The effect of humidity on hydroxyl and ozone production by nanosecond discharges

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• 作者：Daniel Singleton^a ; ¹ ; ^{dsinglet@usc.edu" class="auth_mail" title="E-mail the corresponding author} ; Campbell Carter^b ; Scott J. Pendleton^a ; ² ; Christopher Brophy^c ; Jose Sinibaldi^c ; ³ ; John W. Luginsland^d ; ⁴ ; Michael Brown^b ; Emanuel Stockman^e ; Martin A. Gundersen^a
• 关键词：Non-equilibrium plasma ; Nanosecond pulsed power ; Transient plasma ignition ; Planar laser induced florescence ; Hydroxyl ; Ozone
• 刊名：Combustion and Flame
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：167
• 期：Complete
• 页码：164-171
• 全文大小：1998 K

文摘

The interplay of humidity and non-equilibrium, transient plasma was studied via ignition experiments in a C₂H₄–air mixture, concentration measurements in humid air, and detailed simulations. Hydroxyl (OH) and ozone (O₃) produced via non-equilibrium plasma were characterized in a flowing H₂O–air mixture at atmospheric pressure with varying the levels of humidity using planar laser-induced fluorescence (PLIF) and UV absorption, respectively. The OH, which was created in the discharge streamers, peaked at a concentration of ∼5 × 10¹⁴/cm³ and then decayed below 1 × 10¹⁴/cm³ after ∼100 µs. O₃, which is long lived, peaked at a concentration of 1.4 × 10¹⁵/cm³. An increase in humidity from g" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0010218016000729&_mathId=si1.gif&_user=111111111&_pii=S0010218016000729&_rdoc=1&_issn=00102180&md5=ecba2525a842d563aa7af6c353dd5207" title="Click to view the MathML source">X_H2Ogif" overflow="scroll">XH2O ≈ 0.2% to 1% resulted in a monotonic increase in the concentration of OH and a 67% decrease in that of O₃. Zero-dimensional Boltzmann modeling of non-equilibrium plasma discharges in humid air showed qualitative agreement with these results and points to the decrease in O concentration (with increasing humidity) as the reason for the decreased O₃ concentration. In spite the dramatic decline in g" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0010218016000729&_mathId=si2.gif&_user=111111111&_pii=S0010218016000729&_rdoc=1&_issn=00102180&md5=7ffd0fea4742a68fda461afc14d7533e" title="Click to view the MathML source">X_O3gif" overflow="scroll">XO3 with increased humidity, there was no strong commensurate effect on ignition and flame propagation in C₂H₄–air mixtures: Peak pressure rise rate was at its maximum value at g" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0010218016000729&_mathId=si1.gif&_user=111111111&_pii=S0010218016000729&_rdoc=1&_issn=00102180&md5=ecba2525a842d563aa7af6c353dd5207" title="Click to view the MathML source">X_H2Ogif" overflow="scroll">XH2O = 1% but was only 25% less at g" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0010218016000729&_mathId=si1.gif&_user=111111111&_pii=S0010218016000729&_rdoc=1&_issn=00102180&md5=ecba2525a842d563aa7af6c353dd5207" title="Click to view the MathML source">X_H2Ogif" overflow="scroll">XH2O = 5%.