水下爆炸冲击波和气泡行为自由面效应的实验研究  

Experimental research on the free surface effect of shock wave and bubble behavior of small yield underwater explosion

作　　者：方厚林[1] 卢强[1] 郭权势 李国亮 刘存旭 陶思昊 张德志[1] FANG Houlin;LU Qiang;GUO Quanshi;LI Guoliang;LIU Cunxu;TAO Sihao;ZHANG Dezhi(Northwest Institute of Nuclear Technology,Xi’an 710024,Shaanxi,China)

机构地区：[1]西北核技术研究所,陕西西安710024

出　　处：《爆炸与冲击》2024年第8期147-158,共12页Explosion and Shock Waves

摘　　要：为研究自由面对水下爆炸冲击波、气泡行为和由气泡与自由面强耦合作用形成水幕的影响,设计了小当量PETN球形装药近水面水下爆炸实验系统,开展了5种典型工况水下爆炸实验,采用高速相机和压力传感器分别获取了气泡和水幕形态演变过程、水中测点压力时间历程。根据冲击波、气泡时序特征分别分析了其自由面效应,冲击波主要变现为截断效应,气泡与自由面相互作用表现为复杂的气泡形态演化和水幕生成及演化,通过高速图像结合压力时间历程分析,进一步从气泡水平半径、中心偏移位移和水幕最大高度定量分析气泡自由面效应。结果表明:随着爆深的减小,水面反射波程差减小,自由面对冲击波的截断效应增强,即冲击波正压作用时间减小,实测截断时间差与计算时间差的最大偏差为6.81%;随着比例爆深减小,自由面效应加剧,气泡和水幕形态趋于复杂化;气泡由球形演变为卵形以及更加复杂的形态,水幕由单一的水冢,逐渐转变为水冢-顶端飞溅水柱、水冢-垂直喷射水柱-水射流等复杂形态;气泡水平半径从第2个脉动周期不再保持脉动特征过渡到第1个脉动周期,甚至到第1次气泡膨胀阶段;气泡水平半径中心偏移位移呈现出两段式变化规律,在前期偏移位移快速增加阶段(偏移位移范围0~20 mm),4种比例爆深偏移位移呈现出近似线性变化规律,线性系数相近。In order to study the effects of free surface on underwater explosion shock wave,bubble behavior and water plumes formed by strong coupling between bubble and free surface,a small yield pentaerythritol tetranitrate(PETN)spherical charge near water surface underwater explosion experimental system was designed,five typical conditions of underwater explosion experiments were carried out,and the evolution process of bubble and water plumes,as well as time history of pressure at the gauge were obtained by high-speed camera and pressure sensor respectively.Based on the characteristics of shock waves and bubble time series,their free surface effects were analyzed separately.The shock wave mainly manifests as truncation effects.The interaction between bubble and free surface is manifested as complex bubble evolution and water plume generation and evolution,which were mainly analyzed through high-speed images,appropriately combined with pressure values.The free surface effects of the bubble were further quantitatively analyzed by the horizontal radius of the bubble,the offset displacement of the bubble,and the maximum height of water plume.The results show that with the decrease of the detonation depth,the difference of the surface reflection wave path decreases,and the truncation effect of the free surface on shock wave increases,that is,the time of the positive pressure of shock wave decreases,and the maximum deviation between the measured truncation time difference and the calculated time difference is 6.81%.With the decrease of the scaled detonation depth,the free surface effects increase,and the shapes of bubble and water plumes become more complicated.The bubble evolves from a sphere to an oval shape,even more complex shapes.The water plume gradually changes from a single water spike to a complex form such as a water spike-top splash column,a water spike-vertical jet column-water jet,etc.The change of the horizontal radius of the bubble no longer retain pulsation characteristics from the second pulsation period to t

关 键 词：水下爆炸 冲击波 气泡行为 自由面效应 

分 类 号：O382.1[理学—流体力学]