• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.107-116
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• 1990

The liquid sloshing in an elastic tank is a fluid-structure interaction problem. It requires nonlinear analysis to solve the complicated physics involved in the large interaction of fluid-structure, the variation of dynamic characteristics of structure due to hydrodynamic loading, and the distorsion of fluid flow due to structural vibration. In this paper a Lagrangian FEM is introduced to analyze the liquid sloshing in an elastic tank assuming that the elastic wall is one degree of freedom rigid wall. Numerical integration is performed using an implicit-explicit algorithm, which is formed by mixing the predictor-corrector method and the Runge-Kutta 4th order method. The influence of dynamic characteristics of the sloshing tank on the fluid flow is discussed. The numerical method is also applied for the simulation of the wall generated wave in the tank.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.752-762
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• 2021

The Smoothed Particle Hydrodynamics is one of the most widely used mesh-free numerical method for thermo-fluid dynamics. Due to its Lagrangian nature and simplicity, it is recently gaining popularity in simulating complex physics with large deformations. In this study, the 3D single/two-phase numerical simulations are performed on the Liquid Metal Reactor (LMR) centralized sloshing benchmark experiment using the SPH parallelized using a GPU. In order to capture multi-phase flows with a large density ratio more effectively, the original SPH density and continuity equations are re-formulated in terms of the normalized-density. Based upon this approach, maximum sloshing height and arrival time in various experimental cases are calculated by using both single-phase and multi-phase SPH framework and the results are compared with the benchmark results. Overall, the results of SPH simulations show excellent agreement with all the benchmark experiments both in qualitative and quantitative manners. According to the sensitivity study of the particle-size, the prediction accuracy is gradually increasing with decreasing the particle-size leading to a higher resolution. In addition, it is found that the multi-phase SPH model considering both liquid and air provides a better prediction on the experimental results and the reality.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.215-222
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• 2009

In the present study, a numerical analysis on the sloshing in a tank with the harmonic motion was investigated. A VOF method was used for two-phase flows inside the sloshing tank and a source term of the momentum equation was applied for the harmonic motion. This numerical method was verified by comparing its results with the available experimental data. The sloshing in a tank causes the instability of the fluid flows and the fluctuation of the impact pressure on the tank. By these phenomena of the tank sloshing, the sloshing problems such as the failure and the noise of system can be generated. For the reduction of these sloshing problems, the various baffles such as the horizontal/vertical plate baffles and the porous baffles inside the tank are installed. With the installations of these baffles, the characteristics of the liquid behavior in the sloshing tank, the impact pressure on the wall, the amplitude of the free surface near the wall and the sloshing noise were numerically analyzed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2039-2046
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• 2003

Storage tank filled with fluid has unique dynamic characteristics compared to general structures, due to the interaction between fluid and structure. The oscillation of the fluid surface caused by external forces is called sloshing, which occurs in moving vehicles with contained liquid masses, such as trucks, railroad cars, aircrafts, and liquid missles. In this study, the evaluation method for the reduction of sloshing, the optimized size and location of wing and diaphragm baffles are suggested based on the experimental results. The experimental device can simulate the translation motion. A rectangular tank and various baffles are fabricated to study on the sloshing characteristics. The forces measured using the load cell at tank wall and those are compared with each other through the Fourier transformation for various conditions. The study of the sloshing of the rectangular tank equipped with baffles is conducted under the same conditions with non-baffled rectangular tank experiment. From the experimental results, the sloshing reduction effect by the baffles is observed. In conclusion in case of diaphragm baffles, the optimized size ratio of the width of baffle to the water height is 0.44 and the installation location has no effect to the damping of sloshing. In case of wing baffles, the optimized size ratio of the width of baffle to the length of a rectangular tank is 0.1 and the optimized location ratio of the baffle to the water height is 0.9.

• Earthquakes and Structures
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• v.13 no.1
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• pp.67-77
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• 2017

Oil storage tanks are vital life-line structures, suffered significant damages during past earthquakes. In this study, a numerical model for an unanchored vertical vaulted-type tank was established by ANSYS software, including the tank-liquid coupling, nonlinear uplift and slip effect between the tank bottom and foundation. Four actual earthquakes recorded at different soil sites were selected as input to study the dynamic characteristics of the tank by nonlinear time-history dynamic analysis, including the elephant-foot buckling, the liquid sloshing, the uplift and slip at the bottom. The results demonstrate that, obvious elephant-foot deformation and buckling failure occurred near the bottom of the tank wall under the seismic input of Class-I and Class-IV sites. The local buckling failure appeared at the location close to the elephant-foot because the axial compressive stress exceeded the allowable critical stress. Under the seismic input of Class-IV site, significant nonlinear uplift and slip occurred at the tank bottom. Large amplitude vertical sloshing with a long period occurred on the free surface of the liquid under the seismic wave record at Class-III site. The seismic properties of the storage tank were affected by site class and should be considered in the seismic design of large tanks. Effective measures should be taken to reduce the seismic response of storage tanks, and ensure the safety of tanks.

