| The two-stage light gas gun is a barrel shooting device based on the expansion and work of compressed gas to launch projectiles.It can drive projectiles of different materials and shapes to more than 3km/s,and is widely used in research fields such as damage effect of kinetic energy weapons,geospace physics,spacecraft protection and material dynamics performance.It is the most common high-speed and ultra-high-speed loading equipment at home and abroad.The optimization of its interior ballistic characteristics and launch parameters is of great significance for the theoretical research and engineering practice of light gas gun.In order to further explore the driving ability of the two-stage light gas gun,this paper mainly focuses on the calculation program of the two-stage light gas gun internal ballistic parameters,the testing of internal ballistic parameters during launch and the optimization of internal ballistic launch parameters,and carries out the following work:(1)Establishment of interior ballistic model of two-stage light gas gun.In order to accurately describe the motion state of the piston,projectile and high-pressure gas of the two-stage light gas gun,based on the one-dimensional unsteady,non-viscous,compressible and variable section fluid mathematical model of computational fluid dynamics(CFD),the internal ballistic calculation program of the two-stage light gas gun was developed by itself,and the motion time history of the piston and projectile could be obtained.The experimental data published in the literature are used to verify the accuracy of the self-programmed calculation program,and the effect is good.(2)Internal ballistic parameter test of two-stage light gas gun.By attaching strain gauge to the outer surface of the barrel,the motion time history of the piston and projectile inside the barrel,the recoil force caused by the firing of the piston and the forward impulse force caused by the piston entering the cone were measured without damaging the barrel.A large range pressure sensor was installed by opening a hole in the high pressure cone section to test the time history of pressure change in the secondary high pressure chamber.By installing a displacement sensor outside the cone section,the forward thrust displacement of the cone section caused by the piston entering the cone is measured.A three-way laser projectile velocity test system is used to obtain the projectile velocity when the projectile flies out of the muzzle.The motion course of the high pressure cone section was captured directly by high speed photography.Through the multi-kind hardware fusion test method,the change process of the physical parameters of the bore of the key parts of the two-stage light gas gun during the launching process is basically mastered,which provides direct data support for the verification of the subsequent internal ballistic calculation program.(3)Research on optimization of launch parameters of two-stage light gas gun based on improved particle swarm optimization algorithm.The structural parameters of the inner bore of the two-stage light gas gun cannot be changed after completion,and there are still a series of adjustable firing parameters such as chamber gas injection pressure or powder charge,piston mass,pump tube gas injection pressure and type,diaphragm opening pressure,and projectile quality.In order to avoid damage to the gun body and obtain the highest firing velocity,an improved particle swarm optimization algorithm was used to optimize the firing parameters of the 155/65 mm two-stage light gas gun based on the mathematical model of interior trajectory and the actual range of firing parameters,taking the projectile exit velocity as the objective function.The results show that the improved particle swarm optimization algorithm has good convergence and search performance in the process of optimizing the firing parameters of two-stage light gas gun,and can quickly give the firing parameter combination corresponding to the highest firing velocity at the specified firing weight,and the optimal firing parameter combination at the specified firing weight and firing velocity.(4)The internal ballistic application platform of two-stage light gas gun was developed based on Python language and GUI technology.The platform can not only realize the numerical simulation graphics of the first light gas gun and the second light gas gun,but also provide a series of related functions of the theory and test of the second light gas gun,such as the management of experimental instruments,the management of experimental personnel,the management of experimental records,and the management of experimental data,which provides convenience for the researchers engaged in related research. |
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