Numerical modeling of ignition enhancement of CH4/O2/He mixtures using a hybrid repetitive nanosecond and DC discharge
Numerical modeling of ignition enhancement of CH4/O2/He mixtures using a hybrid repetitive nanosecond and DC discharge
复制标题
使用混合重复纳秒和直流放电对 CH4/O2/He 混合物点火增强进行数值模拟
DOI：
10.1016/j.proci.2018.05.106
复制
发表时间：
2019
影响因子：
3.4
通讯作者：
Yiguang Ju
中科院分区：
文献类型：
--
作者：
Xingqian Mao;Aric Rousso;Qi Chen;Yiguang Ju
采用ZDPlasKin-CHEMKIN混合方法研究了大气压下CH 4/O2/He混合气体中纳秒重复放电和直流放电混合放电对点火的增强作用。特别注意的是放置在使用不同的电场强度的甲烷和氧气的振动和电子激发的控制。提出并验证了等离子体点火动力学机制，该机制包括CH 4和O2的振动和电子激发反应以及O2的低温甲烷氧化途径（a1Δg）。结果表明，混合非平衡等离子体激发比单独的热加热和纳秒放电更有效地增强点火。与纳秒级放电中产生的O（1D）和O相比，混合放电中更有效地产生O2（a1Δg），并更有效地缩短点火延迟时间。振动激发的物种CH 4（ν）和O 2（ν）也产生，但主要有助于通过能量弛豫和气体加热点火增强。结果还表明，在一定的等离子体能量下，混合NSD/DC放电中e + O2 → e + O2（a1Δg）和e + O2→ e + O + O（1D）反应相互竞争氧的消耗，在点火增强中起相反的作用。对于一个给定的重复纳秒放电，有一个最佳的直流电场强度，具有最小的点火延迟时间，由于激发物种的选择性生产和电子密度的差异。这项工作提供了基本的理解混合放电的设计，以优化低温点火增强和燃料重整。
Ignition enhancement using a hybrid repetitive nanosecond and DC discharge is studied in CH4/O2/He mixtures at atmospheric pressure by using a hybrid ZDPlasKin-CHEMKIN method. Special attention is placed on the control of vibrational and electronic excitations of methane and oxygen using different electric field strengths. A plasma-ignition kinetic mechanism incorporating the reactions involving both vibrational and electronic excitations of CH4and O2as well as the low temperature methane oxidation pathways of O2(a1Δg) is developed and validated. The results show that the hybrid non-equilibrium plasma excitation is much more effective in ignition enhancement than thermal heating and the nanosecond discharge alone. O2(a1Δg) is generated more efficiently in the hybrid discharge and shortens the ignition delay time more effectively than O(1D) and O produced in the nanosecond discharge. Vibrationally excited species CH4(ν) and O2(ν) are also produced but mainly contribute to ignition enhancement via energy relaxation and gas heating. The results also show that e + O2→ e + O2(a1Δg) and e + O2→ e + O + O(1D) reactions compete with each other for oxygen consumption and play opposite roles in ignition enhancement in a hybrid NSD/DC discharge with a given plasma energy. For a given repetitive nanosecond discharge, there is an optimum DC electric field strength which has the minimum ignition delay time due to the selective production of excited species and the difference in electron density. This work provides fundamental understanding for the design of a hybrid discharge to optimize low temperature ignition enhancement and fuel reforming.
登录
查看更多内容
DOI：
10.1088/0022-3727/38/20/007
发表时间：
2005-09
期刊：
Journal of Physics D: Applied Physics
影响因子：
--
作者：
A. Hicks;Seth A. Norberg;P. Shawcross;W. Lempert;J. Rich;I. Adamovich
通讯作者：
A. Hicks;Seth A. Norberg;P. Shawcross;W. Lempert;J. Rich;I. Adamovich
DOI：
10.1098/rsta.2014.0341
发表时间：
2015-08
期刊：
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
影响因子：
--
作者：
A. Starik;Boris I. Loukhovitski;A. Sharipov;N. Titova
通讯作者：
A. Starik;Boris I. Loukhovitski;A. Sharipov;N. Titova
影响因子：
9.4
作者：
J. Lefkowitz;M. Uddi;B. Windom;G. Lou;Y. Ju
通讯作者：
J. Lefkowitz;M. Uddi;B. Windom;G. Lou;Y. Ju
影响因子：
4.4
作者：
Y. Ju;Wenting Sun
通讯作者：
Y. Ju;Wenting Sun
影响因子：
4.4
作者：
N. Tsolas;R. Yetter;I. Adamovich
通讯作者：
N. Tsolas;R. Yetter;I. Adamovich