微波大气压等离子体射流的多物理场模拟及其机理研究

微波大气压等离子体射流因其无极放电，电离度高，活性粒子多等优点，在生物医学，材料处理，能量转化及环境保护等领域中具有巨大的应用潜力。然而微波在大气压下诱导气体放电产生等离子体射流的过程极其复杂，目前还缺乏快速且准确的数值模拟办法，而且微波与等离子体射流相互作用的机理也不够清晰。这导致了微波大气压等离子体射流源普遍存在能量利用率低，放电稳定性差，等离子体处理面积小，微波辐射安全性不清楚等问题，极大地限制了其产业化应用。针对这些问题，本项目将基于前期设计的微波大气压等离子体射流源，创新地采用双极化扩散理论并结合尺度变换法，研究三维空间中微波激发混合气体放电的多物理场模拟暨其数学模型的快速算法。然后综合实验观测，理论分析与数值模拟，研究微波沿等离子体射流的传播，辐射与损耗特征，以及等离子体射流受微波的影响。本项目能为微波大气压等离子体射流源的优化设计及其应用提供快速准确的模拟方法和理论支撑。

Microwave atmospheric pressure plasma jet, with its specific advantages of electrodeless discharge, high ionization degree and abundant active particles, has gained great potential in biomedical applications, material processing, energy conversion and environmental protection. However, the process of plasma jet induced by microwave at atmospheric pressure is very complicated. At present, there is still a lack of fast convergent and accurate numerical models to simulate it. Besides, the interaction mechanism between the microwave and the plasma jet remains unclear as well. As a result, microwave atmospheric pressure plasma jet sources currently still surfer from a low energy efficiency, a small plasma treatment area, poor discharge stability and uncertain microwave radiation safety. To solve these problems, based on our previously designed microwave atmospheric pressure plasma jet sources, this project will adopt the ambipolar diffusion theory and the scale transformation method in an innovative way to study the multi-physical model of gas mixture discharge in 3D space and its fast algorithm. Then, with the combination of experimental observation, theoretical analysis and numerical simulation, the propagation, radiation and dispersion characteristics of the microwave along the plasma jet, as well as the influence of microwave on the plasma jet are studied. The results obtained in this project can provide theoretical support and numerical modelling method for the optimization design and the applications of microwave atmospheric pressure plasma jet sources.