Thermal-chemical instability of weakly ionized plasma in a reactive flow

• Published in: Journal of physics. D, Applied physics Applied physics, 2019-11, Vol.52 (48), p.484001
• Main Authors: Zhong, Hongtao, Shneider, Mikhail N, Mokrov, Mikhail S, Ju, Yiguang
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; hydrogen combustion; plasma chemical instability; plasma thermal instability; reactive flow; weakly ionized plasma
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/1361-6463/ab3d69

The control of plasma instability of weakly ionized plasma in a reactive flow is of great importance in plasma-assisted combustion, catalysis, fuel reforming and material synthesis. In this work, we propose a new concept of plasma chemical instability and analyze the mechanisms and impact of plasma chemical instability on the transition from a uniform discharge to a contracted state of a self-sustained glow discharge in a reactive H2-O2-N2 mixture. A one-dimensional numerical model for plasma chemical instability was developed which accounted for convective heat loss, Joule heating of plasma, and major non-equilibrium plasma-assisted combustion kinetic pathways including electron-impact ionization, vibrational energy transfer, electron attachment, combustion reactions, and heat release. The results showed that plasma chemical instability significantly modified the onset plasma current of plasma thermal instability. Specifically, the critical condition of the instability transition was strongly influenced by electron-impact reactant ionization, electron attachment to oxygen, endothermic/exothermic chemical reactions, and the formation of reaction products.