大气呼吸模式激光推进的机理分析及数值模拟  

Mechanism analysis and numerical simulation of air-breathing model for laser propulsion

作　　者：龚平[1] 唐志平[1] 

机构地区：[1]中国科学技术大学力学和机械工程系中国科学院材料力学行为和设计重点实验室,安徽合肥230026

出　　处：《爆炸与冲击》2003年第6期501-508,共8页Explosion and Shock Waves

摘　　要：就大气呼吸模式的推进机理作了较为系统的分析和研究,导出了考虑反射面几何约束的冲量及冲量耦合系数的近似解析表达式。在数值模拟方面,采用前期点爆炸自模拟解和后期高分辨率PPM格式相结合的新方法,计算了固定的抛物面反射镜聚焦入射平行激光击穿空气形成的高温等离子体流场及其对反射面产生的推动作用。结果表明,推进效应(飞行器获得的推力、总冲量、冲量耦合系数等)与反射面的几何参数和入射激光强度密切相关。83J的激光单脉冲能量算例得到的冲量耦合系数为246μN·s/J,略高于同种工况下W.O.Schall等实验得到的耦合系数。The mechanism of air-breathing mode has been analyzed systematically and the analytic formulas for the momentum coupling coefficients based on point explosion theory have been derived and improved by considering the restraint of the reflector. In the numerical simulation, a new method that combine the self-similarity solution for point-explosion at the first stage and the high resolution PPM grids at the second stage, has been applied to calculate the high-temperature plasma flow field generated by the focused laser beam. The simulated results show that the efficiency of laser propulsion, such as thrust, total impulse, momentum coupling coefficient, are strongly related to the geometry of the reflector and the power of the laser beam. A calculated example for a single laser pulse of 83 J gives the momentum coupling coefficient of 246 μN&middots/J, which is about 10.3% higher than the experimental result of W. O. Schall et al in Germany.

关 键 词：大气呼吸模式 激光推进 数值模拟 爆炸力学 点爆炸 冲量耦合系数 PPM格式 高温等离子体流场 

分 类 号：O381[理学—流体力学] O432.12[理学—力学]