| CFD method is implemented in use of FLUENT software to solve some interesting hydrodynamic problems relating to the ocean engineering in this thesis. And several advantages of this approach are showed, such as independent to the physical and experimental models, flexibly in actual problems, which could fulfill the actual needs in engineering projectsA 2D numerical wave tank is build up, and some numerical analyses are carried out with comparisons of analytical solutions to study its efficiency. Other technique details, such as the turbulence coefficients setting method, moving mesh technique, and time step determination, are also illustrated in this thesis. It can be seen obviously from the results that: both the wave-making and wave-absorbing ability of this numerical wave tank are excellent, which suggests that the numerical wave tank could be used to research the waves/structures interaction problems.2-D and 3D radiation problems are all simulated successfully in this thesis. The oscillating motions of a three dimensional body are revealed using the moving mesh technique, added mass and damping coefficient of the body are also obtained. The numerical models,meshing and slove procedure in use of FLUENT are introduced.Then the discussion of factors that might affect the final solution is given, such as the way of setting coefficients, meshes, oscillating frequencies, and the control domain. The result certifies the feasibility of obtaining the added mass and damping coefficient based on Fluent. Additionally, cases related to the 2D diffraction problems are also studied, and nonlinear effects of the second order, especially the sum-frequency wave forces, are analyzed.The study shows that simulation of wave radiation and diffraction problems based on Fluent is feasible. A thorough study of the key technologies used to solve the hydrodynamic problems is carried out. And numerical experiences are also calculated, which benefits the further research. |
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