Plasma-induced flow instabilities in atmospheric pressure plasma jets

Journal Article · 11 September 2017 · Applied Physics Letters

DOI: https://doi.org/10.1063/1.4996192 · OSTI ID:1535336

Lietz, Amanda M. ^[1]; Johnsen, Eric ^[2]; Kushner, Mark J. ^[2]

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1. Univ. of Michigan, Ann Arbor, MI (United States); DOE/OSTI
2. Univ. of Michigan, Ann Arbor, MI (United States)

Pulsed plasma excitation of rare gases flowing into air has been shown to impact the stability of the flow in non-equilibrium atmospheric pressure plasma jets (APPJs). In this paper, the results from a numerical modeling investigation of the stability of a round He APPJ with a powered electrode exposed to the gas flow are discussed. Localized gas heating at the powered electrode occurs on the time scale of the voltage pulse, tens to 100 ns, which is short compared to the fluid timescales. An acoustic wave propagates from this heated, expanding gas and exits the jet. The wave disturbs the shear layer between the He and surrounding humid air, exciting a shear instability which grows downstream with the flow and increases the mixing of the humid air into the He. The effects of the eddy-dominated flow on ionization wave (IW) propagation in an APPJ were investigated. The IW followed the regions of the highest helium concentration, resulting in an increased production of NO, HO₂, and NO₂.

• Research Organization: Univ. of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: SC0014132
• OSTI ID: 1535336
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 11 Vol. 111; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English