水下近自由面爆炸过程中的多相流运动特性研究  

Motion characteristics of multiphase flow in underwater explosion near free surface

作　　者：余俊[1,2] 王海坤 刘国振[1] 郝轶 张得扬[1] YU Jun;WANG Hai-kun;LIU Guo-zhen;HAO Yi;ZHANG De-yang(China Ship Scientific Research Center,Wuxi 214082,China;Taihu Laboratory of Deep-sea Technological Science,Wuxi 214082,China)

机构地区：[1]中国船舶科学研究中心,江苏无锡214082 [2]深海技术科学太湖实验室,江苏无锡214082

出　　处：《船舶力学》2023年第2期163-172,共10页Journal of Ship Mechanics

摘　　要：水下近自由面爆炸现象涉及到爆轰气体产物、水以及空气等多种流体之间的相互作用过程,同时还伴随有明显的汽液两相之间的相变转换。为了理解和掌握近水面爆炸过程中的多流体非线性耦合特性,引入基于相变转换的多相可压缩流体计算模型进行分析。采用一维激波管问题对计算模型的精确性和收敛性进行测试验证,在此基础上利用二维轴对称模型模拟近水面爆炸过程,获得冲击波传播、空化产生与溃灭、爆炸气泡运动等过程。爆炸气泡运动的计算结果与试验结果具有一致性。对于由水下爆炸引起的近自由面空化现象,数值模拟清晰展示了空化域的产生、发展及其溃灭的完整过程。空化域由开始的单连通域演化为涡环形态,并向外扩展直至完全溃灭。将蒸汽体积分数0.5‰作为空化域的识别判据时,计算获得的空化域的演化过程与试验结果较为一致。数值模拟结果还进一步揭示了空化域内部的一些重要的物理特性,本文的研究结果能够为水面舰艇结构的抗爆抗冲击防护研究提供技术支撑。Underwater explosion(UNDEX) near free surface involves the interaction between detonation gas products, water, air and other fluids, and also contains obvious phase transition. This interaction is a typical multiphase compressible fluid movement problem with phase effect, which is very nonlinear and difficult to study. In order to understand and master the nonlinear interaction characteristics of multi-component in underwater explosion near free surface, a compressible multi-phase fluid model based on phase transition was introduced. The control system equations of the model were solved by a simple fractional step approach,which was divided into hyperbolic step and relaxation step. A MUSCL-Hancock method with HLLC approximate Riemann solver was applied to discretize the homogenous hyperbolic equations in hyperbolic step, and the nonlinear system was solved by Newton-Raphson iterative method in the following relaxation step. The accuracy and convergence of the numerical model were tested and verified by using the 1D shock tube example. On this basis, underwater explosion near free surface was simulated by using the 2D axisymmetric model,and the process of shock wave propagation, cavitation generation and collapse, and explosion bubble motion were clearly captured. For the explosion bubble movement, the numerical results of bubble interface are in good agreement with the experimental results. For the cavitation near free surface caused by underwater explosion, numerical simulation clearly shows the generation, development and collapse of the cavitation. The cavitation domain evolves from the initial single connected domain to the vortex ring form and expands outward until it completely collapses. When the vapor volume fraction is greater than 0.0005(the identification criterion of cavitation domain), the numerical results of cavitation evolvement are consistent with the experimental results. The numerical results further reveal some important physical properties in the cavitation domain, which can provide some tech

关 键 词：水下爆炸 爆炸气泡 空泡 可压缩流体 相变转换 空泡溃灭 

分 类 号：O359[理学—流体力学] O383[理学—力学]