Development And Application Of Mooring System Analysis Module In Numerical Tank Based On OpenFOAM

With the gradual development and utilization of marine resources in the deep sea,research on floating structures and its mooring systems has become a research hotspot in the field of ocean engineering.Computational fluid dynamics has a powerful numerical simulation capability and is widely used in practical engineering projects.It has become an indispensable research method in the field of marine engineering design.This paper is based on the open source toolbox OpenFOAM,numerical wave tanks and mooring systems are developed,provided a new tool for the study of hydrodynamic characteristics of floating structures.First of all,in order to build a numerical wave tank that can create a variety of wave conditions,this paper expanded the wave-making and wave-eliminating capabilities of the waves2 Foam solver and the interDyMFoam solver,and compared the calculation efficiency and accuracy of numerical wave tank between different wave-making methods and wave-eliminating methods.Based on the velocity entry method and relaxation zone,simulation and verification of regular waves and irregular waves are performed.The force of different diameter cylinders under wave condition were studied and compared with theoretical solution,the reliability of numerical wave tanks is proved.Then,based on OpenFOAM's sixDoFRigidBodyMotion module,the static analysis program of the mooring system was developed using the catenary equation and piecewise extrapolating method respectively,thus coupled solution between floating structure and its mooring system was implemented.A floating breakwater under typical conditions was simulated.The numerical simulation results under regular wave were compared with the experimental data of other scholars,and this further verified the effectiveness of the mooring systems.Finally,a two-dimensional simplified semi-submersible platform(I-shaped structure)is considered as the research object.the structural motion responses and the force of the mooring system under wave slamming loads were simulated.The slamming loads of the column and deck were analyzed,and the relationship between the slamming load and the relative velocity of the I-shaped structure was discussed.