Study on Numerical Wave Tank and Simulation of a Marine-Vehicle Motion in Waves

• Main Authors: Lin, Chuncheng, 林俊成
• Other Authors: Liu, Tsunglung
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/32018599079194162387

博士 === 國防大學理工學院 === 國防科學研究所 === 100 === The wave motion is complicated physical phenomenon. Due to the interaction between the weather, ocean currents, seabed topography and gravity, the ocean wave always appears with various features. The numerical wave tank (NWT) can be considered as the ocean engineering research tool that requires the least manpower and material resources. The numerical wave tank can be used to simulate the motion of ocean waves and marine vehicles or to assist harbor design. Therefore, this study employs the finite volume method (FVM), the dynamic mesh technique (DMT), the volume of fluid (VOF) model, and the wave damping zone skill to construct a NWT so as to study the physical behavior of numerical waves. Additionally, the axises of this study were divided into three parts: the first part is to reveal the dynamic properties of ocean waves then developing the NWT technologies. In this study, the piston-type wave-maker was applied to generate numerical waves. In order to enhance the numerical waves accuracy of NWT, the studies included the treatment of reflection wave from the boundary of the computational domain, alteration of the stroke range of the wave maker, and tested different numerical schemes for wave-profile prediction. The second part is ensure the progressive wave profiles correctly, then used the Taguchi Method DOE, the Neural Network Design and the Genetic Algorithms Technology for robust design in NWT. In this study the wave height has been set up as the quality of characteristic which could be applied to discussion of the influence of the wave parameters regarding to the wave generation. The results of this study will lead to a better understanding of physical behavior of the wave-maker which could further help the researchers to enhance the computational capability for the study of marine structure dynamics in waves. The third part is tested for wave generation and NWT technology have been further applied for the study of the wave-body interactions. However, through the different simple configuration such as square and sphere, etc, those could be float-body and simulated the 2-dimensional and 3-dimensional wave-body interaction studies in NWT. Meanwhile, the results were presented by visualable figures and discussed the reasonability compatible with physical phenomenon. Finally, this paper used a series research methods to develop the NWT and simulate the wave-body interactions. These methods not only can discuss and analyze the numerical results deeply, but also can be widely used in ocean engineering field. While this study has its limitations, it is hoped that it can serve as a basis for further study in numerical simulation methods.