电离对高超声速热化学非平衡气动热环境的影响

Influence of ionization on hypersonic thermo-chemical non-equilibrium aerodynamic thermal environments

高超声速飞行,激波后高温气体会发生电离,飞行器气动热环境复杂。5组元(N_2,O_2,NO,O,N)、7组元(N_2,O_2,NO,O,N,NO+,e-)和11组元(N_2,O_2,NO,O,N,N+2,O+2,NO+,O+,N+,e-)热化学反应采用Gupta化学反应模型,分别数值研究电离作用对高超声速热化学非平衡气动热环境影响。本文分析了不同催化壁面条件下,高超声速热化学非平衡电离流场气动热环境特性。电离作用对激波离体距离和气动力载荷的影响很小。5组元热化学非平衡不考虑电离作用,流场温度和壁面热流密度偏大。11组元热化学平衡强电离流场温度最低; 7组元热化学非平衡弱电离流场NO+和e-生成量过低; 11组元热化学反应能对热化学非平衡电离流场气动力和热流密度载荷可靠预测。壁面催化作用会增大壁面热流密度,但它对高超声速热化学非平衡电离流场温度和气动力载荷的影响很小。

The high temperature gas after shock wave occurs to ionize in hypersonic flight,which makes the aerodynamic thermal environments to be complicated.The 5species (N2,O2,NO,O,N),7species(N2,O2,NO,O,N,NO+,e-)and 11species (N2,02,NO,O,N,N2+,O2+,NO+,O+,N+ ,e- ) thermo-chemical reactions of Gupta's chemical reaction model were taken to numerically study the influence of ionization on hypersonic thermo-chemical non-equilibrium aerodynamic thermal environments,respectively. The characteristics of hypersonic thermo-chemical non-equilibrium ionization flow field aerodynamic thermal environments in different catalytic wall conditions were also researched.The effect of ionization on the shock standoff distance and the aerodynamic force load is very small.The flow filed temperature and the wall heat flux calculated by 5species thermo-chemical non-equilibrium reactions are much bigger because the effect of ionization is not considered.The hypersonic strong ionization flow field temperature calculated by 11species thermo-chemical equilibrium reactions is the lowest.The amounts of NO+and e-in hypersonic weak ionization flow field calculated by 7species thermo-chemical non-equilibrium reactions are too small.The aerodynamic force and the wall heat flux loads in hypersonic thermo-chemical non-equilibrium ionization flow field can be effectively predicted by 11species thermo-chemical reactions.The wall heat flux increases when the effect of wall catalysis is considered.However,the temperature of hypersonic thermo-chemical non-equilibrium ionization flow field and the aerodynamic force load are less affected by the wall catalysis. =