Implosion of a spherical shock wave reflected from a spherical wall
Implosion of a spherical shock wave reflected from a spherical wall
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DOI：
10.1017/s0022112005003587
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发表时间：
2005-05-10
影响因子：
3.7
通讯作者：
Takayama, K
中科院分区：
文献类型：
--
作者：
Hosseini, SHR;Takayama, K
本文叙述了从球形壁面反射的会聚球形激波的实验结果。为了可视化激波后的运动和流场，设计并制作了一个内带球形腔的丙烯酸PMMA（聚甲基丙烯酸甲酯）非球面透镜状透明试验台。该测试部分使准直物体光束的光流可视化成为可能。叠氮化银球团的能量为1.9 ~ 19j，爆炸在球腔中心产生球形激波，能量范围为1.0 ~ 10.0 mg。压力传感器安装在测试段的内壁上，在两点测量压力。球团在两侧同时被点燃或被塑造以产生均匀发散的球形激波。这种球形发散的激波从试验段的球形内壁反射回来，形成会聚的球形激波。采用双曝光全息干涉法和时间分辨高速视频记录技术，实现了冲击波运动的可视化。观察了球面冲击波发散和收敛的传播顺序及其与气体爆炸产物的相互作用。对试验段内爆冲击波的收敛性、加速度和稳定性进行了研究。
The paper describes results of experiments of a converging spherical shock wave reflected from a spherical wall. In order to visualize the motion and the flow field behind the shock waves, an aspheric lens-shaped transparent test section made of acrylic PMMA (polymethyl methacrylate) with an inner spherical cavity was designed and constructed. This test section made optical flow visualization with collimated object beams possible. Spherical shock waves were produced at the centre of the spherical cavity by explosion of silver azide pellets ranging from 1.0 to 10.0 mg with corresponding energies of 1.9 to 19 J. The charges were ignited by irradiation of a pulsed Nd:YAG laser beam. Pressures were also measured at two points with pressure transducers mounted flush at the inner wall of the test section. The pellet was simultaneously ignited on two sides or was shaped to produce a uniform diverging spherical shock wave. This spherically diverging shock wave was reflected from the spherical inner wall of the test section to form a converging spherical shock wave. We visualized the shock-wave motion by using double exposure holographic interferometry and time-resolved high-speed video recording. The sequence of diverging and converging spherical shock-wave propagations and their interaction with gaseous explosion products were observed. The convergence, acceleration and stability of the imploding shock wave in the test section were studied.