Study On The Ballistic Characteristics Of Hollow Training Missiles For Simulated Overspeed Shelling And Armor-piercing Projectiles

In order to provide technical basis for the development of hollow projectiles,multiple structures hollow projectiles with typical design scheme was numerically simulated by Fluent software.And the aerodynamic parameters under different Mach number and attack angle were obtained.On the basis of the projectile exterior trajectory model and optimization design theory,a model of aerodynamic-external ballistic optimization design was established.To optimize preliminary design of the hollow training projectile which was simulated supersonic APDS.The Monte-Carlo method and trajectory equation of projectiles were applied,and the simulation prediction model of vertical target dispersion of projectiles was established.The ballistic match test were used to optimized hollow training projectile and supersonic APDS.The hollow projectiles impacting the soil medium was numerically simulated by LS-DYNA software.Simplified model hollow projectiles with typical design scheme were numerically simulated by Fluent software.The relationship between drag coefficient and Mach number were obtained.On this basis,trajectory centroid group equations group of motion were solved using Matlab software,and the firing data of trajectory vertex and impact point was obtained.Compared the simulation results of drag coefficient and ballistic firing data with theoretical formula calculated.The results of simplified model hollow projectiles between simulation and theoretical calculations has a little difference when incoming flow Mach number between 2.0 and 4.4.Leading edge thickness of hollow projectile has little effect on the drag coefficient in the confidence interval,but rotating band structure has a greater impact on the drag coefficient.Three kinds of hollow projectiles with typical structure was numerically by Fluent software.The drag coefficient,lift coefficient,pitch moment coefficient and pressure center position under different angle of attack and different mach number was got.The relationship of the drag coefficient,lift coefficient,pitch moment coefficient and the position of the pressure center with attack angle were fitted by Matlab software.The drag coefficient and lift coefficient of the hollow projectiles were increasing with the increase of the angle of attack.The relationship between the drag coefficient of hybrid conical hollow projectiles and outer conical hollow projectiles and attack angle can be described by the quadratic function without the first term.And cubic function formula can be used to describe the relationship between the lift coefficient,pitching moment coefficient and attack angle.Under the same Mach number,the pressure center position moved toward the bottom of the projectiles with the increase of the attack angle.As well as,under the same attack angle,the pressure center position also moved toward the bottom of the projectiles with the increase of Mach number.The hollow projectile was optimized through the model of aerodynamic-external ballistic optimization design.Compared external ballistic parameters of the optimized hollow training projectile with supersonic APDS.And the internal ballistic design of the optimized hollow training projectile was carried out.The external ballistic parameters were closed between the optimized hollow training projectile and supersonic APDS.Such as the time difference between them is only 0.0047 s when the range is 2500 m.Firing simulations of 1000 m,2000 m,3000 m vertical targets were carried out on the optimized hollow training projectile and supersonic APDS,and each range under the simulated shooting 3 groups,each group shot 5 rounds.The ballistic match test method in the GJB 349.17 "Conventional Weapon Test Methood" and the ballistic match test grouping test method were used to test the ballistic match of the results obtained by the simulation of the two projectiles,both can be obtained to meet the ballistic match of the test results.The hollow projectiles with different terminal velocity,different terminal angle and different rotation speed impacting soil medium was numerically simulated by LS-DYNA software.And the trajectory of hollow projectiles in soil were obtained.Under the same impact angle,the higher the terminal velocity,the greater the mass loss of the hollow projectiles in the penetration process,and the deeper the penetration depth of the soil.With the same impact terminal velocity,the greater of attack angle,the deeper the penetration depth of the hollow projectiles,as well as,the smaller the angle,the easier jump bomb.Under the same impact angle,terminal velocity,the higher of rotation speed,the deeper of the penetration of hollow shells projectiles soil.