• 한국소음진동공학회논문집
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• 제13권10호
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• pp.791-797
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• 2003

A liquid storage rectangular tank structures are used In many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks In contact with Inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine or propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. In the previous report, we have developed numerical tool of vibration analysis of 3-dimensional tank structure using finite elements for plates and boundary elements for fluid region. In the present report, using the numerical analysis, vibrations characteristics In deep water tank are investigated and discussed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1079-1084
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• 2003

A liquid storage rectangular tank structures are used in many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks in contact with inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks ill contact with fluid near engine or propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. In the previous report, we have developed numerical tool of vibration analysis of 3-dimensional tank structure using finite elements for plates and boundary elements for fluid region. In the present report, using the numerical analysis, vibrations characteristics in deep water tank are investigated and discussed.

• Geomechanics and Engineering
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• 제5권2호
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• pp.165-185
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• 2013

In the present study, the numerical and experimental investigations were performed on the backfill- exterior wall-fluid interaction systems in case of empty and full tanks. For this, firstly, the non-linear three dimensional (3D) finite element models were developed considering both backfill-wall and fluid-wall interactions, and modal analyses for these systems were carried out in order to acquire modal frequencies and mode shapes by means of ANSYS finite element structural analysis program. Secondly, a series of field tests were fulfilled to define their modal characteristics and to compare the results from proposed approximation in the selected structures. Finally, comparing the theoretical predictions from the finite element models to results from experimental measurements, a close agreement was found between theory and experiment. Thus, it can be easily stated that experimental verifications provide strong support for the finite element models and the proposed procedures themselves are the meritorious approximations to the real problem, and this makes the models appealing for use in further investigations.

• 대한기계학회논문집B
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• 제27권8호
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• pp.1142-1149
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• 2003

The present study describes a numerical analysis for simulation of the sloshing of flows with free-surface which contained in a rectangular tank moving in harmonic or pitching motion. The VOF function, representing the volume fraction of a cell occupied by the fluid, is calculated for each cells, which gives the location of the free-surface filling any some fraction of cells with fluid. The time-dependent changes of free-surface height are used for visualization subject to several conditions such as fluid height, horizontal acceleration, sinusoidal motion, and viscosity. The free-surface heights were used for comparing wall-force, which is caused by sloshing of flows. Damping effects by baffles were extensively investigated for various conditions in terms of baffle shape and position.

• 한국가시화정보학회지
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• 제18권3호
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• pp.14-22
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• 2020

An experiment, in the cases that satisfies deep water condition, has been performed to observe the strongly nonlinear sloshing flow in a rectangular tank. A variety of parametric study on oscillating frequency and amplitude was conducted and we found that two types of wave motions, sloshing wave and Faraday wave, could be persisting simultaneously even in horizontal sloshing problem. Moreover, it is observed both of symmetric and skewed symmetric Faraday wave exist. A comprehensive explanation is given to the generation mechanism of those waves and how to interact among them.

• 한국지진공학회논문집
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• 제6권6호
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• pp.55-64
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• 2002

사각형 유체저장 탱크내에 저장되어 있는 유체의 비선형 유동거동을 섭동법을 사용하여 해석하였다. 제시된 방법에 의한 비선형 해석결과는 기존의 연구결과와 잘 일치하였다. 지반특성과 탱크형상에 따른 유체 표면의 비선형 거동 특성을 분석하여 비선형 해석의 중요성을 입증하였다. 유체의 비선형 거동은 토사지반에서 크게 나타나며 특히 Broad Tank에서의 응답은 대단히 크게 나타났다. 일반적으로 유체표면 유동의 비선형 해석결과는 선형해석결과 보다 크게 나타났다. 유체저장탱크의 설계시 선형해석 만으로는 최대응답을 과소평가할 수 있으므로 비선형 해석을 반드시 수행할 필요가 있다.

