Numerical Study of the Propagation Characteristics of He + Ar + O2 Atmospheric Pressure Plasma Jet

A two-dimensional axisymmetric fluid model was employed to investigate the influence of varying argon volume fraction in the working gas on the propagation characteristics and reactive species generation of pulsed He + Ar + O₂ plasma jet. The results demonstrate that at an argon volume fraction of 10%, the Penning effect between He and Ar is most pronounced, and the electron temperature and electron density of the He + Ar + O₂ plasma jet reach their maxima. The electron temperature in the upstream region of the jet front dissipates more slowly due to Penning ionization between helium and argon. At the end of the pulse, higher—temperature electrons accumulate near the tube nozzle in a triangular distribution. During propagation from the tube into open air, the ionization wave of the He + Ar + O₂ plasma jet evolves from a hollow ring to a solid bullet shape, with the highest bullet velocity observed at an argon volume fraction of 10%. The densities of Ar⁺ and Ar^* reach their maxima at argon volume fractions of 10% and 30%, respectively, while the densities of He⁺ and He^* decrease monotonically as the argon volume fraction increases. Notably, the ozone generation efficiency is maximized at an argon volume fraction of 10%.