水下爆炸冲击波壁压理论及数值计算方法改进研究  

An improvement of the wall-pressure theory and numerical method for shock waves in underwater explosion

作　　者：刘晓波 李帅[1] 张阿漫[1] LIU Xiaobo;LI Shuai;ZHANG Aman(College of Shipbuilding Engineering,Harbin Engineering University,Harbin 150001,Heilongjiang,China)

机构地区：[1]哈尔滨工程大学船舶工程学院,黑龙江哈尔滨150001

出　　处：《爆炸与冲击》2022年第1期120-132,共13页Explosion and Shock Waves

基　　金：国家自然科学基金(51709056);中央高校基本科研业务费(3072020CFJ0105);黑龙江省博士后科研启动金(LBH-Q20016)。

摘　　要：水下爆炸冲击波是舰船抗冲击评估中重要的载荷成分,也是水中结构物毁伤程度快速预报的关键和依据。通过小当量实验发现,由于传统Taylor平板理论公式忽略了冲击波波速的非线性变化,导致其在预报近距离水下爆炸冲击波壁压脉宽时出现偏差。为此,给出了比例爆距R/W^(1/3)为0.11~5.30 m/kg^(1/3)(R为爆距,W为炸药质量)下的冲击波速度拟合公式,对传统Taylor理论公式进行修正。修正后,在R/W^(1/3)=0.11 m/kg^(1/3)下,壁压脉宽及冲量偏差大幅减小;在R/W^(1/3)≥0.21 m/kg^(1/3)下,两者偏差均小于12%。此外,在处理水下近场和中远场爆炸问题时,发现数值耗散会导致壁压峰值被明显削弱,于是提出了一种可行的数值策略消除计算中数值耗散导致的削弱效应,结果与修正的Taylor平板理论公式吻合良好,峰值偏差均小于9%。改进后的冲击波壁压理论公式及数值计算方法可为舰船抗爆抗冲击领域提供理论和技术支撑。Underwater blast shock wave is an important load in the evaluation of the impact resistance of ships,and it is also the key and basis for the fast prediction of the structure damage in underwater explosions.In the present study,a series of small equivalent underwater explosion experiments were carried out in the explosion tank.By comparing the theoretical predicted and experimental measured wall pressure characteristics,the applicability of the traditional Taylor formula in predicting the wall pressure of the underwater explosion shock wave was explored.It is found that the deviation of the Taylor plate theory in predicting the pulse width of the wall-pressure is mainly because the nonlinear variation of the shock wave velocity is not considered.Given this,a fitting formula of the shock wave velocity for 0.11 m/kg^(1/3)≤R/W^(1/3)≤5.30 m/kg^(1/3),where R is the detonation distance and W is the charge weight,is given to improve the traditional Taylor theoretical formula.The corrected theoretical values are in good agreement with the experimental values.For R/W^(1/3)=0.11 m/kg^(1/3),the pulse-width deviation of the wall-pressure of the shock wave between the improved Taylor formula and the experimental result is reduced from 79.6%to 26.6%,and the deviation of the impulse is reduced from 119.3%to 58.4%.For R/W^(1/3)≥0.21 m/kg^(1/3),the deviations of the pulse-width and the impulse of wall-pressure are both less than 12%.Moreover,in the simulation of the wall-pressure change at different distances by numerical method(e.g.,finite element method),it is found that the numerical dissipation causes the plate to move in advance(before the arrival of the shock wave front),leading to a significant decrease in the peak of the wall-pressure when dealing with the near-field and far-field underwater explosion problems.Therefore,a feasible numerical strategy was proposed to eliminate the weakening effect caused by numerical dissipation.The improved numerical results are in great agreement with the improved Taylor plate theor

关 键 词：水下爆炸 壁压 冲击波 Taylor平板理论 

分 类 号：O382[理学—流体力学]