| Taking a new grenade launcher as the research object,aiming at the problem of excessive recoil during high initial velocity launch,the technology using a partition to control when the rear chamber and the nozzle are connected with a nozzle and two chambers is adopted in this paper.The two-phase flow model and numerical simulation of weapon launching process are carried out by using the two-phase flow interior ballistic theory.The dynamic simulation of weapon virtual prototype model is carried out by using multi-body dynamics theory.Particle swarm optimization algorithm and finite element method are used to optimize the interior trajectory and weapon structure.It provides a theoretical basis for the design of a new high muzzle velocity grenade launcher using the recoil reduction technology.(1)The advantages and disadvantages of reducing recoil technology of jet gas with laval nozzles and the recoil reduction technologies using propellant gas,two rarefaction wave recoil reduction methods with side to rear jet controlled by piston movement or gas conduction are analyzed.On this basis,a technology using a partition to control when the rear chamber and the nozzle are connected with a nozzle and two chambers is proposed.The recoil reduction technology creatively transforms a single chamber of an ordinary projectile into two chambers(front chamber and rear chamber),leads out the Laval nozzle on the side of the barrel,and controls the connection time between the rear chamber and the nozzle by setting the limit pressure of the rear spray diaphragm.The recoil reduction technology independently provides gunpowder and gas energy for weapon recoil reduction through the rear chamber,which can greatly reduce the recoil force of the weapon and improve the mobility and safety of the weapon.(2)Based on the theory of two-phase flow interior ballistics,the mathematical model and numerical simulation of the launch process of recoil weapon using a partition to control when the rear chamber and the nozzle are connected with a nozzle and two chambers are carried out.According to the characteristics of weapon structure and launching process,a two-phase flow interior ballistic model is established.According to the mathematical properties of the model,appropriate numerical algorithms and boundary conditions are selected for solution.Through the analysis of flow field parameters between different calculation domains and the comparison with the internal ballistic performance of ordinary weapons,the recoil reduction mechanism is revealed.The results show that the recoil impulse of recoil reduction weapon decreases from-114.798N·s to-28.47N·s,and the recoil reduction efficiency is 75.199%.The effects of structural parameters such as the limit pressure of the rear spray diaphragm,the charge amount in the rear chamber,the size of the guide hole in the barrel and the charge parameters on the internal ballistic performance are analyzed.The interior ballistic program in the form of graphical user interface is compiled to enhance the operability of the program.(3)Based on the internal ballistic program and the analysis of the influencing factors of the internal ballistic of the recoil weapon using a partition to control when the rear chamber and the nozzle are connected with a nozzle and two chambers,in order to further reduce the recoil impulse of the grenade launcher,the particle swarm optimization algorithm is used to optimize the structure of the weapon.The optimization results show that the recoil reduction impulse of the optimized scheme is reduced by 5.268N·s,the recoil reduction efficiency is79.789%,the pressure difference between the front and rear chambers is reduced from91.984 MPa to 82.457 MPa,and the safety performance of the weapon is also improved.Based on the optimized recoil reduction scheme,the three-dimensional solid model of the projectile is established,the strength of the front chamber shell is checked,and the structure of the shell is optimized according to the results,so as to ensure the safety of the launch process of the recoil reduction weapon.(4)The three-dimensional solid model and virtual prototype model of grenade launcher based on the recoil device using a partition to control when the rear chamber and the nozzle are connected with a nozzle and two chambers are established for dynamic simulation.The comprehensive influence of recoil reduction device,buffer and brake on recoil force is analyzed.The results show that when the three parameters are reasonably matched,the maximum recoil force is reduced by 80.022% compared with the traditional pneumatic automata.In order to verify the recoil reduction effect of weapon,a double chamber ammunition and weapon prototype were developed and tested. |
