中文摘要：

采用高速摄影方法在实验水箱中获得了长径比为3.35~6.75的柱形PETN炸药水中爆炸气泡脉动的图像，进而结合真实的爆轰过程和Rayleigh气泡运动方程，研究了气泡的形态演变规律。研究结果表明，柱形装药在水中爆炸时，形成的初始气泡的形状为非球对称形，这种非对称特征随长径比的增加而增大。气泡表面的运动也表现出明显的非球对称特征，气泡表面在装药径向的膨胀运动呈指数衰减，在装药轴向两端的膨胀运动更接近于分段线性衰减。气泡表面的不对称运动与柱形装药水下爆炸的能量输出结构不均有关，与冲击波的有效能量分布规律是相似的。

英文摘要：

Oscillation images of underwater explosion bubbles generated by cylindrical PETN with length to diameter ratio from 3.35 to 6.75 are conducted in a water tank by using high-speed photography technology. Bubble shape evolution is investigated by involving real detonation processes and Rayleigh-Plesset function. Results show that the initial bubble has an asymmetric shape, and the asymmetry is enhanced as the length to diameter ratio increases. The bubble-water interface expansion motion at the side of the charge exhibits an exponential decay, while along the charge axis the decay tends to piecewise linear, both differ from the Rayleigh bubble. These differences are potentially attributed to the asymmetric energy structure of cylindrical charge, which is similar to the usable energy distribution of a cylindrical charge underwater explosion shock wave.