Optimization of Mixed Charge Comprising Seven‐Perforated and Sudden‐Surface‐Increase Capsule Propellants

ABSTRACT Delayed ignition can significantly enhance the combustion progressivity of propellants. This study proposes a novel capsule‐shaped propellant designed to achieve delayed ignition. It is composed of a thin‐walled tubular propellant‐prepared shell and internally freely piled spherical propellants. To further optimize the combustion performance, the capsule propellant is blended with 7‐perforated propellant. The combustion performance of the mixed charge with the mixing and the web thickness ratio as variables was theoretically calculated and experimentally verified. Optimal performance is achieved when the capsule and 7‐perforated propellants are consumed at the same time. The computational results demonstrate that a 40% mass fraction of capsule propellant achieves two equal peak pressure values. Under this condition, the projectile's muzzle velocity increases by 6.1% relative to the pure 7‐perforated propellant and by 1.8% compared to the 19‐perforated rosette propellant. The combustion performance of the mixed charge was evaluated using a closed vessel test. The combustion progressivity of the mixed charge was analyzed using the actual form function method. The results show that when both are completely burned simultaneously, a capsule proportion of 20% to 40% can achieve a good combustion progressivity.