Research On Multi-fragment High-speed Synchronous Launch And Dislocation Isochronous Separation Technology

In the actual anti-missile combat,it’ a effective method to produce a large number of dense scattered fragments by warhead;when dense flying fragments encounter with the missile warhead,the missile warhead and structure will be damaged by multiple fragments.At this time,the cumulative damage effect caused by multiple fragments damaging missile warhead and structure can’t be ignored.In order to simulate the cumulative damage effect on warhead under the condition of multiple fragments dislocation and asynchronous separation.This paper mainly studies the feasibility of high-speed synchronous launching of multiple fragments and dislocation of different time separation technology for a kind of pneumatic pop-up fragment separation device launched by ballistic gun.In this paper,the working principle of the pneumatic pop-up fragment separation device is analyzed.By using the two-stage air chamber on the sabot device,the double fragments are pushed out successively at different speeds,so as to simulate the different time separation effect when the double fragments damage the warhead;the dislocation separation effect between the two fragments depends on the dispersion caused by the whole launching and separation process.In order to analyze the high-speed synchronous launching process of double fragments,the pressure and velocity in the chamber of the sabot device are calculated by using the classical interior ballistics theory,and the micro equation model of the gas flow process in the chamber of the projectile in the interior ballistic stage is established by combining with the gas dynamics,and the variation process of the gas chamber pressure under different conditions is studied.In order to analyze the different time separation process of double fragments,the motion process of double fragments pushed out of the sabot device by high-pressure gas was modeled according to the isentropic adiabatic ideal gas equation,continuous equation and Newton’s second law.The changes of the double fragment motion process under different gas chamber volume ratio,different gas chamber pressure and different relative motion length were analyzed.The results show that the velocity difference between the two fragments can be changed by adjusting the volume ratio of the gas chamber,and then the effect of different time separation can be controlled.In addition,CFD software is used to simulate the process of fragment ejection of several typical sabot devices,and the results of simulation and theoretical calculation verify the reliability of the theoretical model.In order to analyze the degree of dislocation and separation of double fragments,the exterior ballistic differential equation group model of the sabot device and the double fragment is established by analyzing the stress process.Combined with the velocity and time of double fragments relative to the sabot,the distribution range of the displacement distance（centroid distance）of double fragments under different working conditions is calculated.The results show that the initial angle of attack acceleration of sabot device,the velocity and time of fragments relative to sabot device are the main factors affecting the distance between fragments.In this paper,according to the characteristics of dislocation and different time distribution of double fragments,through the design of the structure and gas path of the parts,a sabot device using the gas in the bore as the fragment separation power is obtained.The results show that the device can achieve the effect of dislocation and different time separation of double fragments,which has a certain reference value for the determination of relevant test scheme.