In-situ study of the floating raft system for oyster aquaculture

• Main Authors: Chun-Ho Chan, 詹竣合
• Other Authors: Chai-Cheng Huang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/71336719558534748137

碩士 === 國立中山大學 === 海洋環境及工程學系研究所 === 101 === Oysters not only are delicious but also enriched with nutrition; thus, they have being loved for generations. The main oyster aquaculture sites spread along the southwestern coastal regions of Taiwan. The oyster raft made by a lot of bamboo and Styrofoam has about 2-year life span. They are frequently abandoned in the coastal areas and cause serious environmental problem. Thus this project intends to investigate the capability of a set of oyster raft against current and waves and improve its durability in the field. The numerical model is established based on the lumped mass method as well as the modified Morison equation by calculating the drag and inertia forces on each element. Then 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 sea-states are treated as the combination of many linear waves, and assume that Goda modified JONSWAP spectrum is good for the present study. Only design sea-state conditions are needed to input in the numerical model to generate the dynamic results of interaction of fluid and structure. Two instruments such as ADCP (Acoustic Doppler Current Profiler) and tension gauge are deployed in the field test to measure the wave/current data as well as the mooring line tension. The comparisons of numerical tension results and the in-situ measurements show a good agreement. With this validation, a correct numerical model was established and is ready for applying to any in-situ raft system for planning or design purposes.