二次燃烧对燃气弹射内弹道影响三维数值研究

Three-dimensional Numerical Simulation of Secondary Combustion Influence on Gas-ejection Interior Ballistics

为了进一步研究二次燃烧对燃气弹射内弹道的影响,采用三维非稳态雷诺平均Navier-Stokes方程和重整化群湍流模型对燃气弹射过程进行数值研究,运用动态分层动网格技术模拟尾罩的运动。与实验结果对比表明,二次燃烧工况获得的内弹道参数更接近实验值。数值研究结果进一步表明:多组分工况获得的燃气与空气接触面光滑,而二次燃烧工况接触面呈现褶皱现象;初容室内氧气质量分数的变化规律表明,二次燃烧现象发生在燃气发生器工作后的0.2 s内。受初容室内二次燃烧影响,弹射加速度呈现初期时二次燃烧大于多组分工况,后期多组分工况大于二次燃烧工况现象;二次燃烧现象提前了飞行器的出筒时间,减小了飞行器的出筒速度。

To further study the influence of secondary combustion on the interior ballistics,the three-dimensional unsteady Reynolds-averaged Navier-Stokes equations and renormalization group turbulent model were applied to numerically study the gas-ejection process.The tailor motion was simulated by dynamic mesh method.The simulation results were compared with the experimental results.The result shows that the parameters of secondary combustion interior ballistics are more similar with the experimental values.The numerical simulation results show that the contact surface between gas and air is smooth in multicomponent case,however,the contact surface is plicate in secondary combustion case.The oxygen mass fraction in the initial chamber plots indicates that the secondary combustion phenomenon occurs within 0.2 s after the gas generation working.Influenced by the secondary combustion,the acceleration of secondary combustion case is higher than multicomponent case at the start time,but lower at the following time.The secondary-combustion phenomenon advances the out-tube-time of aircraft and decreases the out-tube-velocity of aircraft.