EFFECT OF NONEQUILIBRIUM BEHIND A STRONG SHOCK UPON RE-ENTRY AERODYNAMIC HEATING

高空空间运输系统进入大气层时，会产生很强的冲击波。这样的激波引起激波层气体的振动激发、解离和电离，由于密度非常低，流动将处于热和化学不平衡状态。虽然旋转温度与重粒子的平动温度迅速平衡，但振动温度和电子温度偏离了平动温度。因此，为了估算再入气动加热，需要揭示以下项目：(1)热非平衡效应：平动、振动和电子-平动能量模式之间的能量传递速率；(2)辐射效应：强激波后高温气体中的辐射强度；(3)壁面条件的影响：催化壁面对气动加热的影响，振动温度的壁面条件。在本研究中，对包括上述三种条件的非平衡流动进行了实验和数值研究。在钝体热化学非平衡流动的粘性激波层（VSL）数值分析中，采用三温度模型，揭示了非平衡激波层流动的结构。此外，还研究了壁面催化对气动加热的影响。利用活塞驱动激波管进行了实验，观察了高温气体在强激波后发射的辐射光谱。考虑Knudsen层边缘的振动能通量，通过理论分析推导出了壁的振动条件。

The atmospheric entry of space transportation systems at high altitudes generates a very strong shock wave. Such a shock wave causes vibrational excitation, dissociation and ionization of the shock layr gas, and the flow will be in thermal and chemical nonequilibrium due to very low density. Although rotational temperature is quickly equilibrated with translational temperature of heavy particle, vibrational temperature and electron temperature deviate from translational temperature. Therefore, in order to estimate re-entry aerodynamic heating, the following items should be revealed :(1) Effect of thermal nonequilibrium : energy transfer rates among translational, vibrational and electron-translational energy modes,(2) Radiative effect : Radiative intensity in high temperature gas behind a strong shock,(3) Effects of wall conditions : effect of catalytic wall on aerodynamic heating, wall condition for vibrational temperature.In the present investigations, nonequilibrium flows including the above three conditions are studied experimentally and numerically. In the numerical study of viscous shock layr (VSL) analysis of the thermochemical nonequilibrium flows over a blunt body, a three temperature model was treated and thereby the structure of nonequilibrium shock layr flows was revealed. In addition, the effect of wall catalysis on aerodynamic heating was investigated. Also, experiments were carried out using a piston-driven shock tube, and radiation spectrum emitting from the high-temperature gas behind a strong shock wave was observed. wall vibrational-condition has been deduced from theoretical analysis considering vibrational energy flux at the edge of Knudsen layr.