Abstract: The non-equilibrium and frozen flows of scramjet nozzle were numerically simulated to study the effects of radical recombination on the nozzle performance, based on 13-species and 33-step H₂/Air finite-rate chemistry reaction mechanism. The numerical results show that the recombination occurs during the expansion in scramjet nozzle and that is beneficial to the nozzle performance. With the increase in the flight Mach, the effects of radical recombination on the nozzle performance are more significant. The nozzle performance has improved nearly 2% because of the recombination when the flight Mach is 8.0, and there is nearly no effect to neglect the NO_2and H₂O_{2compositions} on the results of nozzle performance computation. 

Key words: Scramjet;Nozzle; Non-equilibrium chemical reaction flow; Radical;Performance calculation

摘要： 采用13组分33步反应的H₂/Air化学动力学模型,对超燃冲压发动机尾喷管化学非平衡流动和冻结流动进行数值模拟。计算表明,离解组分的复合现象存在于超燃冲压发动机尾喷管内流动中,并对尾喷管性能产生影响。随飞行马赫数的增加,离解组分复合现象更显著,对尾喷管性能产生的影响也越大。在飞行马赫数为8.0的计算工况下,化学非平衡流动模型计算所得尾喷管性能与冻结流动模型相比高出约2%,该条件下忽略NO₂,H₂O₂等组分以简化化学反应机理,对尾喷管性能计算结果的影响甚微。 

关键词: 超燃冲压发动机;喷管;化学非平衡流动;离解;性能计算 