Comparison of fluid and hybrid simulations of atmospheric pressure plasma jets in He/O₂ mixtures

Atmospheric pressure radio-frequency plasmas, such as the microplasma jet (μAPPJ), are essential in various scientific and industrial applications, e.g. plasma medicine, due to their ability to generate reactive oxygen and nitrogen species. For optimal use, understanding the interplay between electron dynamics, chemical reactions, and gas flow effects is crucial. Experimental approaches alone often fall short, necessitating numerical simulations.

This study assesses a fluid model to capture complex plasma behavior, focusing on non-local electron dynamics from Penning ionization and their impact on plasma characteristics. We compare results from the fluid model with a fluid Monte Carlo code (hybrid), using a helium (He) and oxygen (O₂) chemistry set, specifically a helium mixture with 0.5% of O₂.

The findings validate the accuracy of fluid simulations in replicating plasma dynamics, showing strong agreement with the Monte Carlo approach. While fluid codes may not fully capture all non-local electron effects, they still reliably describe μAPPJs. Minor differences, such as voltage amplitudes, do not diminish the effectiveness of fluid models. This study underscores the reliability of fluid models for applications requiring detailed descriptions of chemical and physical behavior.