不同底质条件下近海底爆炸冲击波载荷特性研究

Load Characteristics of Underwater Explosion Shock Wave near Seabed Charge Projectile

近海底爆炸冲击波会对海底光缆、海底管道等设施造成严重的破坏,不同底质条件的冲击阻抗会影响冲击波的时空演化规律,因此,研究不同底质条件下近海底爆炸冲击波载荷具有重要的意义。基于耦合欧拉-拉格朗日方法建立近海底爆炸模型,探究海底底质对近海底爆炸冲击波载荷的影响,结果显示:测点角度在20°~50°范围内时,海底底质材料会显著影响冲击波峰值压力,近海底反射的影响随爆距比的增加而增强,当测点角度超出该范围时,该现象逐渐消失;海底底质影响范围不随底质的变化而变化,但是在不同底质条件下,受影响区域的反射系数截然不同,当海底底质较软时,海底底质影响区域内的冲击波反射系数在0.81~1.05之间,当海底底质为刚壁时,海底底质影响区域内的冲击波反射系数在0.98~1.33之间;水深不会导致冲击波峰值压力发生显著变化。

The near-seabed explosion shock wave can cause serious damage to such facilities as submarine optical cables and pipelines.The spatiotemporal evolution of the underwater explosion shock wave can be affected by the impedance of different types of substrate.Therefore,it is of great significance to study the near-seabed explosion shock wave load under different substrate conditions.Based on the coupled Eulerian-Lagrangian(CEL)method,a numerical model of near seabed explosion is established to investigate the effect of seabed material on the shock wave load of near seabed explosions.The results show that the seabed material significantly affects the peak pressure of the shock wave within a certain range of measuring point angles of 20°–50°.The reflection effect of the near seabed increases with the increase of the explosion distance ratio within a certain range of measurement point angles of 20°–50°.When the measurement point angle exceeds this range,this phenomenon gradually disappears.The effect regions of these two types of seabed sediment are similar while their reflection coefficients are significantly different.When the seafloor sediment is soft,the reflection coefficient near seafloor ranges from 0.81 to 1.05.However,when the seafloor sediment is hard,the reflection coefficient near seafloor ranges from 0.98 to 1.33.The water depth has little effect on the peak pressure of the shock wave.