• 산업기술연구
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• 제29권B호
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• pp.65-72
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• 2009

In this paper centrifuge model tests and numerical analysis on the coastal structure on the marine deposits of sand were performed to investigate the behavior of structure and foundation under the condition of wave action in field. In centrifuge model experiments, construction sequence of coastal structure such as preparation of sand deposit, excavation replacement, rubble mound with crushed stones and installment of coastal structure was reconstructed and the behavior of ground settlement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of coastal structure due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge mode experiments with respect to the behavior of structure as well as ground.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.553-556
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• 2002

A numerical study on the use of the momentum interpolation mettled for flows with a large body force is presented. The inherent problems of the momentum interpolation method are discussed first. Numerical experiments are performed for a typical flow involving a large body force. The tact that the momentum interpolation method may result in physically unrealistic solutions is demonstrated. Numerical experiments changing the numerical grid have shown that a simple way of removing the physically unrealistic solution is a proper grid refinement where there is a large pressure gradient. An effective way of specifying the pressure and pressure correction at the boundary by a local mass conservation near the boundary is proposed, and it is shown that this method can effectively remove the inherent problem of the specification of pressure and pressure correction at the boundary when one uses the momentum interpolation method.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.15-18
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• 1995

Three-dimensional steady and pulsatile flow experiments and numerical simulations have conducted to investigate the flow characteristics in the aortic bifurcation model. In vitro velocity measurements were made using both laser Doppler anemometry and pulsed Doppler ultrasound velocimetry. In this study, flow phenomena in the aortic bifurcation model are discussed extensively and the numerical results are compared with experimental results.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.256-266
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• 2012

Cavitating flow simulation is of practical importance for many engineering systems, such as marine propellers, pump impellers, nozzles, torpedoes, etc. The present work has developed the base code to solve the cavitating flows past the axisymmetric bodies with several forebody shapes. The governing equation is the Navier-Stokes equation based on homogeneous mixture model. The momentum is in the mixture phase while the continuity equation is solved in liquid and vapor phase, separately. The solver employs an implicit preconditioning algorithm in curvilinear coordinates. The computations have been carried out for the cylinders with hemispherical, 1-caliber, and 0-caliber forebody and, then, compared with experiments and other numerical results. Fairly good agreements with experiments and numerical results have been achieved. It has been concluded that the present numerical code has successfully accounted for the cavitating flows past axisymmetric bodies. The present code has also shown the capability to simulate ventilated cavitation.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.101-110
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• 2005

In this paper, the experiments have been conducted to measure the residual velocity for 3.5g steel ball perforating light weight metal plates of aluminum alloy and magnesium alloy. Non-contact electro-magnetic sensors were used to measure the velocity of steel ball before/after perforating plates. The thicknesses of specimens used were about 2.8mm and 4.8mm. The impact velocities of steel ball were from 662m/s to 3594m/s. With same conditions, numerical analysis using Autodyn 2D has been conducted. The results of numerical analysis corresponded with those of experiments. Also, It is suggested that the difference between the residual velocity of experiment or numerical analysis and that of THOR experimental equation of BRL grew smaller as the impact velocity were increased.

• 충청수학회지
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• 제7권1호
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• pp.97-107
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• 1994

This paper proposes a numerical method approximating the least squares solution of minimum norm (LSSMN) to the first kind integral equation Kf=g with a special kernel, and then some numerical experiments for this method are provided.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.365.2-365
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• 2002

The flow field around a symmetrical airfoil in a uniform flow under the generation of noise was studied by experiments and numerical simulation. The experiments are conducted by visualizing the surface flow over the airfoil with a shear-sensitive liquid-crystal coating and by measuring the instantaneous velocity field around the trailing edge of the airfoil. The numerical simulation was carried out by LES. (omitted)

• 한국수소및신에너지학회논문집
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• 제29권2호
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• pp.155-162
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• 2018

In this paper, the reliability of the numerical analysis using the two phase flow on the behavior of the hydrogen bubbles in the alkali electrolysis stacks was investigated by comparing the results obtained from numerical analysis and flow visualization experiments. As the results, through comparison with results gotten to visualization experiments, it is possible to approximate analysis for the flow of hydrogen bubbles in the stacks by numerical analysis using the two-phase flow. Also, the flow of hydrogen bubbles around the electrodes could be similarly analyzed by numerical analysis using the two-phase flow.

• 한국도로학회논문집
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• 제18권1호
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• pp.73-83
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• 2016

PURPOSES : The purpose of this study is to develop a method for improving the accuracy of analysis results obtained from a two-dimensional (2-D) numerical analysis model of continuously reinforced concrete pavement (CRCP). METHODS : The analysis results from the 2-D numerical model of CRCP are compared with those from more rigorous three-dimensional (3-D) models of CRCP, and the relationships between the results are recognized. In addition, the numerical analysis results are compared with the results obtained from field experiments. By performing these comparisons, the calibration factors used for the 2-D CRCP model are determined. RESULTS : The results from the comparisons between 2-D and 3-D CRCP analyses show that with the 2-D CRCP model, concrete stresses can be overestimated significantly, and crack widths can either be underestimated or overestimated by a slight margin depending on the assumption of plane stress or plane strain. The behaviors of crack width in field measurements are comparable to those obtained from the numerical model of CRCP. CONCLUSIONS : The accuracy of analysis results from the 2-D CRCP model can be improved significantly by applying calibration factors obtained from comparisons with 3-D analyses and field experiments.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.309-314
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• 1999

In this paper, an application of finite element procedure fur tunnel failure analysis has been studied. The numerical model is applied to the simulation of a series of plane strain laboratory tests on the small scale model of a shallow tunnel. By comparing experimental and numerical results some conclusions are drawn on the effectiveness of the numerical approach. The findings from these numerical experiments show relative differences in the pattern of failure behaviour for shallow tunnels.