博士 / 國立成功大學 / 造船及船舶機械工程學系 / 89 / ABSTRACT
In the paper, the hydrodynamic problems between two moving ships in waves are analyzed by using a three-dimensional potential theory and the source distribution technique. The potential is presented by a distribution of source over the ship hull. The corresponding Green functions and their derivatives can be solved numerically by using the series expansions of Telste & Noblesse algorithm for the Cauchy Principal value integral of unsteady flow.
At first, the diffraction problems between two moving ships in waves have been analyzed. Two pairs of models, Barge-Ship and Mariner-Series 60, are used for numerical calculations, and comparisons with experimental data and strip theory are made. From the comparisons, it shows that the hydrodynamic interactions are generally important. In the resonance region, the hydrodynamic interaction calculated by 3D method is more reasonable, which is not so significant as that by 2D method.
Next, the radiation problems including the related hydrodynamic coefficients (added mass and damping) were also analyzed. Here with the hydrodynamic interactions, added mass and damping coefficient in some cases are found to be negative while they are always positive for single ship case. After solving exciting forces, added masses and damping coefficients, motions of two ships can be analyzed either with speed or without speed. Again the hydrodynamic interactions between two ships also considered are found to be important for the motion response generally, and the results calculated by 3D method are physically reasonable and the predictions are improved, especially in the resonance region.
Finally the method is extended to solve the relative motions, wave elevation and the nonlinear drift forces and moments between two ships. From the present results, we can conclude that the 3D prediction model developed here is indeed better than the 2D one concerning many physical respects. Because the experimental set-up for two ships moving in waves is rather complicated and difficult to handle, we can only justify the results by some existing data and physical phenomena. However, if the experiments for motion, relative motion, wave elevation and drifting forces and moments between two ships can be made in the future for comparison, the present method will be more rigorous.
| Identifer | oai:union.ndltd.org:TW/089NCKU0345005 |
| Date | January 2001 |
| Creators | Chen, Gung-Rong, 陳光榮 |
| Contributors | Fang, Ming-Fang, 方銘川 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 152 |
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