Journal of the Korea Academia Industrial Cooperation Society, 2020
In offshore structures, the mean viscous drift force due to drag is considered to be a design par... more In offshore structures, the mean viscous drift force due to drag is considered to be a design part that has not been considered until recently. In particular, it is most important to calculate the drift force acting on a vertical cylinder considering both waves and currents in the low frequency region. This paper presents a process for deriving analytical solutions for the drift forces acting on a fixed vertical cylinder considering waves and currents. The area of the cylinder was considered by dividing it into a splash zone above the free surface and a submerged zone below the free surface. The presence of waves is considered only in the Splash Zone, and in the case of waves and currents, the equations were obtained for both the splash and submerged zones. The results show that drift forces occur due to the significant viscous effects in both the splash zone and the submerged zone. Therefore, the analytical solutions derived in this study can be used to calculate the drift force using the given design variables and form a theoretical basis for judging whether the magnitude of the drift force in each case has a dominant influence within a specific physical range.
EVS 28 KINTEX , Korea , May 3-6 , 2015 Design optimization of lithium-ion battery using hybrid electric vehicle simulation model
As electric vehicle (EV) and hybrid electric vehicle (HEV) have being developed, the importance o... more As electric vehicle (EV) and hybrid electric vehicle (HEV) have being developed, the importance of research and development of lithium-ion battery is on the rise in automobile industry. However, the design method for lithium-ion battery using physical experiment requires expensive cost and much time. Therefore, computational simulation of the battery was introduced to reduce the cost and development-time. In this paper, optimum design of battery is suggested by using optimization techniques and HEV lithium-ion simulation. We carry out analysis of variance to select the important parameters as design variables. By using these design variables, we build kriging surrogate model for total energy of the battery and define the optimization problem. Finally, we perform the optimization to obtain the maximum energy of lithium-ion battery with mass constraint.
The Korea Academia-Industrial cooperation Society, 2020
The interest in renewable energy is increasing due to the depletion of fossil fuels. In particula... more The interest in renewable energy is increasing due to the depletion of fossil fuels. In particular, active research on wave power, which is highly predictable and abundant, is being conducted. The coaxial accelerator-type wave power generator used in this study was designed to improve the power generation efficiency by converting bidirectional linear motion into a rotational force. In an offshore engineering basin, waves were generated, and case tests were performed according to the wave period and wave height. The experimental results were verified by the theoretical method related to the frequency response, and the overall trend was confirmed to be consistent. These results are expected to be useful in estimating the power of wave generators and designing parameters to improve the efficiency of wave energy in the design stage before manufacturing. In addition, the manufacturer can predict the wave energy efficiency of wave generators, which can reduce the development time and cost...
Journal of the Korea Academia Industrial Cooperation Society, 2020
In offshore structures, the mean viscous drift force due to drag is considered to be a design par... more In offshore structures, the mean viscous drift force due to drag is considered to be a design part that has not been considered until recently. In particular, it is most important to calculate the drift force acting on a vertical cylinder considering both waves and currents in the low frequency region. This paper presents a process for deriving analytical solutions for the drift forces acting on a fixed vertical cylinder considering waves and currents. The area of the cylinder was considered by dividing it into a splash zone above the free surface and a submerged zone below the free surface. The presence of waves is considered only in the Splash Zone, and in the case of waves and currents, the equations were obtained for both the splash and submerged zones. The results show that drift forces occur due to the significant viscous effects in both the splash zone and the submerged zone. Therefore, the analytical solutions derived in this study can be used to calculate the drift force us...
Journal of the Korea Academia Industrial Cooperation Society, 2020
In offshore structures, the mean viscous drift force due to drag is considered to be a design par... more In offshore structures, the mean viscous drift force due to drag is considered to be a design part that has not been considered until recently. In particular, it is most important to calculate the drift force acting on a vertical cylinder considering both waves and currents in the low frequency region. This paper presents a process for deriving analytical solutions for the drift forces acting on a fixed vertical cylinder considering waves and currents. The area of the cylinder was considered by dividing it into a splash zone above the free surface and a submerged zone below the free surface. The presence of waves is considered only in the Splash Zone, and in the case of waves and currents, the equations were obtained for both the splash and submerged zones. The results show that drift forces occur due to the significant viscous effects in both the splash zone and the submerged zone. Therefore, the analytical solutions derived in this study can be used to calculate the drift force using the given design variables and form a theoretical basis for judging whether the magnitude of the drift force in each case has a dominant influence within a specific physical range.
EVS 28 KINTEX , Korea , May 3-6 , 2015 Design optimization of lithium-ion battery using hybrid electric vehicle simulation model
As electric vehicle (EV) and hybrid electric vehicle (HEV) have being developed, the importance o... more As electric vehicle (EV) and hybrid electric vehicle (HEV) have being developed, the importance of research and development of lithium-ion battery is on the rise in automobile industry. However, the design method for lithium-ion battery using physical experiment requires expensive cost and much time. Therefore, computational simulation of the battery was introduced to reduce the cost and development-time. In this paper, optimum design of battery is suggested by using optimization techniques and HEV lithium-ion simulation. We carry out analysis of variance to select the important parameters as design variables. By using these design variables, we build kriging surrogate model for total energy of the battery and define the optimization problem. Finally, we perform the optimization to obtain the maximum energy of lithium-ion battery with mass constraint.
The Korea Academia-Industrial cooperation Society, 2020
The interest in renewable energy is increasing due to the depletion of fossil fuels. In particula... more The interest in renewable energy is increasing due to the depletion of fossil fuels. In particular, active research on wave power, which is highly predictable and abundant, is being conducted. The coaxial accelerator-type wave power generator used in this study was designed to improve the power generation efficiency by converting bidirectional linear motion into a rotational force. In an offshore engineering basin, waves were generated, and case tests were performed according to the wave period and wave height. The experimental results were verified by the theoretical method related to the frequency response, and the overall trend was confirmed to be consistent. These results are expected to be useful in estimating the power of wave generators and designing parameters to improve the efficiency of wave energy in the design stage before manufacturing. In addition, the manufacturer can predict the wave energy efficiency of wave generators, which can reduce the development time and cost...
Journal of the Korea Academia Industrial Cooperation Society, 2020
In offshore structures, the mean viscous drift force due to drag is considered to be a design par... more In offshore structures, the mean viscous drift force due to drag is considered to be a design part that has not been considered until recently. In particular, it is most important to calculate the drift force acting on a vertical cylinder considering both waves and currents in the low frequency region. This paper presents a process for deriving analytical solutions for the drift forces acting on a fixed vertical cylinder considering waves and currents. The area of the cylinder was considered by dividing it into a splash zone above the free surface and a submerged zone below the free surface. The presence of waves is considered only in the Splash Zone, and in the case of waves and currents, the equations were obtained for both the splash and submerged zones. The results show that drift forces occur due to the significant viscous effects in both the splash zone and the submerged zone. Therefore, the analytical solutions derived in this study can be used to calculate the drift force us...
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Papers by Yuncheol Kim