Abstract: In order to reduce the recoil force of automatic weapon system and keep the initial velocity of projectile unchanged, a time-delay nozzle flow recoil-reduction device is presented. The in-bore pressure drop is delayed by opening the gas port of the barrel in an appropriate time-delay, thus keeping the initial velocity of projectile unchanged. A mathematical model considering variable mass effect in interior ballistic and after-effect process is derived, in which the mass and energy transferring process is considered. In addition, a mathematical model describing the relationship between time-delay nozzle gas flow and recoil force is established. The effects of some structural parameters on recoil-reduction efficiency are studied through simulation. The results show that the time-delay nozzle flow device can provide sufficient anti-recoil impulse, and can reduce the recoil force effectively while has less effect on the initial velocity. Key

Key words: ordnancescienceandtechnology, artillery, recoilreduction, nozzleflow, dynamicsimulation