不同边界条件下炸药水中爆炸的能量输出结构

Configuration of explosive energy output in different underwater boundary conditions

针对不同边界条件下,炸药水下爆炸的能量输出结构,设置自由场、沉底、近水底和近水面等不同边界条件水下爆炸实验。结果表明,炸药在距水底、水面一定距离时爆炸,边界条件对冲击波影响较小,对气泡脉动影响较大;当炸药与水底距离小于1倍最大气泡半径处爆炸时,由于水底边界影响,不能形成完整的气泡脉动;当炸药在距水面小于1倍最大气泡半径处爆炸时,气泡直接溢出水面,不能形成气泡脉动压力;当炸药在距水面1～1.5倍最大气泡半径处爆炸时,部分气泡溢出水面,气泡脉动压力较自由场爆炸时小;气泡在膨胀和收缩过程中,由于气泡不断上升,水面对气泡脉动的影响范围要大于水底。

A series of experiments were carried out to explore the energy output characteristics of the explosive in the different underwater boundary conditions： free field,water bottom,near water bottom and near water surface.The experimental results show that when the explosive is near the water bottom and surface,the boundary conditions weakly affect the explosion-induced shock waves and strongly influence the bubble pulsation.When the distance from the explosive to the water bottom is less than the maximum radius of the bubbles,the underwater explosion of the explosive fails to form an integrated bubble pulsation resulted from the water bottom boundary.When the distance from the explosive to the water surface is less than the maximum radius of the bubbles,the air bubbles overflow the water surface and fail to form the bubble pulsation pressure.When the distance from the explosive to the water surface is 1-1.5 times as great as the maximum radius of the bubbles,partial air bubbles overflow the water surface and the corresponding bubble pulsation pressure is lower than that induced by the explosion in the free field.Because of the air bubble rising in its expansion and contraction processes,the influenced range by the water surface on the bubble pulsation is larger that by the water bottom.