Computational Study of Safe Separation of Sabot from Penetrator in APFSDS

The paper addresses the computational fluid dynamics solution for safe separation of sabot from the penetrator in armour piercing fin stabilised discarding sabot. The design and functional characteristics of sabot are modelled to achieve a safe trajectory. Driving bands are important components of APFSDS which adds the sabot together to efficiently transfer the gas forces on penetrator. Sabot, penetrator, fins, and driving bands are modelled separately which further assembled together using solid works CAD software. All tri-element is used to generate the unstructured surface mesh of the model using ICEM software. The aerodynamic coefficients of lift, drag, and moment acting on the penetrator and sabot discard process are evaluated by using in house developed finite volume-based implicit solver. The discarding process of sabot generates shocks at supersonic speed which can affect the trajectory of the penetrator during flight. The timely breaking of bands, after muzzle exit, the APFSDS is an important phenomenon to simulate and govern safe separation of sabots. Based on finite element method software, the breaking of bands was simulated to find the stress and deformation under pressure force exerted on sabot cups. The pressure exerted on sabot cups and separation of sabot due to aerodynamic forces were simulated using in house developed finite volume-based implicit CFD solver. The Cl, Cd, and pitch moment are plotted against the angle of sabot with penetrator which clearly indicates the uniform separation of the sabot.