Research On Trajectory And Test Environment Of Rotating Gun Projectile

In order to provide a reference for the design of the fuze of a rotation number counting shrapnel for air burst in fixed distance used in a certain type of tank, attenuation law of angular spin rate of the tank gun cartridge in the exterior ballistics was studied by aerodynamics theory. The influences of Mach number, spin rate and attack angle were studied with Fluent numerical simulation. Pole damping moment coefficients were fitted nonlinearity and substituted into differential equations of angular spin rate to calculate the rotational speed and revolution. The results were compared with the theoretical calculation results and verified by range test. Effect of high-temperature propellant gas on the base fuze of projectile was studied with unsteady heat conduction calculation method and thermal-structural couple analysis method. The impact characteristic of hammer testing machine was analyzed by theory and ANSYS/LS-DYNA numerical simulation.Attenuation law of angular spin rate of spinning projectile in the exterior ballistics is studied by establishing mathematical model of attenuation law of angular spin rate of spinning projectile in the exterior ballistics and compiling the general program that calculates the roll damping of spinning projectile with MATLAB. The theoretical analysis and the numerical results obtained by the 4 empirical formulas are basically consistent. The results are credible and can be used in the analysis and design of fuze.Fluent numerical simulation results show that the larger the projectile velocity and attack angle is, the smaller the damping moment coefficient is, when the projectile velocity is greater than 1.5 Ma. The higher the projectile speed is, the greater the damping moment coefficient is. The attack angle is one of the main reasons that lead to the change of the pole damping torque coefficient of the projectile. Rotating band groove can not be ignored in the analysis of exterior ballistics. According to the simulation results of the pole damping torque coefficient, the exterior ballistic elements were calculated. Comparing with the results of mathematical model of attenuation law of angular spin rate, the traditional model and the range test data, the mathematical model of attenuation law of angular spin rate is more accurate.The results of unsteady heat conduction calculation method and thermal-structural couple analysis method show that the temperature on the surface of base fuze is far from the melting point of the material. The thermal disturbance propagation in the fuze body is very shallow. There is little influence on the strength of the fuse body and the internal temperature of the fuze is maintained at normal temperature.The results of theoretical analysis and ANS YS/LS-DYNA numerical simulation show that the greater the number of working teeth of a hammer testing machine is, the greater impact load and narrower pulse duration the test product have. Under the same number of working teeth, the smaller the total quality of test products and auxiliary tools, the greater speed and impact load the test product have. When the number of working teeth is not more than 23 and the total quality of test products and auxiliary tools is not more than 421 g, the maximum impact load of hammer testing machine is about 30000 g, the pulse duration is about 110 μs～150 μs.