大气压冷等离子体射流动力学的数值研究

As a new type of low temperature plasma sources, cold atmospheric pressure plasma jets have recently been of significant interest for a large number of emerging applications. To uncover the fundamental mechanisms of plasma jets, this project intend to investigate the basic dynamics of plasma jets by constructing a suitable physical model for atmospheric pressure plasma jets. A complete fluid model describing the cold plasma jets is proposed and used to investigate the formation, propagation, and inhibition of the plasma bullets by taking the interaction between the plasma and the gas flow into account; To investigate the role of the control parameters such as gas flow, applied voltage, driving frequency, electrode configuration in the process of plasma jet propagation; To investigate the relationship between the discharge region and the jet region; To investigate the characterizes of plasma jets in different operating modes; To investigate the interaction between plasma jets; To make sure the forming mechanism of self-organized patterns in the plasma jet with large size by analyzing the theory of self organization and bifurcation. These results will promote the development of the cold atmospheric pressure plasma jets and the numerous applications, especially the new emerging biological and environmental engineering.

作为一种新兴的低温等离子体发生技术，大气压冷等离子体射流成为目前国际上等离子体科学与技术领域内的研究热点之一。本项目拟通过完善现有的等离子体流体模型，采用数值模拟的方法研究大气压冷等离子体射流产生、传播以及相互作用等根本性问题。考虑气流场和电场之间的相互作用，建立完整的大气压冷等离子体射流模型，研究气流、电压、频率、电极结构等外部参量在冷等离子体射流中所起的作用；分析放电区和射流区之间的相互关系；研究不同放电模式下的射流特性；研究多个等离子体射流之间的相互作用形式；数值研究较大尺寸冷等离子体射流中的自组织斑图结构，并利用非线性领域中的自组织原理以及分岔理论，从非线性动力学角度分析射流斑图的形成原理。该研究结果将对推动大气压冷等离子体射流的发展及其在众多领域尤其是新兴的生物工程以及环境工程等领域内的应用均具有重要意义。

建立了一个描述大气压非平衡等离子体射流的物理模型，该模型包含了等离子体模块、中性气流模块、动力学模块以及外电路方程模块等四个模块。采用建立的等离子体射流模型，数值模拟了单个等离子体射流的产生和传播过程，同时研究了电压大小、电极形状、电介质等放电参数对射流放电性质的影响。分析获得了放电区与射流区之间的相互作用关系。数值研究了两个相互独立的射流之间的相互作用过程，探究了射流与不同界面的作用机理。获得了介质阻挡放电形式下的两种稳定斑图放电模式：简单斑图和超点阵斑图。同时利用唯象的反应扩散模型，理论分析了气体放电中斑图放电的形成机理以及相应的分岔过程。.在Physics of Plasams，J Phys. D: Appl.Phys等国内外权威性杂志上发表论文12篇。本项目成果不仅推动了大气压冷等离子体射流的发展，而且扩展了气体放电等离子体在非线性动力学方面的研究。其中关于超点阵放电斑图的数值研究被选为Physics of Plasams杂志当期的封面文章。