【摘要】 基于LS-DYNA软件中的ALE算法,对近水面水下爆炸气泡脉动过程进行数值模拟并与实验结果进行对比,验证了近水面近壁面混合边界有限元模型和参数设置的正确性。设置不同爆炸工况,对气泡及其破碎兴波对浮动冲击平台影响进行探究,结果表明:在水下爆炸过程中,气泡、自由面、浮动冲击平台会发生强烈的耦合作用,在气泡脉动阶段,气泡会诱导出涌流和水冢效应,影响浮动冲击平台的安全性和使用性;冲击波是影响浮动冲击平台冲击环境的主要因素,由于气泡的低频性,气泡脉动及水冢对浮动冲击平台的直接冲击作用,会小幅度增加浮动冲击平台冲击环境的谱速度值、谱位移值,对谱加速度值几乎无影响;水冢抨击水面所形成的波浪和气泡破碎兴波,对浮动冲击平台造成的激励载荷呈周期性,其周期与波浪周期相同。波浪的激励载荷仅通过激励其对应频率的浮动冲击平台共振来改变平台的冲击环境。波浪载荷很小,对浮动冲击平台的冲击环境影响较小。更多还原

【Abstract】 Based on the ALE algorithm in LS-DYNA software, the numerical simulation of the pulsation process of underwater explosion near water surface is carried out and compared with the experimental results. The correctness of the finite element model and parameter setting of the near-wall hybrid boundary near the water surface is verified. The different explosion conditions are set up, and the influence of air bubbles and their broken waves on the floating shock platform is explored. The results show that during the underwater explosion, the bubble, free surface and floating shock platform will have strong coupling effect,in the bubble pulsation stage. The bubble will induce the inrush current and the water ripple effect, affecting the safety and usability of the floating shock platform; the shock wave is the main factor affecting the shock environment of the floating shock platform. Due to the low frequency of the bubble, the bubble pulsation and the water ripple on the floating shock platform The direct shock effect will increase the spectral velocity value and spectral displacement value of the shock environment of the floating shock platform to a small extent, and has almost no effect on the spectral acceleration value; the waves and bubbles formed by the water slamming water surface are broken and waved, which is caused by the floating shock platform. The excitation load is periodic with the same period as the wave period. The excitation load of the wave changes the shock environment of the platform only by exciting the floating shock platform resonance of its corresponding frequency. The wave load is small and has little shock on the shock environment of the floating shock platform.更多还原