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Collaborating Authors
KIOST
Engineering Approach for Cleaning-Up Garbage Patches
Kang, Hee Jin (KIOST) | Ahn, Haeseong (KIOST) | Choi, Jin (KIOST) | Lee, Dongkon (KIOST)
ABSTRACT Much of garbage patches consist of plastics, and most of these plastics are reusable (Werthmann, 2007). Long-lasting plastics that are found in garbage patches contain numerous toxic materials (Teuten et al., 2009). Cleaning up garbage patches involves environmental matters and economic and social factors. Economically speaking, transportation and disposal processes require high costs, which is why the problem will worsen. Socially, the garbage patch affects the health and lives of people those who occupy coasts that border the ocean gyres (Leous et al., 2005 and UNEP, 2011). Thus, various research studies have been performed to improve the garbage patch problem. In this paper, we discuss the use of an FRSO (floating, recycling, storage and offloading) vessel as a novel approach to cleaning up garbage patches. From the point of view that considers garbage patches as a type of a new energy source and raw materials, an FRSO could recycle the debris into oil, gas and raw materials in the ocean over long time periods.
Time Domain Analysis of Arrays of Floating Offshore Wind Structures
Kim, Yunho (KIOST) | Hong, Sa Y. (KIOST) | Nam, Bo Woo (KIOST) | Kim, Byoung W. (KIOST) | Hong, Seok W. (KIOST)
ABSTRACT Wave-induced motion characteristics of multiple Spar-type floaters with elastic connectors and catenary mooring lines have been investigated in time domain. Hydrodynamic coefficients were achieved by using Green function with High-Order Boundary Element Method(HOBEM). Wave diffraction induced by other floaters was confirmed to be negligible as floaters are separated sufficiently. Dynamics of connectors and mooring lines was coupled with the floating solver, while aerodynamics and rotor-dynamics have not been considered yet. First, characteristics of one elastic connector were studied. These values have good agreements with analytic solutions and the commercial code relatively. Numerical calculations for the horizontal array of five wind turbines were conducted in irregular wave conditions. Results were investigated in aspect of motion responses, tensions and bending moments with different sea states.
- North America > United States (0.94)
- Asia (0.68)
- Health, Safety, Environment & Sustainability > Environment (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Mooring systems (0.95)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (0.83)
Effect of Motion Reduction Structures on Motion of Floating Wave Energy Converter
Park, J.Y. (KIOST) | Nam, B.W. (KIOST) | Hong, S.Y. (KIOST) | Shin, S.H. (KIOST) | Hong, K.Y. (KIOST)
ABSTRACT The goal of this study was to optimize the design of motion reduction structures for a floating pendulum-type wave energy converter (WEC) used to harness energy from the ocean. The purpose of these structures was to improve the performance of the WEC by reducing its motion under operating wave conditions and by helping the device absorb wave energy efficiently. Moreover, the motion reduction structures cause wave motion that protects the WEC against direct excitation of wave loads under extreme wave conditions. In this study, motion reduction structures were installed on a floating pendulum WEC that has been the subject of previous studies. The effects of the structures were then analyzed under different incident wave conditions. The design parameters for the motion reduction structures were size, shape, and installed position. The wave-induced motion characteristics and performance of the floating pendulum WEC were investigated numerically. Based on the simulation results, we were able to optimize the motion reduction structure design of the WEC, thus improving its efficiency and durability.
ABSTRACT A series of integrated simulations of a deep-water crane vessel system composed of four sub components, floating vessel, lifted equipment, hoisting cable and dynamic positioning (hereinafter DP) system were carried out by using nonlinear time-domain analysis method. Analysis of coupled dynamics includes the crane vessel and equipment connected via crane wire, and DP under wind, wave and current condition. DP systems were numerically implemented using classical PD feedback controller. Some cases of deepwater installation simulations were conducted to evaluate the global performance of the floating crane vessel combined with DP system.
- North America > United States (0.47)
- Asia > Japan (0.29)
ABSTRACT The floating offshore wind turbines(FOWTs) are considered as a promising candidate due to high-quality of wind energy and environmental friendliness. There are typical three types of conceptual design of FOWTs such as Spar, Semi-submersible, and TLP. Recently, "Hywind-OC3" spar and "WindFloat" semi-submersible type structures as 5MW class have been studied. In the present study, a series of parametric study for several shape design of FOWT have been conducted considering the wide operable water depth by having a shorter draft than one of typical spar and cost effective construction by numerical analysis using a 9-node higher-order boundary element method(HOBEM). In the parametric study, the wind turbine platform which has the truss spar type shape with damper structure to reduce the motion & acceleration responses is suggested. The numerical results for the selected shape design of FOWT were validated through a series of convergence test and model test data. In the series of model tests at ocean engineering basin, MOERI/KIOST, motion and acceleration at Nacelle responses were obtained for regular and irregular waves. The global performance of the model structure has been compared with same class spar-type structure, 5MW Hywind-OC3. Finally, a shape design of FOWT to get more improved global motion performance and technical feasibility was also discussed.
