Numerical investigation of the effect of high-voltage frequency on the density of RONS species in the air atmospheric pressure gas discharge

Abstract

In the last few decades, studies in various fields of plasma technology have expanded and its application in different processes has increased. Therefore, the achievement of a desirable and practical plasma with specific characteristics is of particular importance. The frequency of the applied voltage is one of the important factors that play a role in the physical and chemical characteristics. In this research, changes in the density of active species produced in an electrical discharge using a dielectric barrier and air working gas have been investigated, from a frequency of 500 Hz to 500 kHz, and by applying a constant voltage of 2 kV, have been investigated. For this purpose, 87 different reactions with specific collision cross-sections were defined in COMSOL Multiphysics. Other parameters, including current–voltage waveform, electric field, species density including \({\text{NO}}\),\({\text{OH}}\),\({\text{O}}_{2}^{ + }\),\({\text{O}}_{3}\), etc., were evaluated. The results show that under completely identical conditions, the electron temperature distribution changes with increasing applied frequency, and the density of reactive oxygen and nitrogen species (RONS) like (\({\text{NO}}\), \({\text{OH}}\), \({\text{O}}_{3}\),..) decreases, but \({\text{O}}_{2}^{ + }\) shows an increasing trend. It should be noted that the simulation results are in good agreement with the previous experimental and simulation reports. These results offer valuable insights into optimizing plasma parameters for different applications, potentially resulting in better treatment outcomes across a range of therapeutic domains.