Abstract: The investigation on the dynamics process of launch of ammunition under different conditions is important for improving its performance during design and contributes to adapt the complex variable modern battlefield for the ammunition. For the purpose of improving the firing accuracy and flight stability of an armour-piercing fin-stabilized discarding sabot, the sabot dynamic discarding behavior after the projectile being ejected from the muzzle at non-zero angles of attack and sideslip is simulated by coupling the computational fluid dynamics and the six degree of freedom exterior ballistic code through the unstructured dynamic mesh technique and user defined function. The flow field characteristics and the trajectory parameters of all sabots are obtained. In addition, the aerodynamic coefficients of projectile are also obtained. The numerical results show that the asymmetric flow field of the sabots can be observed under the influence of the asymmetric inflow. This will lead to the nonuniform distribution of pressure on the sabot surfaces. The different trajectories of three sabots appear due to the unsynchronized and asymmetrical discarding of sabot. The increased aerodynamic interference between projectile and sabot reduces the firing accuracy and flight stability of projectile.

Key words: ordnance science and technology, armour-piercing fin-stabilized discarding sabot, unsynchronized and asymmetrical discarding, aerodynamic coefficient, unstructured dynamic mesh technique, six degree of freedom motion, shock wave