• Journal of computational fluids engineering
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• v.5 no.3
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• pp.16-22
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• 2000

In the present study a method of computing fluid-structure interaction is presented to simulate the deformation shape of an oil fence which is used to contain or to divert the split oil in sea water. The computation is performed by taking into account of the force and moment balance in each computational element of the oil fence. The forces and moments acting on each element of the structure is computed from the flow analysis, which in turn is used to predict deformed shape of the structure until the procedure converges. The flexibility of the oil fence was also considered in the analysis. It is shown from the present study that the predicted deformed shapes agree quite well with the available experiment data.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.2
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• pp.75-82
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• 2017

With the development of computational fluid dynamics (CFD), studies on shipbuilding and maritime issues including free-surface wave flow have been conducted. Although the volume of fluid (VOF) and level-set methods are widely used to study the free-surface wave flow, disadvantages exist. In particular, it takes a long time to obtain solutions. In this study, a free-surface capturing code is developed for ship and offshore structures. The developed code focuses on accuracy and computation time. Open source CFD libraries, termed OpenFOAM, are used to develop the code. The results obtained using the developed code are compared with those obtained using interFoam. The results show that the developed code could be used to capture the free-surface wave flow without numerical diffusion; moreover, the accuracy of the developed code is largely the same as that of interFoam.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1838-1845
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• 2011

This paper deals with coupled electromagnetic-thermal field analysis for thermal fluid analysis of oil immersed power transformer. Electric power losses are calculated from electromagnetic field analysis and are used as input source of thermal field analysis based on computational fluid dynamics(CFD). Particularly, In order to accurately predict the temperature rise in oil immersed power transformer, the thermal problem should be coupled with the electromagnetic problem. Moreover, to reduce analysis region, the heat transfer coefficient is applied to boundary surface of the power transformer model. The coupling method results are compared with the experimental values for verifying the validity of the analysis. The predicted temperature rises show good agreements with the experimental values.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.575-578
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• 2006

In designing smoke-control system of rescue station in train tunnel, a purpose is to prevent a disaster by proposing the jet fan operation together with smoke-control curtain in tunnel fire. This study has investigated the relationship of the Heat Release Rate(HRR) and a adequate ventilation velocity to control the fire propagation in tunnel fire, and has improved the effect of the smoke-control curtain on preventing the flow of pollutants. In this study, Computational Fluid Dynamics(CFD) simulations with ST AR-CD(ver 3.24) were carried out on predicting the fire spreading and the flow of pollutants, considering jet fan operations and effect of smoke-control curtain. Our simulation domain is the full scale model of the 'DAEGWALLYEONG' 1st tunnel. The results represent that ventilation operation can control the fire spreading and pollutants effectively to prevent a disaster.

• Advances in aircraft and spacecraft science
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• v.2 no.2
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• pp.109-124
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• 2015

This paper deals with the aerodynamic and aerothermodynamic trade-off analysis of a hypersonic flying test bed. Such vehicle will have to be launched with an expendable launcher and shall re-enter the Earth atmosphere allowing to perform several experiments on critical re-entry phenomena. The demonstrator under study is a re-entry space glider characterized by a relatively simple vehicle architecture able to validate hypersonic aerothermodynamic design database and passenger experiments, including thermal shield and hot structures. A summary review of the aerodynamic characteristics of two flying test bed concepts, compliant with a phase-A design level, has been provided hereinafter. Several design results, based both on engineering approach and computational fluid dynamics, are reported and discussed in the paper.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.2
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• pp.144-153
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• 2009

It is widely known that no-slip assumptions are often violated on regular basis in micrometer- or nanometer-scale fluid flow. In the case of cavity-filling process of nanoimprint lithography(NIL), slip phenomena take place naturally at the solid-to-liquid boundaries, that is, at the mold-to-polymer or polymer-to-substrate boundaries. If the slip or partial slip phenomena are promoted at the boundaries, the processing time of NIL, especially of thermal-NIL which consumes more tact time than that of UV-NIL, can be significantly improved. In this paper it is aimed to elucidate how the cavity-filling process of NIL can be influenced by the slip phenomena at boundaries and to what degree those phenomena increase the process rate. To do so, computational fluid dynamics(CFD) analysis of cavity filling process has been carried out. Also, the effect of mold pattern shape and initial thickness of polymer resist were considered in the analysis, as well.

• Particle and aerosol research
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• v.10 no.4
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• pp.155-162
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• 2014

The internal temperature will change depending on operation conditions and material of cyclone dust collector. This study compares the results of collection efficiency and temperature distribution on the different heat flux at wall of dust collector. The previous researcher's experiment results were used to confirm the reliability of CFD(Computational Fluid Dynamics) model. Based on this verified CFD model, we extended the analysis on the cyclone dust collectors. In CFD study, we used RNG k-epsilon model for analysis of turbulence flow, fluid is air, the velocity at inlet is 10 m/s, the temperature of air is $600^{\circ}C$. Because of the difference of outer vortex and inner vortex temperature, the collection efficiency will reduce with the increase of heat flux, showed the highest collection efficiency at heat insulation.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1675-1677
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• 2005

In case of attaching thermoelectric module and heat source, the polymer sheet is attached on the $AL_{2}O_3$ plate, which Is cold and hot side of thermoelectric module, in order to enhance mechanical safty of the system. It is impossible to calculate the exact distribution of temperature and flow pattern of inner gap of thermoelectric module. Therefore CFD(Computational Fluid Dynamics) analysis was executed to determine the thermo-fluid phenomena and distribution by Fluent. As the result of these analysis, heat transfer was dominated by conduction and the difference of temperature was linear distribution according to the thickness of polymer sheet.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.976-981
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• 2006

In case of attaching thermoelectric module and heat source, the polymer pad is attached on the $Al_2O_3$ plate, which is cooling side of thermoelectric module, in order to enhance mechanical safety of the system. It is impossible to calculate the exact distribution of temperature and flow pattern of inner gap of thermoelectric module. Therefore CFD(Computational Fluid Dynamics) analysis was executed to determine the thermo-fluid phenomena and distribution by Fluent. As the result of these analysis, heat transfer was dominated by conduction and the difference of temperature was linear distribution according to the thickness of polymer sheet.

• Journal of Ocean Engineering and Technology
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• v.36 no.4
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• pp.280-294
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• 2022

This study reviews the recent development and research results of a fixed oscillating water column (OWC) wave energy converter (WEC). The OWC WEC can be divided into fixed and floating types based on the installation location and movement of the structure. In this article, the study on a stationary OWC WEC, which is close to commercialization through the accumulation of long-term research achievements, is divided into five research categories with a focus on primary energy conversion research. These research categories include potential-flow-based numerical analysis, wave tank experiments, computational fluid dynamics analyses toward investigation of fluid viscous effects, U-shaped OWC studies that can amplify water surface displacement in the OWC chamber, and studies on OWC prototypes that have been installed and operated in real sea environments. This review will provide an overview of recent research on the stationary OWC WEC and basic information for further detailed studies on the OWC.