关键词: 固体火箭发动机;绝热层;三元乙丙;粒子;烧蚀

Abstract: Based on ablation experimental motor which can regulate the values of particle concentration,particle impact velocity and particle impact angle,experimental investigation has been conducted on the ablation of EPDM insulator under particles erosion and overload condition.The results show that:(1) A threshold velocity of the impacting particles exists.When the impacting velocity is below the threshold value,the influence of particle concentration,particle impact velocity and particle impact angle on charring ablation rate is small.But when above it,charring ablation rate increases rapidly as the increase of impacting velocity and particle impact angle also plays a very important role as well.(2) The surfaces of charring layer are flat during the weak impacting conditions,while lots of large size particles are attached to the surface of charring layer and the structures are looser than others in particle deposition conditions.During the conditions of severe impacting,particles could not stay on the surface of the charring layer due to their high velocities.(3) A compact/loose structure exists in the charring layer when the impacting velocities are above the threshold value.While an integral impact structure is found when the impacting velocities are under the threshold value.(4) The empirical formulas,accounting for the relationship between charring ablation rate and particle erosion conditions including particle velocity,particle concentration and particle impact angle,are obtained by multiple regression.

Key words: Solid rocket motor (SRM);Insulator;EPDM;Particles;Ablation