Research on Load Characteristics of Underwater Submersibles Under Action of Internal Solitary Wave

In order to clearly understand the force characteristics of underwater vehicles under the action of solitary waves in the ocean, it is necessary to address the phenomenon of submarines losing control and falling deep when encountering internal solitary waves during underwater navigation. By solving the Reynolds-averaged Navier-Stokes (RANS) equations to described the flow field characteristics and obtain loads on the underwater fixed submersible Suboff, employing the velocity inlet method to generate internal solitary waves (ISW), a three-dimensional numerical tank for ISW is established. By comparing the publicly published experimental results of finite length cylinders under internal wave action, the effectiveness of the numerical model in this paper is verified. This model was used to simulate a large number of numerical examples, analyzing the influence of parameters such as submersible depth, internal wave amplitude, and upper and lower fluid thickness stratification ratio on the mechanical characteristics of the submersible, which explains the essential reasons for the force variation of fixed submersible in ISW. Research has shown that the relative depth of the submersible relative to the internal waves is a key parameter affecting the force characteristics of fixed submersibles, especially for submersibles which do not pass through the wave surface, their vertical load amplitude is only 3% of that of submersibles which completely pass through the wave surface; Secondly, when the submersible can completely pass through the internal wave surface, the influence of parameters such as wave amplitude and fluid stratification ratio on the amplitude of the submersible load is not significant, while mainly affects the duration of the load. The results can provide theoretical and technical support for the safety of underwater submersibles under action of ISW.