火箭发射燃气流二次燃烧数值研究

Numerical Research on Jet Secondary Combustion of Rocket Launch

为研究二次燃烧对火箭地下热发射排焰环境的影响,采用9组分11步反应的H_2-CO燃烧模型模拟火箭出井过程中发动机的燃气流与空气二次燃烧过程,运用域动分层动网格技术,对火箭运动区域进行更新,数值研究二次燃烧对井内流场温度、压力载荷以及火箭出井速度和时间的影响。数值结果表明,富燃燃气与空气混合发生二次燃烧,导致井内局部燃气流温度、压力升高,但在井底导流锥冲击区、排焰道转弯区以及箭体底部和箭体壁面部位温度、压力载荷分布受二次燃烧的影响较小,相对变化率均不大于8.33%;火箭出井速度和时间受二次燃烧的影响可以忽略。

To research the influence of the secondary combustion on the liquid rocket underground thermal launching environment, a H2/CO combustion model which consists of 9 components and 11 reactions is used for the secondary combustion simulation. At the same time, the zone moving and dynamic laying method is used to update the moving zone below the rocket base cover. Then, the numerical simulation is applied to study the influence of the secondary combustion on the flow field temperature, pressure and rocket internal trajectory in silo. The numerical results demonstrate that the secondary combustion could enhance the temperature and pressure at the iota1 region of silo. However, the temperature and pressure change is very little at the critical area of silo. Compared to the flow filed without secondary combustion, the change is not larger than 8.33%. Meanwhile, both the rocket velocity and the time when the rocket flies out of the silo have been little affected by the secondary combustion.