热力学非平衡分子辐射中的重粒子影响

Impact of heavy particles in radiation from thermally nonequilibrium molecules

在高超声速再入流场中,气体处于热力学非平衡状态。在这一状态下,气体的辐射根据分子电子态的激发情况展现出与平衡态不同的光谱。分子的电子态激发主要通过碰撞完成。电子的质量远小于分子,当分子在与电子碰撞时,能量传递的效率将高于与重粒子的碰撞。在这种情况下,重粒子对分子的电子态激发的影响往往被忽略。文中计算了氮气分子与不同粒子碰撞的电子态激发速率,并计算了在热力学非平衡情况下分子电子态的分布。通过分析氮气分子与不同粒子碰撞的电子态激发速率随温度的变换特性,比较了与不同粒子碰撞的分子电子态激发效果。最终分析了在典型的流场环境下,重粒子对分子电子态分布的影响,以及对最终氮气第一正组的辐射光谱的影响。

In the reentry flow fields of hypersonic, the gas is thermally nonequilibrium. In nonequilibrium condition, the spectrum based on excitation of electronic states is different from that in equilibrium condition. Molecule is mainly excited by collision. As the mass of electron is greater than molecule, the efficiency of energy transfer by collision with electron is higher than colliding with heavy particles. In this case, the effect of heavy particles on excitation of molecular is always ignored. The electronic excitation rate of N2 collision by different particles was calculated, and the distribution of electronic states of molecular in thermally nonequilibrium was calculated too. By analyzing the electronic excitation rate of N2 collision by different particles with the temperature change, the excitation effects of these particles was compared. In classic flow field, the effect of heavy particles was described in this paper. Besides, the effect of heavy particles on N2 first positive spectrum was also shown.