基于压力损失的轻气炮内弹道建模及仿真分析

Interior Ballistic Modeling and Simulation Analysis of a Light Gas Gun Based on Pressure Loss

针对轻气炮发射过程中弹前空气阻力对弹丸速度影响的考虑,引入压力损失因素并联立弹丸运动方程、理想气体状态方程等,构建基于压力损失的轻气炮内弹道数学模型(改进方程)。分析了轻气炮中关键参数与弹丸速度的影响关系,计算了改进方程和经典方程在同等参数匹配下弹丸速度的差异,进一步对弹丸发射全过程进行流体仿真。结果表明:设计轻气炮的弹丸速度低于900 m/s时,不考虑弹前空气阻力的影响对理论计算结果造成的误差小于8 m/s;流体仿真结果与数值分析结果基本吻合,证明了改进方程的正确性,研究结果对于指导轻气炮的工程设计和提高理论计算精度有一定的参考价值。

In view of the influence of resistance exerted by the air before the projectile on its velocity during the launch process of a light gas gun, the pressure loss factor is introduced in parallel with the projectile motion equation and the ideal gas state equation, etc., and the mathematical model of the light gas gun interior ballistics based on pressure loss(improved equation) is built. The relationship between key parameters of the light gas gun and projectile velocity is analyzed. And the difference of projectile velocity between the improved equation and the classical equation under the same parameter matching is computed. This is followed by a fluid simulation of the whole launch process of the projectile. The results show that when projectile velocity of the designed light gas gun is lower than 900 m/s, the error of the theoretical calculation result without considering the influence of the air resistance before the projectileis less than 8 m/s. The fluid simulation results are in good agreement with the nume-rical analysis results, which proves the correctness of the improved equation. The research results can serve as a reference for guiding the engineering design of light gas guns and improving the accuracy of theoretical calculation.