Abstract: A three-dimensional dynamic model of the combustion gasbag rupture projector structure is established to research the rupture of gasbag and its influence on projectile motion during the test of the combustion gasbag. The gasbag rupture jet flow field is simulated by using computational fluid dynamics, and software Fluent the six degrees of freedom equation of rigid body motion is coupled with the fluid governing equation. The variation rule of the internal pressure of gasbag is obtained by comparing the jet flow structure characteristics of free jet and the gasbag rupture jet generated in the dispersal process of submunition. The gasbag rupture jet with different ruptured position at gasbag is simulated, the variation of the internal pressure of gasbag and its influence on projectile motion is obtained. The calculated results show that the existence of the projectile had a great effect on the jet space, and the gasbag rupture jet flow structure is very different from the free jet flow structure. When the gasbag is ruptured at the center position, it has the greatest impact on the internal pressure of gasbag; and when the gasbag is ruptured at the center or at the short side, it has the greatest impact on the attitude of projectile.

Key words: ordnance science and technology, combustion gasbag, gasbag rupture, free jet flow, field structure, motion attitude