• air-breathing electric propulsion
• composition
• ignition
• kinetic model
• plasma
• simulation

Air-breathing electric propulsion (ABEP) systems enable sustained operations at low orbital altitudes by utilizing atmospheric air as propellant. These engines include a plasma chamber where atmospheric gas is ionized and accelerated, requiring a detailed understanding of plasma processes under complex chemical conditions. This study investigates plasma ignition and steady-state behavior in ABEP systems through a zero-dimensional kinetic model for the ionization chamber.
The model considers over 800 reactions across categories such as electronic and vibrational excitation, ionization, dissociation, heavy-particle reactions, and electron attachment/recombination, addressing often-neglected processes like multiple ionization, and reactions with Argon. The computational framework, developed using ZDPlasKin and BOLSIG+, simulates plasma ignition, evolution, and steady-state properties over a range of operating parameters.
Simulation campaigns revealed the influence of mass flow rate, electron temperature, and species residence time on plasma density and composition, comparing orbital atmospheric mixtures with experimental conditions and evaluating Argon as an atomic Oxygen substitute. Results identified an ignition envelope defining plasma formation conditions and derived analytical laws to approximate ignition boundaries and plasma composition as function of plasma density, offering practical tools for engine modelling.
The results lay the foundation for future experimental validations and advancements in plasma modelling techniques, facilitating the development of efficient propulsion systems for low-altitude space missions.