水下航行器内孤立波载荷形成机理数值模拟研究

Numerical simulation study on the formation mechanism of internal solitary waves loads acting on a underwater vehicle

弄清水下航行器内孤立波载荷形成机理是分析内孤立波对航行性能影响和控制研究的基础和前提。采用数值模拟方法深入分析模型位于内孤立波波面上方、穿越波面、位于波面下方3种情形下,模型受内孤立波流场水动力作用和分层密度差静力作用过程,对比不同潜深时纵向力、垂向力和俯仰力矩特性差异。研究表明,穿越波面的情况下,模型所处的流体密度变化,起了决定性作用,垂向力比纵向力大一个量级;穿越波面时,艏艉浮力不平衡,俯仰力矩有极大值和极小值出现;模型始终位于波面上方或下方时,受内孤立波流场的影响,其水动力性能也产生了明显的变化。

Clarifying the mechanism of the formation of internal solitary wave loads on underwater vehicles is the basis and prerequisite for the analysis of the impact of internal solitary waves on navigation performance and control research.In this paper,numerical simulations are used to analyze the processes of the hydrodynamic generated by flow filed and statics generated by density difference processes acting on the model under three scenarios:above the wave surface,across the wave surface and below the wave surface,and to compare the differences of longitudinal force,vertical force and pitching moment at different depths.The results show the change of fluid density where the model is located plays a decisive role in the case of crossing the wave surface,and the vertical force is one order of magnitude larger than the longitudinal force;the head and tail buoyancy forces are unbalanced,producing extreme and minimal values of the pitching moment,respectively.when the model is always located above or below the interface,the hydrodynamic is also significantly changed by the internal solitary wave flow field.