Numerical investigation on plume expansion, components evolution and ionization of polytetrafluoroethylene (PTFE) irradiated by nanosecond laser

Abstract

To investigate the plume expansion, components evolution and ionization in the laser ablation pulsed plasma thruster, which is difficult to obtain from experiments, the non-Fourier heat conduction model, fluid dynamics model and thermochemical model are established. The non-Fourier heat conduction model is established to calculate the propellant ablation, taking into account temperature dependent material properties, phase transition, depolymerization of polytetrafluoroethylene propellant, the reflection of the laser beam at the surface of the propellant, and non-Fourier effect. The fluid dynamics model is established to calculate the plume expansion, taking into account plume absorption and shielding. The thermochemical model is established to calculate the components evolution and ionization, taking into account nine chemical and ionization reactions with 12 components. By coupling the three models, the thermochemical characteristics, plume expansion and ionization of polytetrafluoroethylene irradiated by a nanosecond laser are numercially calculated.