Study On Unbalanced Impulse Of Rocket Launcher With Rear Spray Recovery Nozzle

This paper designs a nozzle for a rocket weapon launcher,which is used to recover the plug cover ejecting from the back of the rocket launcher.Firstly,the feasibility of the nozzle recovery plug was verified by experimental research,and the gas jet flow field of the rocket launcher with rear spray recovery nozzle was imaginatively explored,and the method of reducing the impact force of the nozzle was put forward.Secondly,the distribution of the gas jet flow field of the rocket launcher with rear spray recovery nozzle recovery nozzle and the influence of different nozzle models on the nozzle imbalance impulse are analyzed by numerical simulation.Finally,the best design scheme that can effectively recover the plug cap is obtained,which is of great significance to optimize the nozzle structure design and improve the security and stability of rocket launcher.The main research work of this paper is as follows:(1)The feasibility of nozzle recovery plug cap was verified by launching test of rocket launcher.A high speed camera was used to record the gas jet flow field of the rocket launcher with rear ejection recovery nozzle,and the results were analyzed.The idea of optimizing nozzle structure and reducing the impact force of jet on nozzle was put forward.(2)The numerical model of rocket launcher’s internal ballistic process was established based on classical internal ballistic theory,and the fourth-order Runge-Kutta method was used to complete the numerical simulation calculation and compared with the experimental results,providing the gas pressure inlet conditions and the rocket movement law for the numerical simulation of the gas jet flow field of rocket launcher with rear spray recovery nozzle.(3)Establish with spray content after the recovery nozzle rocket gas jet flow field of the mathematical model,which contains the numerical calculation method,choice of control equations,turbulence model,meshing,the use of fluid simulation software for two-dimensional asymmetric gas jet flow field calculation,the gas jet nozzle blocking cover,movement and interaction characteristics are simulated.It is found that the plug has little effect on the unbalanced impulse of the nozzle,and the impact force and the unbalanced impulse of the nozzle are obviously oscillating.(4)Numerical simulation of gas jet flow field of rocket launcher with different parameters was carried out.By changing three parameters of nozzle recovery body length,inner diameter of nozzle recovery and nozzle expansion Angle,the change law of impact force and unbalanced impulse of nozzle was studied.Through comparative analysis,the optimal nozzle structure design scheme of nozzle recovery plug cap was obtained.