Numerical study of hydrodynamic loads at early stage of vertical high-speed water entry of an axisymmetric blunt body
Numerical study of hydrodynamic loads at early stage of vertical high-speed water entry of an axisymmetric blunt body
复制标题
轴对称钝体垂直高速入水初期水动力载荷数值研究
DOI：
10.1063/1.5121283
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Liu Hua
中科院分区：
文献类型：
--
作者：
Hong Yao;Wang Benlong;Liu Hua
本文对平底圆柱体在高速撞击速度下垂直入水进行了数值研究。多相流求解器基于简化的五方程模型，采用压力松弛法。流体被假定为无粘性和可压缩的。由于弗劳德数高，加载周期短，重力的影响可以忽略不计。通过数值试验，研究了撞击速度和掺气效应对砰击载荷的影响。结果表明，随着冲击速度的增加，流体的可压缩性是重要的，并且声压低估了最大冲击压力。此外，随着掺气水平的增加，冲击载荷和影响面积都将减小。基于激波跳跃关系，提出了简化的理论方程来预测最大冲击载荷，与数值结果吻合较好。量纲分析结果表明，纯水和掺气水中的冲击载荷与马赫数的关系相同，可以用来测量掺气水中较低冲击速度下的高速冲击力。本文对平底圆柱体在高速冲击速度下的垂直入水进行了数值研究。多相流求解器基于简化的五方程模型，采用压力松弛法。流体被假定为无粘性和可压缩的。由于弗劳德数高，加载周期短，重力的影响可以忽略不计。通过数值试验，研究了撞击速度和掺气效应对砰击载荷的影响。结果表明，随着冲击速度的增加，流体的可压缩性是重要的，并且声压低估了最大冲击压力。此外，随着掺气水平的增加，冲击载荷和影响面积都将减小。基于激波跳跃关系，提出了简化的理论方程来预测最大冲击载荷，与数值结果吻合较好。量纲分析结果表明，冲击载荷对结构的力学性能影响很大。
The vertical water-entry of a cylinder with a flat bottom at a high-speed impact velocity is investigated numerically in this paper. The multiphase solver is based on the reduced five-equation model and adopts a pressure relaxation method. The fluid is assumed as inviscid and compressible. The effect of gravity is neglected because of the high Froude number and short loading period. A series of numerical experiments are conducted, and the influence of the impact velocity and aeration effect on the slamming loads are studied. The results show that the compressibility of the fluid is important as the impact velocity increases and the acoustic pressure underestimates the maximum impact pressure. Moreover, as the aeration level grows, both the impact loads and the affected area will decrease. Simplified theoretical equations based on the shock jump relation are proposed to predict the maximum impact loads, showing a good agreement with the numerical results. The dimensional analysis results show that the impact loads in pure and aerated water follow the same relation vs Mach number, which can be used to measure the high-speed impact force at a lower impact velocity in aerated water.The vertical water-entry of a cylinder with a flat bottom at a high-speed impact velocity is investigated numerically in this paper. The multiphase solver is based on the reduced five-equation model and adopts a pressure relaxation method. The fluid is assumed as inviscid and compressible. The effect of gravity is neglected because of the high Froude number and short loading period. A series of numerical experiments are conducted, and the influence of the impact velocity and aeration effect on the slamming loads are studied. The results show that the compressibility of the fluid is important as the impact velocity increases and the acoustic pressure underestimates the maximum impact pressure. Moreover, as the aeration level grows, both the impact loads and the affected area will decrease. Simplified theoretical equations based on the shock jump relation are proposed to predict the maximum impact loads, showing a good agreement with the numerical results. The dimensional analysis results show that the impa...