喷管喉部直径对无后坐力枪内弹道影响分析OA

To enhance the dynamic stability during recoilless firing,the study investigates the thrust dynamics of Laval nozzle under conditions of induced ignition,deflagration and high chamber pressure.A numerical calculation model for internal ballistics of recoilless firing under heavy loading conditions was established.Through numerical simulations,the influence of structural parameters on Laval nozzle thrust was analyzed,revealing the thrust variation patterns with throat diameter.An experimental recoilless firing system was constructed to study the exhaust flow field and thrust changes during the firing process.The results indicate that under the fluid-structure coupling effect of pyropropellant gas and solid particles,the Laval nozzle can provide an impulse of over 24 N·s within approximately 4 ms.The Laval nozzle thrust begins to act when the tail membrane ruptures the nozzle during firing,allowing gas to be expelled rearward.Subsequently,as the chamber remains open and the propellant has not yet burned extensively,the released pyropropellant gas is limited,resulting in a downward trend in chamber pressure.When the propellant inside the chamber begins to burn vigorously,large amounts of pyropropellant gas are generated,causing the chamber pressure to rise rapidly and reach the maximum.At this point,significant gas is expelled from the Laval nozzle,leading to a rapid increase in thrust.As the propellant burns completely,the chamber pressure decreases,and the Laval nozzle pressure gradually declines until the propellant is fully consumed.The Laval nozzle exhibits high thrust characteristics under pyropropellant deflagration and elevated chamber pressure conditions,capable of delivering substantial instantaneous impulse.