Calculation of the net emission coefficient of an air thermal plasma at very high pressure
Calculation of the net emission coefficient of an air thermal plasma at very high pressure
复制标题
极高压力下空气热等离子体的净排放系数的计算
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Gleizes
中科院分区：
文献类型：
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作者：
T. Billoux;Y. Cressault;P. Teulet;A. Gleizes
本文的目的是对高压空气等离子体在局部热力学平衡(LTE)中出现的现象作出准确的评价。过去，我们已经计算了大气压和30KK以下温度(分子贡献限制在10KK)下的空气混合物的净发射系数。不幸的是，由于等离子体的非理想性，高压的存在不允许我们使用这个数据库(维里埃尔和德拜修正，能量切断…)，并且由于分子反应向较高温度的显著转移。因此，本文对以前的工作进行了改进，在合成算法中考虑了高压修正，以考虑压力效应，并使用更新的数据库重新计算了等离子体辐射(原子线和连续体，分子连续体和分子带)的所有贡献。特别注意计算了所有主要分子带系对辐射的贡献：O2(Schumann-Runge)，N2(VUV，第一和第二正)，NO(IR，β，γ，δ，∊)和N2+(第一负和Meinel)。用逐行方法计算了30KK和100bar的离散原子谱线和分子能带辐射。通过将我们的综合发射强度与已发表的结果进行比较，在光薄等离子体和1bar气压的情况下，验证了该数据库的有效性。最后，这项工作表明了在高压(带和连续谱)下将分子辐射数据库扩展到15kK的必要性，因为它们在高温下的相应贡献是不能忽略的。
The aim of this paper is to present an accurate evaluation of the phenomena appearing for high pressure air plasmas supposed to be in local thermodynamic equilibrium (LTE). In the past, we already calculated the net emission coefficient for air mixtures at atmospheric pressure and for temperatures up to 30kK (molecular contribution being restricted to 10kK). Unfortunately, the existence of high pressures does not allow us to use this database due to the non-ideality of the plasma (Viriel and Debye corrections, energy cut-off …), and due to the significant shifts of molecular reactions towards upper temperatures. Consequently, this paper proposes an improvement of our previous works with a consideration of high pressure corrections in the composition algorithm in order to take into account the pressure effects, and with a new calculation of all the contributions of the plasma radiation (atomic lines and continuum, molecular continuum, and molecular bands) using an updated database. A particular attention is paid to calculate the contribution of all the major molecular band systems to the radiation: O2 (Schumann–Runge), N2 (VUV, 1st and 2nd positive), NO (IR, β, γ, δ, ∊) and N2+ (1st negative and Meinel). The discrete atomic lines and molecular bands radiation including the overlapping are calculated by a line-by-line method up to 30kK and 100 bar. This updated database is validated in the case of optically thin plasmas and pressure of 1bar by the comparison of our integrated emission strength with the published results. Finally, this work shows the necessity to extend the molecular radiation database up to 15kK at high pressure (bands and continuum) since their corresponding contributions could not be neglected at high temperature.