Chemical-kinetic problems of future NASA missions
Chemical-kinetic problems of future NASA missions
复制标题
美国宇航局未来任务的化学动力学问题
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
G. Candler
中科院分区：
文献类型：
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作者：
Chul Park;J. Howe;R. Jaffe;G. Candler
本文研究了以超高速度进入地球和火星大气层的飞行器周围激波层的热化学非平衡，导出了反应速率系数，这些系数再现了激波管中获得的实验数据。给出了激波管流动和钝头体激波层流动的热力学性质和辐射强度。结果表明，烧蚀热屏上的烧蚀产物粘性层可能处于化学非平衡状态。在大气制动轨道上，在预期辐射峰值点处，地球进入飞行的非平衡区厚度在~ 2cm之间，火星进入飞行的非平衡区厚度在8 ~ 23 cm之间。对于进入地球的情况下，非平衡现象减少辐射加热率，而发生相反的情况下，火星。辐射传热率是显着的火星进入条件下，进入速度等于或大于7公里/秒。
Thermochemical nonequilibrium in the shock layer surrounding vehicles entering the atmospheres of earth and Mars at superescape velocities is studied, deriving reaction rate coefficients that reproduce experimental data obtained in shock tubes. Thermodynamic properties and emitted radiation intensities are obtained for shock tube flow and flow in a shock layer over a blunt body. The results indicate that the viscous layer of the ablation product over an ablating heat shield is likely to be in chemical nonequilbrium. For earth entry flight, the thickness of the nonequilbrium region is between and 2 cm at the expected peak radiation point in the aerobraking trajectory, For Martian entry flight it is between 8 and 23 cm. For the earth entry case, nonequilibrium phenomena reduce radiative heating rate, while the opposite occurs for the Martian case. The radiative heat transfer rates are significant for the Mars entry conditions at entry velocities equal to or greater than 7 km/s.