舰船水下接触爆炸的SPH算法研究

SPH algorithm to deal with the problem of underwater contact explosion of warship

舰船水下接触爆炸问题涉及多相物质耦合,而且密度分布极不均匀,阻抗严重不匹配,大变形,强冲击等因素都使传统数值算法很难进行数值模拟。通过改进传统SPH(Smoothed Particle Hydrodynamics)算法,并将其应用于水下接触爆炸问题:提出变光滑长度的链表搜索算法,提高了计算效率,也保证了计算精度;总结了SPH方法对密度极大不均匀问题处理思想;研究了SPH方法的前、后期处理技术,提高了对问题的处理能力,增加了计算结果的可视性。验证了所提出的理论和方法的有效性和可行性。另外,分析了不同粒子间距比对数值模拟的影响,结果表明,当粒子的间距比小于2∶1时数值结果相对稳定,等于5∶1时数值计算崩溃。

The problem of underwater contact explosion of warship involves muhiphase materials, extremely nonuniform density distribution, and serious impedance mismatch, at the same time, large deformation, strong shock and other factors make it difficult to be simulated by traditional numerical algorithms. The paper aims to improve the traditional SPH algorithm, and apply it to underwater contact explosion of warship. The linked-list search algorithm with variable smoothing length was proposed, not only to improve the computational efficiency but also to guarantee the accuracy. Meanwhile, the mechanisms of dealing with non-uniform density problems were summarized and the pre-treatment and post-processing to improve the capacity of dealing with difficult problems and visibility were studied. Finally, the underwater contact explosion was simulated successfully, and the results are consistent with the theoretical ones, which verify the effectiveness and feasibility of the proposed method. Besides, the influence on numerical simulation of different particle spacing was analyzed, which shows that when particle spacing is less than 2： 1, numerical results are relatively stable, but it collapses when particle spacing is 5： 1. Key words：