The Study Of Numerical Simulation On Nanosecond Pulsed Dielectric Barrier Discharge In Nitrogen At Atmospheric Pressure

Atmospheric pressure nanosecond pulse discharge is an emerging atmospheric pressure low temperature plasma discharge technology. For its unique advantages and broad application prospects, the technology has drawn extraordinary attention of people. Compared to sinusoidal drives, studies have shown that nanosecond pulse discharge produced by atmospheric pressure plasma has many attractive advantages, for example, the higher of the peak current density, the electron density and the electron produce rate; the larger varieties and quantities of the active particles. What’s more, the activity of these particles is strong. Using this method we can achieve better results and higher efficiency when tackling the surface of the material. The plasma we obtained through this method has the qualities of good uniformity, large area and high electron temperature, and it is far away from the equilibrium state. However, so far, the numerical simulation of atmospheric pressure nanosecond pulse discharge research is mainly focused on the inert gas and mixed gas, while on other gas molecules, such as nitrogen, oxygen, nanosecond pulse Dielectric Barrier Discharge (DBD) research is very scarce. Therefore, the detailed reports in this field are difficult to see. In practical applications, the molecular gas discharge has a strong appeal to people, not only for the low cost, but for the adequate chemical species. However, the research people done on the molecular gas discharge mechanism of the nanosecond pulse discharge, discharge mode, and electric parameters’(repetition frequency, rising or falling, pulse width, etc.) impact on the discharge effect is limited and sporadic.In this work, we established a one-dimensional self-consistent fluid mechanics model, and did the simulation. The results show that the discharge mode of the nitrogen DBD excited by the nanosecond pulse is a typical atmospheric pressure glow discharge mode in a typical parameter range; which is different from the nitrogen DBD excited by the sinusoidal voltage. Nanosecond pulse driven dielectric barrier discharge can form a wide area of the plasma in the two discharge processes, and the processes are asymmetry; When the discharge current first reaches its peak, the peaks of the electron and the ion density appear near the cathode, and when the following discharge current peak arrives, the peaks of both the electron and the ion density appear near the poles. The characteristics of discharge change with the variation of discharge parameters. When increasing the pulse width, the secondary discharge current density becomes larger; Increasing the repetition frequency, the first discharge current density decreases; And when increasing the rising and falling time, the secondary discharge current density decreases; The increase of dielectric constant will cause the growth of the first and second discharge current density, but reduce the discharge time of the first discharge.