Numerical Study of Nonequilibrium Seed-Free Argon Plasma Mangetohydrodynamic Generator using Collisional-Radiative Model,
Numerical Study of Nonequilibrium Seed-Free Argon Plasma Mangetohydrodynamic Generator using Collisional-Radiative Model,
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使用碰撞辐射模型的非平衡无种子氩等离子体磁流体动力发生器的数值研究，
DOI：
10.1109/tps.2021.3059440
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Y. Okuno
中科院分区：
文献类型：
--
作者：
T. Fujino;S. Ito;Y. Okuno
为了研究辐射跃迁对非平衡态无籽晶氩等离子体磁流体动力学（MHD）发生器性能的影响，采用碰撞辐射（C-R）模型，在双温、低磁雷诺数MHD近似下，对45个离散有效电子激发能级的中性氩原子、单电离氩离子和自由电子进行了数值模拟.此外，在C-R模型中引入了一个逃逸因子来考虑基态中性原子的辐射俘获效应。利用所开发的技术，我们计算了非平衡无籽晶氩等离子体磁流体发电机的性能特性。数值结果表明，发生器性能随着逃逸因子的减小而提高，即，辐射跃迁到中性原子基态的光学厚度增加。数值结果还表明，对于中性原子到基态的辐射跃迁，当逃逸因子小于等于0时，发生器的性能与逃逸因子为0时的性能基本相同。此外，现实的逃逸因子值的谐振线的发电通道进行了评估，使用一个众所周知的估计模型。因此，估计值为。我们还表明，在这样的相对光学厚的等离子体的情况下，碰撞（C）模型和广泛使用的全球电离-复合率模型，没有明确考虑电子激发态中性原子可以重现发电机性能预测的C-R模型具有相对较好的精度。
To examine the influence of radiative transitions on the performance of nonequilibrium seed-free argon plasma magnetohydrodynamic (MHD) generators, we developed MHD numerical simulation technique with a collisional-radiative (C-R) model, where neutral argon atoms with 45 discrete effective electronic excitation levels, singly ionized argon ions, and free electrons were considered under a two-temperature, low-magnetic Reynolds number MHD approximation. Furthermore, a so-called escape factor was implemented in the C-R model to consider the effects of radiation trapping by ground-state neutral atoms. Using the developed technique, we computed the performance characteristics of a nonequilibrium seed-free argon plasma MHD generator. The numerical results showed that the generator performance gets higher as the escape factor decreases, i.e., the optical thickness for radiative transitions to the ground state of neutral atoms increases. The numerical results also suggested that when the escape factor isor less, the generator performance is almost the same as that for the escape factor of 0 corresponding to completely optical-thick plasma case for the radiative transitions to the ground state of neutral atoms. Furthermore, realistic escape factor values for resonance lines in the power generation channel were evaluated using a well-known estimation model. Consequently, the estimated values had the order of. We also showed that under such relatively optically thick plasma cases, a collisional (C) model and a widely used global ionization-recombination rate model with no explicit consideration of electronically excited-state neutral atoms can reproduce the generator performance predicted by the C-R model with relatively good accuracy.