- Europe (1.00)
- South America > Brazil (0.28)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Sustainable development (1.00)
- Health, Safety, Environment & Sustainability > Environment (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
- Facilities Design, Construction and Operation > Facilities and Construction Project Management > Offshore projects planning and execution (0.71)
Preliminary Results of Global Performance Evaluation of a FPSO Designed for Mexican GoM
Hernandez, A.O.V. (Instituto Mexicano del Petrรณleo) | Hernandez, J. (Instituto Mexicano del Petrรณleo) | Molina, O.V. (Instituto Mexicano del Petrรณleo) | Sung, H.G. (KIOST) | Cho, S.K. (KIOST) | Hong, K.Y. (China National Petroleum Corporation)
ABSTRACT This paper presents a comparative study of FPSO model tests and numerical analyses that have been carried out for a joint project between KIOST and IMP. With a proposed design of FPSO for Mexican GoM (Gulf of Mexico), IMP and KIOST have been collaborating with each other. IMP proposes a FPSO which is aimed for environmental conditions of Mexican GoM. For evaluation of global performance of the FPSO, IMP carries out numerical analysis while KIOST does the model testing. The first part of the project is focused upon the hydrodynamic performance of the vessel motion and coupled analysis of mooring system with body motion. Environmental conditions under consideration are individual cases of wind, waves and current for both operational and extreme sea states (hurricane conditions). This work shows selected results, from which we can make assessment for feasibility of the proposed design of the FPSO with the given conditions.
A Study on Towing Characteristics of a Transportation Barge in Waves
Hong, Sa Young (KIOST) | Nam, Bo Woo (KIOST) | Kim, Jin Ha (KIOST) | Park, Ji-Yong (KIOST)
ABSTRACT This paper presents an experimental and numerical study on towing characteristics of a transportation barge in waves. A series of model tests were carried out at the Ocean Engineering Basin of MOERI/KIOST for measurements of hull forces and motion of a towed transportation barge model in calm water and in waves. Two numerical simulations based on MMG model and cross-flow model were conducted with hydrodynamic derivatives extracted from the model tests. Measured towing trajectories and towline tensions were compared with numerical simulations. Good agreements were obtained between model tests and the numerical results by two different simulation models. Discussions were made on the scale effect on towing characteristics of a barge and wave effect.
ABSTRACT The sloshing effect on the 2D motion of two rectangular cylinders is investigated experimentally. First, experiments for the sway and roll motions of one floater are carried out in a 2D wave flume. Sway and roll motions are allowed, while the heave motion is restricted by the heavy cartridge. The soft spring system is installed besides models in order to prevent the drift-off of models. Then model tests for two floaters of the same configuration are performed. Two floaters are connected by a rigid bar with a gap of a quarter of the model's width. Each floater contains water of a specific filling in order to represent sloshing flow. The correlation between the sway and the roll under the influence of internal flow, the motion characteristics of side-by-side connected rectangular floaters, and the viscous damping effect are analyzed systematically.
- Research Report > New Finding (0.51)
- Research Report > Experimental Study (0.40)
The main problem of this Capacity plan plays an important role for both master production layout is allocation of the required workload to factory and shops and schedule and facility design in shipbuilding. This paper discusses the therefore variation of workload and needed time for mixed products. DEVS for a shipbuilding simulation required by capacity plan. A Therefore, workload expectation in a shipbuilding activity is defined as stochastic shipyard simulation is introduced to evaluate the capability decision making about the planning of equipment, machinery and of executing master production schedules in a shipyard as it simulates processes as well as the production plan in order to fulfill the IHOP and master production schedule. The use of PPR-S model and designated production of vessels. Small changes both in designation of object oriented DEVS as an integration mechanism for simulation is the production shops and assignment of routing can have a great impact also discussed. DEVS shows production problems such as capacity on the workload of production shops and their efficiency.
- North America > United States (0.47)
- South America > Peru (0.28)
- Asia > South Korea (0.28)
- Shipbuilding (1.00)
- Transportation > Marine (0.90)
- Transportation > Infrastructure & Services (0.90)
- Materials > Metals & Mining > Steel (0.68)