化学反应动力学对超声速燃烧的影响

Numerical study on supersonic combustion using different chemical reaction dynamics

关键词:  超音速燃烧  化学反应动力学  温度  反应速率

Key words:  Supersonic combustion  Chemical reaction dynamics  Temperature  Reaction rate

摘要:

非平衡化学反应是超声速燃烧中非常重要的过程,其反应动力学模拟直接影响其内部温度分布。针对某支板氢燃料超声速燃烧室,分别采用了单步化学反应动力学、7组分8步反应和9组分19步反应动力学模型,对比了燃烧反应速率、内部温度场和速度场的分布。结果表明,采用详细化学反应动力学,燃烧热释放缓慢,在流场中下游自由基参与反应,其温度场与试验值吻合更好。

Abstract:

The simulation of non-equilibrium chemical reactions influences the internal temperature profile for supersonic combustion greatly.The numerical analysis of supersonic combustion with hydrogen was carried out using different chemical reaction model,which include one-step,eight-step with 7 species and 19-step with 9-species chemical reactions.By the comparison about reaction rate,temperature profile and velocity distributions,the results show that the agreement between the numerical and experimental temperature is better when using detailed chemical reaction dynamics.The main reason is that the appearance of free radicals makes the reactions more actively in the downstream of flow field so that the release process of combustion heat becomes longer.