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

空间运输系统在高空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、离解和电离，并且由于非常低的密度，流动将处于热和化学不平衡。虽然转动温度与重粒子的平动温度很快达到平衡，但振动温度和电子温度却偏离平动温度。因此，为了估计再入大气层的气动加热，应揭示下列项目：（1）热不平衡的影响：平动、振动和电子-平动能量模式之间的能量转移率，（2）辐射影响：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，壁面条件对振动温度的影响，本文对上述三种条件下的非平衡流动进行了实验和数值研究。在钝头体热化学非平衡流粘性激波层（VSL）分析的数值研究中，采用了三温模型，从而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，观测到了强激波后高温气体的辐射谱。考虑Knudsen层边界处的振动能流，从理论上推导了壁面振动条件。

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.