Influence of gas flow velocity on the transport of chemical species in an atmospheric pressure air plasma discharge

• Published in: Applied physics letters 2017-03, Vol.110 (13)
• Main Authors: Hasan, M. I., Walsh, J. L.
• Format: Article
• Language: English
• Subjects: Air plasma; Applied physics; Atmospheric pressure; Chemical reactions; Density; Flow velocity; Gas flow; Mass transport; Mathematical models; Organic chemistry; Plasma; Plasma chemistry; Plasma jets; Spatial distribution
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4979178

This paper reports on a numerical study of the transport of reactive chemical species generated in an atmospheric-pressure air plasma discharge under the influence of a high velocity flowing gas. Using a 1D air plasma model, it is shown that the reactive species transported downstream of the discharge region can be categorized into three distinct groups based on their spatial distribution: (i) decaying downstream species, (ii) increasing downstream species and (iii) variable density species, where the density is a function of both spatial position and gas flow velocity. It is demonstrated that the gas flow velocity influences the dominant chemical reactions downstream of the discharge region, noticeably altering the composition of several key reactive chemical species transported to a given downstream location. As many emerging applications of atmospheric pressure plasma are driven by the flux of reactive chemical species, this study highlights the importance of gas flow velocity, not only as a means to enhance mass transport but also as a means to manipulate the very nature of the reactive plasma chemistry arriving at a given location.