• 한국전산유체공학회지
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• 제20권1호
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• pp.16-25
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• 2015

The present study investigates the sloshing phenomena in a two-dimensional rectangular tank at a low filling level by using a level set method based on finite volume method. The code validations are performed by comparing between the present results and previous numerical and experimental results, which gives a good agreement. Various excitation frequencies and excitation amplitude of the 30% filling height tank have been considered in order to observe the dependence of the sloshing behavior on the excitation frequency and amplitude. Regardless of excitation amplitude, the maximum value of wall pressure occurs when the excitation frequency reaches the natural frequency. The time sequence of free surface and corresponding streamlines for excitation frequencies have been presented to analysis the variation of wall pressure according to time, which contributes to explain the double peaks in the time variation of wall pressure.

• 한국소음진동공학회논문집
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• 제23권7호
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• pp.662-668
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• 2013

In this paper, possibility of controlling motion of a floating structure using a tuned liquid damper (TLD) is numerically investigated. A TLD is a tank partially filled with liquid. Sloshing motion of liquid inside a tank is known to suppress movement of the tank subject to external excitations at specific frequency. The effects of sloshing phenomena inside a rectangular floating body on its surge motion are investigated by varying external excitation frequency. First, a grid-refinement study is carried out to ensure validity of grid independent numerical solutions using present numerical techniques. Then, surge motion of the floating body subjected to external wave is simulated for five different excitation frequencies of which the center frequency equals to the natural frequency of internal liquid sloshing. The normalized amplitudes of surge motion of the target floating body are compared according to the excitation frequency, for the cases with and without water inside the floating body. It is shown that the motion of the floating body can be minimized by matching the sloshing natural frequency to the excitation frequency.

• 설비공학논문집
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• 제24권7호
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• pp.545-552
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• 2012

The objective of this study is to analyze the effect on the energy consumption of an instant cooling type water purifier by the design parameters of the cooling tank. Initially, the simulation program was developed and verified. The simulation results showed that the energy consumption was reduced by replacing the shape of the cooling tank from a rectangular to a cube, increasing the evaporator length, decreasing the volume of the cooling tank, and increasing the performance of the insulator. The order of the effect magnitude on the energy consumption was as follows; volume of the cooling tank, conductivity and thickness of the insulator, shape of the cooling tank, length of the evaporator, and length of the water tube.

• 한국전산구조공학회논문집
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• 제33권6호
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• pp.383-390
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• 2020

유연한 지반에 놓인 액체저장탱크의 지진 거동은 유체-구조물-지반 상호작용에 의해 복잡하게 나타나므로, 이 시스템의 지진응답과 피해를 정확하게 예측하기 위해서는 이를 엄밀히 고려하여야 한다. 이 연구에서는 유체-구조물-지반 상호작용을 엄밀히 고려하여 유연한 지반에 놓인 직사각형 액체저장탱크의 지진응답 해석을 수행하고 그 응답 특성을 분석하고자 한다. 이를 위해 지진하중 작용 시 발생하는 유체의 동수압력 및 지반과 구조물 간의 상호작용력을 유한요소 기법을 사용하여 산정한다. 이때, 반무한 지반에서의 에너지 방사를 고려하기 위해 mid-point integrated finite element와 점성 감쇠기를 사용하여 지반 원역의 거동을 모사한다. 이와 같이 산정된 동수압력과 지반-구조물 상호작용력을 구조물의 유한요소에 작용시킨다. 자유장 해석을 통하여 입사 지진파에 의한 유효 지진력을 산정한다. 유연한 지반에 놓인 직사각형 액체저장탱크의 지진응답 해석을 통하여 지반-구조물 상호작용의 효과로 인해 시스템 응답의 변화가 다양하게 나타남을 확인할 수 있다. 그러므로, 유연한 지반에 놓인 직사각형 액체저장탱크의 내진설계를 수행하거나 내진성능을 검토할 때는 유체-구조물-지반 상호작용을 엄밀히 고려하여야 할 것이다.