Investigation of instabilities and striation structures in single filament dielectric barrier discharges in argon at atmospheric pressure

本项目拟用数值模拟的方法分析大气压介质阻挡放电中条纹结构的形成机制和自发模跃迁及不稳定性的物理原因。为此，一个自洽的流体动力学等离子体模型的时间和空间的二维描述的单灯丝介质阻挡放电在大气压下的氩气将被开发和应用的研究实验观察到的现象在考虑中的放电。特别是，它将澄清哪些物理过程是负责实验观察到的放电模式的形成和条纹的发生沿着放电通道。此外，还分析了掺氧剂对放电特性的影响。新的漂移扩散近似的电子发展和建立的动力学方法的应用，使人们有可能研究的非局域电子能量输运的大气压介质阻挡放电中的条纹的产生的影响，第一次。该项目的主要目标是通过基于实验分析设计的参数研究，对外部放电参数（如电压幅度和频率）的影响以及气体杂质对放电稳定性的影响进行更深入的物理了解。这样，就可以优化输入参数，控制不同的放电模式，并使它们可用于应用。

In the planed project the formation mechanisms of striated structures and the physical reasons for spontaneous mode transitions and instabilities in dielectric barrier discharges at atmospheric pressure are analysed by means of numerical modelling. For this, a self-consistent hydrodynamic plasma model for the temporal and spatially two-dimensional description of a single filament dielectric barrier discharge in argon at atmospheric pressure will be developed and applied for the investigation of phenomena observed experimentally in the discharge under consideration. In particular, it will be clarified which physical processes are responsible for the formation of the experimentally observed discharge modes and the occurrence of striations along the discharge channel. In addition, the influence of oxygen admixtures on the discharge characteristics is analysed. The novel drift-diffusion approximation for electrons developed previously and the application of established kinetic methods make it possible to study the effect of nonlocal electron energy transport on the generation of striations in dielectric barrier discharges at atmospheric pressure for the first time. The key objective of the project is to gain a deeper physical understanding of the influence of external discharge parameters, such as voltage amplitude and frequency, as well as the impact of gas impurities on the stability of the discharge by means of parametric studies based on a design of experiment analysis. With this, it becomes possible to optimize the input parameters, to control the different discharge modes and to make them usable for applications.