Research On The Technology Of Multi - Functional Flare

In order to provide a reference for a large caliber smoothbore gun multipurpose projectile’s base percussion fuze design, the spin rate of a fin guiding spin projectile was calculated by the method of air dynamics theory, and the range spin rate test was conducted. The influence of flow and spin rate to the roll moment characteristics were studied with FLUENT numerical simulation. The set-forward overload of base fuze during projectile’s penetration of C35 plain conceret target was studied with ANSYS/LS-DYNA numerical simulation. And the influence of target thickness, impact speed, impact angle to the set-forward overload was analyzed.The theoretical calculation and anlysis of spin rate indicates that the fin guiding spin projectile’s spin rate can reach maximum quickly after the muzzle. The maximum spin rate is influented by velocity, compared with the classical design theory of balancing spin rate. The fin bevel angle has a signification influence on spin rate of fin turning spin projectile. Comparing the theoretical calculation results and range test, the relative error is less than 15%.Fluent numerical simulation results show that the polar damping moment coefficient decreases with increasing of flow velocity and angle of attack, linearly increase with incre-aseing of spin rate of projectile. The influence of flow velocity and angle of attack to fin guiding spin moment coefficient varies with flow velocity range. When flow velocity is subsonic, it decreases with increasing of flow velocity and angle of attack. When flow velocity is transonic, it decreases with increasing of angle of attack, and increases significantly with increasing of flow velocity. When flow velocity is supersonic, it decreases with increasing of flow velocity, and increases with increasing of angle of attack.ANSYS/LS-DYNA numerical simulation results show that the set-forward acceleration of base fuze increases with increasing of target thickness during penetration of conceret target. But when the thickness reaches a certain value, no longer increases the forward acceleration. The set-forward acceleration increases with increasing of impact velocity, and it is influented by impact angle, but the variation is not obvious. Ricochet will occur with the increase of impact angle. The maximum set-forward acceleration range is 1.53×104g～3.14×104g for a 125 mm smoothbore multipurpose projectile during its effective range. According to the simulation data, the empirical formula of projectile’s maximum acceleration during penetration in limited thick C35 plain concrete target is obtained.