碩士 / 國立中山大學 / 海洋環境及工程學系研究所 / 99 / There are four types of oyster aquaculture such as oyster plug rod, horizontal hanging scaffold, pontoon-style longline, and floating raft system. This study is to investigate the mooring tension of an oyster floating raft system under environmental loadings.
According to the hydrodynamic experimental test, the horizontal fluid velocity has a retarded phenomenon when encountering the front part of structure, and then gradually reduces to a stable situation after the second floating rod. The phenomenon is identified as shielding effect for the raft system and has been used as a shielding coefficient to modify the fluid velocity in the computation program. The dynamic analysis of floating raft system under random wave interaction is investigated numerically and experimentally. The lumped mass method is applied to divide the structure into many nodes and elements. A modified Morison equation dealing with moving structure components is used to calculate the environmental forces on the elements. Further, the forces on elements are divided equally into neighboring nodes to form the equation of motion based on Newton’s second law. Finally, the 4th-order Runge-Kutta (RK4) method is used as a time marching scheme to predict the displacement and velocity of nodes for the next time step. The results of time series and spectrum analysis of mooring tension show good agreement between numerical predictions and experimental data. This paper has further expanded to predict the field oyster raft system in an open sea, and offers some useful information to the oyster farmers in terms of improving the structure safety.
| Identifer | oai:union.ndltd.org:TW/099NSYS5282007 |
| Date | January 2011 |
| Creators | Yu-Sing Lian, 連育興 |
| Contributors | chai cheng Huang, 黃材成 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 121 |
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