| 引用本文: | 瞿章华,沈建伟,阮立明.不同的扩散模型对再入体等离子体鞘电子密度分布的影响.[J].国防科技大学学报,1993,15(3):31-37.[点击复制] |
| Qu Zhanghua,Shen Jianwei,Ruan Liming.The Effects of Different Diffusion Models on Electron Distribution of Plasma Sheath about Reentry Bodies[J].Journal of National University of Defense Technology,1993,15(3):31-37[点击复制] |
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| 不同的扩散模型对再入体等离子体鞘电子密度分布的影响 |
| 瞿章华, 沈建伟, 阮立明 |
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(航天技术系)
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| 摘要: |
| 本文研究不同的扩散模型对再入体等离子体鞘电子密度分布的影响。由于电子和离子的质量相差三个量级以上，电子的浓度扩散速度比离子大得多，引起正负电荷分离。由此产生的诱导电场又阻碍带电粒子的扩散运动。本文同时考虑这二种影响扩散的因素，得到了非平衡等离子体鞘带电粒子分布的数值解，并与准中性模型、双极扩散模型等其它三种近似模型进行了比较。计算表明：流场的大部份区域满足等离子体准中性假定，但在物面和激波附近存在电荷分离较明显的薄层，其厚度约为Debye 屏蔽长度的量级。这种边界效应对中性粒子的分布影响甚微，但对带电粒子的分布则产生一定的影响。由此可以判断各种扩散模型的适用性。 |
| 关键词: 高超声速，电荷分离，扩散，等离子体 |
| DOI： |
| 投稿日期：1993-05-04 |
| 基金项目: |
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| The Effects of Different Diffusion Models on Electron Distribution of Plasma Sheath about Reentry Bodies |
| Qu Zhanghua, Shen Jianwei, Ruan Liming |
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(Department of Aerospace Technology)
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| Abstract: |
| The effects of different diffusion models are studied for electron distribution of plasma sheath about reentry bodies. The diffusion velocity of electron due to density gradients is much larger than that of ions because the weight of the electrons is about three orders in magnitude less than that of the ions. Both the charge separation and its induced electric field exert an influence on the particle diffusion. The electron density distribution is obtained with numerical solution under these conditions. The results are compared with other diffusion models such as the quasi-neutral model，ambipolar diffusion model，etc. It shows that the quasi-neutral assumption is valid in most region of the flowfield，but the charge separation occurs near the body surface. The dimension of the thin layer with charge separation is in the same order of Debye shield length. The electric particle distribution is influenced somewhat by the boundary effects although the neutral moleculars and atoms are unaffected. The applicability of these diffusion models is judged through their comparaision of the numerical solution. |
| Keywords: hypersonic,diffusion,plasma,charge separation |
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