• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1575-1580
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• 2010

Recently, the development of bio-mimetic underwater vehicles that can emulate the characteristic movements of marine fish and mammals has attracted considerable attention. In this study, the motion of the batoid (i.e., cownose ray) fin that facilitates excellent cruising and maneuvering during underwater movement has been studied. The velocity achieved and distance covered with each fin movement are numerically studied. A fluid-structure interaction method is used to perform 3D time-dependent numerical analysis, wherein an adaptive mesh is employed to account for the large deformation of a fin interacting with a fluid. The results of a preliminary study show that the thrust of a ray fin is highly dependent on the frequency. Further, once the fin amplitude required for generating a given thrust is evaluated for the conditions experienced by an actual ray, the frequency and amplitude values for achieving better thrust are determined.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.403-412
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• 2019

The characteristics of the manoeuvring motion of a ship are dependent on the ship type, as well as draft or speed in the same ship. In recent years, the number of extra-large vessels has increased significantly, which can cause enormous material and environmental damage in the event of a marine accident. Thus, the importance of ship maneuvering is increasing. The IMO has forced the officers to be trained in simulators through the STCW 95 amendment. However, FMSS is costly and difficult to access and the PC-based simulator has the disadvantage that only one person can engage in simulation. The purpose of this study was to solve the shortcomings of the FMSS and PC-based simulators by enabling multiple people to use their PCs to simulate based on a network. The simulator is implemented through the analysis and numerical calculation of the Nomoto model, Radar function mounting, data transfer protocol design, and GUI building. To verify the simulator, the simulation results were compared and analyzed with the test results of T.S. HANBADA according to the criteria of the Korean Register of Shipping(KR) and IMO standards for ship maneuverability. As a result, It showed a relative error of 0%~ 32.1% with an average of 13.7%, and it satisfied the IMO criteria for ship maneuverability.