引信气动烧蚀的计算流体动力学仿真方法

Computational Fluid Dynamics Simulation Method of Fuze Aeroheating Ablation

传统的引信气动烧蚀研究主要采用理论分析结合试验的方式进行,存在计算复杂、速度慢、局限性大、计算结果误差较大以及对某些极端试验条件无法模拟等缺点。基于此,将计算流体动力学方法引入引信气动烧蚀仿真分析。该仿真方法定义了烧蚀准则和烧蚀时间步长,每用计算流体动力学方法计算一个时间段后,用烧蚀准则将烧蚀部分除去,然后按定义的烧蚀时间步长反复计算,直至完成全部模拟时间的计算。采用此方法对4 Ma速度下3s飞行时间火箭弹标准外形引信的气动加热烧蚀进行的仿真计算结果表明:计算出的引信外形随飞行时间的烧蚀情况与理论分析相吻合,证明了此方法的合理性。

Theoretical analysis combining experimental method are usually used in traditional research on fuze aeroheating ablation, but it has many disadvantages such as complex computation, low computation speed, narrow limitation, big error in computation result and it can＇t simulate some extreme experimental condition. Aiming at these problems, the CFD method was introduced to the analysis of fuze aeroheating ablation. Ablation rule and ablation time-step were defined by the method, and the ablated part were moved by the ablation rule after every computation of time slice, and the computation was repeated according to the ablation time step until the whole imitation time was completed. The simulation result of standard rocket fuze on 4 Mach flight velocity for 3 seconds showed that the ablation situation accorded with the theoretical analysis result, so the method was proved to be reasonable.