刚性壁面附近深水爆炸气泡射流特性数值模拟
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摘要
炸药水下近壁面爆炸时,爆炸产物形成的气泡易演化出射流对壁面作用,而气泡射流的特性受多种因素影响。用AUTODYN数值模拟软件计算50 m和300 m水深环境下10 g TNT距100mm刚性壁工况下的气泡射流过程。计算结果表明:用AUTODYN有限元计算软件计算得到的冲击波传播规律、脉动规律与经验公式拟合较好;在气泡脉动收缩结束时射流演化开始,演化过程中的射流将气泡贯穿、形成环形气泡;深水条件下形成的射流速度约350 m/s,远大于浅水条件下的150 m/s,与刚性壁接触后射流头部的压力也大于浅水中的压力;深水条件下近刚性壁测点的压力值均至少高出浅水条件下的5倍,说明深水环境下的射流更易对结构造成严重破坏。研究初步讨论了深水环境下水下爆炸射流的演化特性。
A high speed bubble jet is always formed when an explosive is exploded near a rigid boundary.The characteristics of bubble jet are influenced by many factors. The bubble pulsation and jet evolution of10 g TNT at the depths of 50 m and 300 m at 100 mm from a rigid boundary are simulated by using AUTODYN numerical simulation software. The calculated results show that the shock wave and bubble pulsation can be fit with the empirical formula; the jet is formed at the complete moment of the first bubble pulsation,and the bubble is broken through to form a ring by the jet; the velocity of jet in deep water,which is about 50 m/s higher than that in the shallow water,is about 350 m/s,and the pressure of jet is also higher than that in shallow water; the pressure of measuring point near the rigid boundary in deep water is at least 5 times higher than that in shallow water,which indicates that the jet in deep water may make more serious damage to the structure. The characteristics of jet in deed water explosion are dis-cussed preliminarily.
A high speed bubble jet is always formed when an explosive is exploded near a rigid boundary.The characteristics of bubble jet are influenced by many factors. The bubble pulsation and jet evolution of10 g TNT at the depths of 50 m and 300 m at 100 mm from a rigid boundary are simulated by using AUTODYN numerical simulation software. The calculated results show that the shock wave and bubble pulsation can be fit with the empirical formula; the jet is formed at the complete moment of the first bubble pulsation,and the bubble is broken through to form a ring by the jet; the velocity of jet in deep water,which is about 50 m/s higher than that in the shallow water,is about 350 m/s,and the pressure of jet is also higher than that in shallow water; the pressure of measuring point near the rigid boundary in deep water is at least 5 times higher than that in shallow water,which indicates that the jet in deep water may make more serious damage to the structure. The characteristics of jet in deed water explosion are dis-cussed preliminarily.
引文
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[8]卢熹,王树山,马峰,等.近小尺度壁面水下爆炸射流特性数值模拟[J].弹箭与制导学报,2015,35(3):79-84.LU Xi,WANG Shu-shan,MA Feng,et al.Numerical study on characteristics of underwater explosion jet near small scale wall[J].Journal of Projectiles,Rockets,Missiles and Guidance,2015,35(3):79-84.(in Chinese)
[2]Cole H R.Underwater explosion[M].Princeton,NJ,US:Princeton University Press,1948.
[3]Rayleigh J W.On the pressure developed in a liquid during the collapse of a spherical cavity[J].Philosophical Magazine,1917,34:94-98.
[4]Kucera A,Blake J R.Approximate methods for modelling cavitation bubbles near boundaries[J].Bulletin of the Australian Mathematical Society,1990,41(1):1-44.
[5]Klaseboer E,Hung K C,Wang C,et al.Experimental and numerical investigation of the dynamics of an underwater explosion bubble near a resilient/rigid structure[J].Journal of Fluid Mechanics,2005,537:387-413.
[6]Zhang A M,Cui P,Cui J,et al.Experimental study on bubble dynamics subject to buoyancy[J].Journal of Fluid Mechanics,2015,776:137-160.
[7]杜志鹏,汪玉,辛春亮.水下刚性壁装药爆炸气泡简化模型和数值仿真[J].计算机仿真,2009,26(4):10-13.DU Zhi-peng,WANG Yu,XIN Chun-liang.Simplified bubble dynamic model and numerical simulation of charge underwater explosion on a fixed rigid floor[J].Computer Simulation,2009,26(4):10-13.(in Chinese)
[8]卢熹,王树山,马峰,等.近小尺度壁面水下爆炸射流特性数值模拟[J].弹箭与制导学报,2015,35(3):79-84.LU Xi,WANG Shu-shan,MA Feng,et al.Numerical study on characteristics of underwater explosion jet near small scale wall[J].Journal of Projectiles,Rockets,Missiles and Guidance,2015,35(3):79-84.(in Chinese)