MODELLING A HYDROGEN FUELLED COMPOSITE CYCLE AEROENGINE

Paper in proceeding, 2024

A composite cycle engine (CCE) is an advanced cycle, air-breathing, jet engine that combines the power density of turbomachinery with the thermal efficiency of a piston engine. The piston engine is situated in the high-pressure part of the core, delivering shaft power to the high-pressure compressor. In the present paper, a methodology to thermodynamically assess the CCE will be presented, which includes the time-dependent modelling of the piston engine and its integration in a steady-state Joule-Brayton cycle thermodynamic model via an artificial neural networks surrogate. A good agreement can be found for the cross-validation of the baseline piston engine model, with the normalised root-mean-square error (NRMSE) over one engine cycle of less than 1% for pressure and temperature, and below 2% for mass and equivalence-ratio. Further, the hydrogen operation of the piston engine was validated against public experimental data. Three load cases were validated, with the NRMSE being 2% for low- and medium load.