• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.117-122
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• 2019

In the field of fluid dynamics, the sloshing effects are most common and significant problem. It is usually appeared in the tank filled with fluid which is on the main structure, thus, sloshing effects and its impact load may affect to entire system. For the sloshing effects analysis, impact loads due to tank motion is generally investigated theocratically, experimentally and numerically. The difficulty of sloshing phenomenon is non-linearity induced by large deformation at the free-surface. In this regard, it is well known issue that the repeatability on the sloshing problems is very low. In this study, moving particle semi-implicit method was employed to simulate sloshing problem and then the results were compared with corresponding experiments captured by high accuracy high speed camera. The results from numerical simulation was compared to experimental results.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1601-1606
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• 2004

In this paper, the unsteady behavior of the viscous flow field past an impulsively started elliptic cylinder is studied numerically. In order to analyze flow field, we introduce vortex particle method. The vorticity transport equation is solved by fractional step algorithm which splits into convection term and diffusion term. The convection term is calculated with Biot-Savart law, the no-through boundary condition is employed on solid boundaries. The diffusion term is modified based on the scheme of particle strength exchange. The particle redistributed scheme for general geometry is adapted. The flows around an elliptic cylinder are investigated for various attack angles at Reynolds number 200. The comparison between numerical results of present study and experimental data shows good agreements.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.7
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• pp.809-817
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• 2004

In this paper, the unsteady behavior of the viscous flow field past an impulsively started elliptic cylinder is studied numerically. In order to analyze flow field, we introduce vortex particle method. The vorticity transport equation is solved by fractional step algorithm which splits into convection term and diffusion term. The convection term is calculated with Biot-Savart law, the no-through boundary condition is employed on solid boundaries. The diffusion term is modified based on the scheme of particle strength exchange. The particle redistributed scheme for general geometry is adapted. The flows around an elliptic cylinder are investigated for various attack angles at Reynolds number 200. The comparison between numerical results of present study and experimental data shows good agreements.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.73-81
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• 2019

Numerical simulations are performed for the thermal fluid flow around a circular cylinder, and the particle trajectories are calculated to investigate the particle motions and deposition characteristics. We aim to understand the effects of three important parameters (particle Stokes number, temperature difference in the flow and on the cylinder surface, and thermal conductivity ratio between the fluid and the particles) on the deposition efficiency. The results show that the thermophorectic effect is insignificant for particles with large Stokes numbers, but it affects particles with small Stokes numbers. The deposition efficiency increases with the increase in temperature difference between the flow and the cylinder or the decrease in ratio of thermal conductivity of the particles to the fluid. When thermophoresis becomes significant, the particles are deposited even on the back side of the cylinder.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.53-58
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• 2006

Along with the development of costal engineering, various type of breakwaters have been built. The main purpose of breakwaters are to provide harbour protection against waves, to stabilize beaches against erosion due to large wave action, and to provide for temporary wave protection for installation on or under water surface. This paper an application example of PIV system for analyzing the flow of Floating Breakwater with double barriers. We introduce an analysis method to predict the characteristics of flow around the neighboring fields of Floating Breakwater with double barriers in order to develop a high performance model. Flow visualization has conducted in circulating water channel by a high speed camera and etc. Flowing phenomenon according to velocity distribution and flow separation around the breakwater with double barriers were obtained by 2-D PIV system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.2
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• pp.70-77
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• 1999

The disturbance of oil-water interface confined between tandem fences caused by a sequence of traveling vortices below the interface is investigated. The traveling vortices are assumed to be those detached from the tip of the fore fence. The potential flow is assumed and the density interface is replaced as a sheet of vortex. The shape of the interface is predicted by tracing a finite number of marker particles placed at the interface. The velocity of the marker particles is determined by the Biot-Savart integral along the vortex sheet plus the contribution from the traveling point vortices. The rate of change of vortex-sheet strength is predicted by using an evolution equation for vorticity. The calculated results obtained for various conditions demonstrate that the large amplitude of interfacial wave following the moving vortek can be generated by the vortices.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.377-382
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• 2010

The Present study uses non-Newtonian simulant gel propellant mixed by Water, Carbopol 941, and NaOH solution in order to analyze the gel propellant flow behavior. Rheological data have been measured and obtained prior to the analysis of flow characteristics where water-gel propellant as well as water-gel propellant with $Al_2O_3$ nano particles are both used. The critical Dean number were examined by numerical simulation of gel propellant in the U-shape duct flow. It is found that though gel-nano propellants have higher apparent viscosity, the critical Dean number did not showed notable difference with respect to the water-gel propellant. It is believe that this is due to the fact that the power law index of both propellants have close value, as was demonstrated by Fellouah et al.[1]

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.161-168
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• 2007

In this paper, the floating body with double barriers is introduced with a study on the flow patterns and characteristics in around the floating body by using 2 frame p article tracking method. This paper introduce an analisys method to predict the characteristics of flow around the neighbording fields of Floating Body with double barriers in order to investigate a high performance model. Flow visualization has conducted in a circulating water channel by a high speed camera and etc. Flow phenomena according to velocity distribution and flow separation around the floating body with double barriers were obtained by two-dimensional PIV system.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.9-18
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• 2016

In this research, the modeling of erosive burning and analysis of effective parameters were carried out for the application of fluid-structure integration analysis. The manufacture, test, and analysis of erosive burning motors were carried out to estimate the erosive burning applying Lenoir & Robillard model considering effective parameters. The erosive burning phenomenon was detected from experimental results. Erosive burning model and its effective parameters were evaluated and analyzed considering existence of aluminum in propellant, relationship among erosive burning coefficients according to characteristic length, effect of grain initial temperature. The erosive burning model was applied to the fluid-structure integration analysis, and the estimated results were close to the experimental results.

• Fire Science and Engineering
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• v.31 no.4
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• pp.7-11
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• 2017

The use of special gas masks such as PAPR is strongly required for the safe and efficient work of fire-fighters in removing fire residue and rescue activity. Special gas masks commonly use canisters with carbon activated particles. This paper analyzed the pressure distribution, velocity distribution and pressure loss characteristics in canisters using CFD simulation, and showed pressure drops are affected by inlet air velocity, canister geometry and increase dramatically especially with the decrease of particle diameters and volume fractions.