摘要:
本文对柱面两极点起爆情况下滑移爆轰波驱动两层金属飞层对碰凸起和微射流形成进行了模拟研究。铅飞层内界面走时计算结果与实验结果能够较好符合。在两极位置铅飞层内部出现断裂并形成空腔，内壁面则形成鼓包型凸起；在赤道位置飞层内壁面凸起后断裂产生大尺度金属颗粒，其和微喷射形成的小尺度颗粒叠加构成了对碰区凸起现象。在铅飞层内表面微喷射现象的研究中发现，两极附近的微喷物质最大速度逐渐下降，而对碰区附近的微喷颗粒最大速度反而随时间逐渐增高。之后，通过设计沟槽型微喷计算模型，验证了在两极和赤道上铅飞层内表面产生的初始微喷射最大速度能够由同一均匀缺陷表面所产生。最后，通过数值模拟分析研究初步给出了该问题中抑制金属飞层对碰凸起和微喷现象的方法。
Abstract:
In the cylindrical implosion problem, the phenomenon of colliding bulge and surface micro-jet formation of two-layer metal flyers, which are driven by two slip detonations in opposite direction of the pole, is studied by simulation using Euler’s program. Simulation results of the inner surface travel times of the lead flyer coincide well with the experimental results. In the polar position, there is a fracture cavity in the lead flyer, and a blunt bulge is formed on the inner surface. At the equator, large-scale fracture particles are generated as the inner surface of the lead flyer is growing. It is considered that the colliding bulge at the equator which seem to be continuous in the X-ray images is actually discontinuous, and it is composed of large-scale fracture particles and small-scale micro-jet particles. By analysis of the inner surface position on the optical images at different times, the maximum velocity of the lead micro-jet particles is obtained. It is found that the maximum velocity of the micro-jet particles is declined in the pole region, but at the equator its maximum velocity is increased with time. It is considered that the subsequent loading waves on the colliding bulge area may cause higher speed of micro-jet particles than the first loading wave. And then, the groove micro-jet model of the lead, which is loaded by impact, is used to be equivalent to the uniform disfigurement surface micro-jet. It is proved that both the micro-jet maximum velocity in the pole region and the velocity at the equator can be formed by the same uniform disfigurement surface, and the correctness of the experimental optical image is also verified. Finally, the restrained method of the colliding bulge and surface micro-jet in this problem is studied by simulation. The micro-jet maximum velocity of the lead flyer can be declined by changing the two opposite initiation points to the points close to the metal flyers in the pole region, and the main cause of collision bulge at the equator is that the Mach reflection is formed in the collision area because of the low sound velocity of lead.
首页
登录
注册
下载: