-A1 and AtJ-SPK

Sustainable aviation fuels (SAFs) are essential for decarbonizing aviation, yet their impact on in-engine combustion irreversibilities and transient chemical behavior remains poorly captured by conventional "black-box" thermodynamic models. In this study, a hybrid thermodynamic–kinetic framework is applied to investigate the exergetic performance of a CFM56-7B turbofan engine core operating with conventional Jet-A1 and alcohol-to-jet synthetic paraffinic kerosene (AtJ-SPK). A zero-dimensional, station-based exergy analysis is first performed for the high-pressure compressor, combustor, and high-pressure turbine at design-point conditions. Fuel-specific chemical-kinetic effects are then introduced through homogeneous reactor and perfectly stirred reactor (PSR) simulations implemented with HyChem fuel surrogates in Cantera. PSR-derived kinetic results are employed as an interpretive layer to rationalize fuel-dependent combustor irreversibilities, rather than for direct numerical correction of the exergy balances. The results show that the component-level exergetic efficiencies remain within a narrow range for both fuels, while the combustor dominates the total core exergy destruction. AtJ-SPK exhibits shorter low-temperature ignition delays and lower carbon monoxide and unburned hydrocarbon levels under fuel-rich conditions. The proposed framework enables a consistent comparison of Jet A1 and AtJ-SPK fuels beyond complete-combustion assumptions.