低功率氮氢电弧加热发动机非平衡数值模拟

发布时间：2018-02-16 08:59

本文关键词： 氮氢电弧加热发动机非平衡数值模拟化学动力学电推进　出处：《中国空间科学技术》2016年03期 　论文类型：期刊论文

【摘要】：文章对低功率氮氢电弧加热发动机进行了双温度化学非平衡数值模拟研究,模型中包含总的能量方程和电子能量方程,等离子体组分包括分子、原子、离子和电子等7个组分,采用的化学动力学模型中包含了氮氢组分解离、电离等重要的动力学过程,气体的物性根据当地的组分和温度实时计算。通过计算获得了发动机内部气体温度及各组分数密度分布。结果表明,发动机轴线附近等离子体接近热力学平衡,而在发动机阳极壁面电弧贴附区域等离子体明显偏离热力学平衡;计算获得的组分分布表明电弧加热发动机内存在反混合过程,即发动机内各组分分布与入口浓度分布明显不同。氢组分由发动机中心到阳极壁面沿径向呈现先减小后增大的趋势;而氮组分的浓度分布趋势与氢组分相反;进一步的分析表明,发动机内各组分的扩散主要受到气体解离和电离过程引起的浓度梯度所驱动。
[Abstract]:In this paper, the two-temperature chemical non-equilibrium numerical simulation of low-power nitrogen-hydrogen arc heating engine is carried out. The model includes the total energy equation and the electron energy equation, and the plasma components include seven components: molecule, atom, ion and electron. The chemical kinetic models used include important kinetic processes, such as nitrogen and hydrogen decomposition, ionization, and so on. The physical properties of the gas are calculated in real time according to the local composition and temperature. The gas temperature and fraction density distribution in the engine are obtained by calculation. The results show that the plasma near the engine axis is close to thermodynamic equilibrium. However, the plasma in the arc attachment region of the anode wall of the engine deviates significantly from the thermodynamic equilibrium, and the calculated component distribution indicates that there is an inverse mixing process in the arc heating engine. That is to say, the distribution of each component in the engine is obviously different from that of the inlet concentration. The hydrogen component decreases first and then increases along the radial direction from the center of the engine to the anode wall, while the concentration distribution trend of the nitrogen component is opposite to that of the hydrogen component. Further analysis shows that the diffusion of each component in the engine is mainly driven by the concentration gradient caused by the gas dissociation and ionization process.
【作者单位】：北京控制工程研究所;哈尔滨工业大学;北京航空航天大学宇航学院;
【基金】：国家自然科学基金(11575019,11275021) 民用航天项目(混合模式推进系统优化技术)
【分类号】：V430

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