Numerical simulation of nonthermal atmospheric pressure plasma jet and comparison with experiments

This paper presents a computational study of point-to-plane atmospheric helium plasma discharge. We employed a two-dimensional, axisymmetric fluid model to investigate the time-dependent characters of the discharge. Helium with small amount of nitrogen (impurity) was used as the working gas. The gap distance between the two electrodes was varied from 1mm to 15mm. The magnitude of the applied voltage´s amplitude was in the range of 1kV~10kV, and the frequency was 10 kHz. The coupled continuity equations for particles and electron energy equation were solved with the Poisson´ equation using the finite element method with unstructured grids. Simulation results showed that the plasma needle operated as the corona discharge at low power and the mode transferred to glow discharge as the power surpassed certain critical value, and this value decreased either the frequency increased or the gap distance decreased. Furthermore, the simulation results were compared with the experimental results. The results showed that simulation results were in reasonable agreement with experiments.