Simulation of aerothermodynamics model on ballistic safety of fusible alloy fuze

In order to ensure the ballistic safety of fusible alloy fuze at reliable delay arming, melting point of fusible alloy needs to be calculated based on projectile velocity at safe time and distance. Taking shrapnel KZVD fuze of Switzerland oerlikon 2ZLa/353 35 mm double barrel self-propelled antiaircraft artillery as an example, based on the aerodynamics heating theory, the calculation of theory model and simulation of projectile head stagnation point temperature were done in initial stage of sim-plified exterior ballistic from engineering viewpoint when the initial projectile velocity was 1 175 m/s and the error was ±15 m/s. The melting point of fusible alloy in the safe distance was obtained by analyzing the temperature of projectile head stagnation point at corresponding projectile velocity. The simulated results indicate that the melting point of fusible alloy de-rived by theoretical calculation is identical with the result of simulation at the velocity range of 1 160 to 1 190 m/s. So the aero- thermodynamics model can be applied to design the fusible alloy fuze of corresponding melting point based on the requirement of safe distance. This method can be taken as the reference in studying the thermodynamic question of projectile flying at high speed.

Dynamic transfer model and applications of a penetrating projectile‐fuze multibody system

In modern warfare,fortifications are being placed deeper underground and with increased mechanical strength,placing higher demands on the target speed of the penetrating munitions that attack them.In such practical scenarios,penetrating fuze inevitably experience extreme mechanical loads with long pulse durations and high shock strengths.Experimental results indicate that their shock accelerations can even exceed those of the projectile by several times.However,due to the unclear understanding of the dynamic transfer mechanism of the penetrating fuze system under such extreme mechanical conditions,there is still a lack of effective methods to accurately estimate and design protection against the impact loads on the penetrating fuze.This paper focuses on the dynamic response of penetrating munitions and fuzes under high impact,establishing a nonlinear dynamic transfer model for penetrating fuze systems,which can calculate the sensor overload signal of the fuze location.The results show that the relative error between the peak acceleration obtained by the proposed multibody dynamic transfer model and that obtained by experimental tests is only 15.7%,which is much lower than the 26.4%error between finite element simulations and experimental tests.The computational burden of the proposed method mainly lies in the parameter calibration process,which needs to be performed only once for a specific projectile‐fuze system.Once calibrated,the model can rapidly conduct parameter scanning simulations for the projectile mass,target plate strength,and impact velocity with an extremely low computational cost to obtain the response characteristics of the projectile‐fuze system under various operating conditions.This greatly facilitates the practical engineering design of penetrating ammunition fuze.