燃气二次喷射推力矢量控制系统启动过程非定常效应研究

Unsteady characteristic research of startup process of secondary hot gas injection thrust vector control system

采用数值模拟方法对燃气二次喷射推力矢量控制系统启动过程中非定常效应进行了研究。给出了详细的喷流瞬态干扰流场结构,以及喷流瞬态干扰区随时间改变的流场细节特性,分析了流动参数和发动机内弹道性能的动态变化过程。研究表明,主/次流干扰流场内流动参数的分布及变化呈现复杂的多样性,启动过程中所呈现出的动态特性与系统稳定工作时有着明显的差异,侧向控制力、燃烧室平衡压强和发动机推力均有显著变化。在飞行器设计中,必须从安全控制的角度出发,考虑这一非定常效应的影响。

CFD analysis technique is applied to study the unsteady characteristic of startup process of secondary hot gas injection thrust vector control system. It detailedly discussed transient jet-interaction flowfield structure and detailed characteristic of flowfield changed with the time in transient jet-interaction section. It also analyzed the dynamic process of flow parameters and interior ballistic performance of the motor. The results indicate that the distribution and change of flow parameters in the main/second flow interaction section present complex diversity. During the process of startup, visible difference on dynamic performance is displayed, compared with the situation of steady operation. Especially lateral control force, chamber pressure and motor thrust are changed remarkably. So the effect of unsteady characteristic should be paid attention in aerocraft design.