• Journal of Ocean Engineering and Technology
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• v.29 no.4
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• pp.291-299
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• 2015

A variety of inner baffles are often installed to reduce liquid sloshing and prevent tank damage. In particular, a porous baffle has a distinct advantage in reducing sloshing by changing the natural periods and dissipating the wave energy in a tank. In model tests, porous baffles with five different porosities were installed vertically in a liquid tank under sway motion. The free surface elevations and pressures were measured using an image processing technique and a pressure gage for various combinations of baffle's porosity and submergence depth, and tank's amplitude and period. The experimental results were in good agreement with the analytic solutions (Cho, 2015), with the exception of a quantitative difference at resonant periods. The experimental results showed that the sloshing characteristics in a tank were closely dependent on both the porosity and submergence depth of the baffle, and the optimal porosity existed near P = 0.1275.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.04a
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• pp.157-164
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• 1996

Analyses of linear sloshing modes and seismic responses for cylindrical vessel containing fluid are performed by general finite element computer program, ANSYS. In order to examine the effectiveness of the sloshing analysis procedure, the calculated results are compared with experimental ones in the literature. Liquid sloshing effects in cylindrical LNG vessel are analyzed and the fluid-structure interaction effects are evaluated under the seismic loads. The sloshing frequencies calculated agree well with experimental results. The forces and moments for fixed and isolated LNG vessel are also calculated to evaluate the sloshing effects.

• Journal of the Korean Society of Safety
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• v.18 no.1
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• pp.101-107
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• 2003

Dynamic behavior of flexible rectangular liquid storage structures is analysed by the developed method. The rectangular liquid storage structures are assumed to be fixed to the ground and a moving coordinate system is used. The irrotational motion of invicid and incompressible ideal fluid is represented by two analytic solutions. One is the solution of the fluid motion in the rigid rectangular liquid storage structure due to ground motions and the other is the solution of the fluid motion by the motion of the wall in the flexible rectangular liquid storage structure. The motion of structure is modeled by finite elements. The fluid-structure interaction effect is reflected into the coupled equation of motion as added fluid mass matrix. The free surface sloshing motion and hydrodynamic pressure acting on the wall in the flexible rectangular liquid storage structure due to the horizontal ground motion are obtained by the developed method and verified.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.947-955
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• 2020

Predicting the sloshing motion of a coolant during a seismic assessment of a rectangular spent fuel pool is of critical concern. Linear theory, which provides a simple analytical method, has been used to predict the sloshing motion in rectangular pools and tanks. However, this theory is not suitable for the high-frequency excitation problem. In this study, the authors developed a simple analytical method for predicting the sloshing motion in a rectangular pool for a wide range of excitation frequencies. The correlation among the linear theory parameters, influencing on excitation and convective waves, and the excitation frequency is investigated. Sloshing waves in a rectangular pool with several liquid heights are predicted using the original linear theory, a modified linear theory and computational fluid dynamics analysis. The results demonstrate that the developed method can predict sloshing motion over a wide range of excitation frequencies. However, the developed method has the limitations of linear solutions since it neglects the nonlinear features of sloshing motion. Despite these limitations, the authors believe that the developed method can be useful as a simple analytical method for predicting the sloshing motion in a rectangular pool under various external excitations.

• Journal of Ocean Engineering and Technology
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• v.2 no.1
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• pp.78-82
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• 1988

자유표면 유동을 시뮬레이션할 수 있는 수치 알고리듬 중 가장 최근에 개발된 volume of fluid (VOF) 방법을 이용하여 뚜껑이 닫힌 사각 컨테이너 속의 슬라싱을 시뮬레이션 하였다. 그 결과 유동이 작은 경우에는 알고리듬이 불안정하게 되어 장기간 시뮬레이션을 어렵게 하는 문제점이 발견되었다. 이 문제점을 해결하기 위해 VOF 알고리듬이 불안정하게 되어 장기간 시뮬레이션을 어렵게하는 문제점이 발견되었다. 이 문제점을 해결하기 위해 VOF 알고리듬 중 유량이동 알고리듬을 수정하여 원래의 알고리듬으로 시뮬레이션한 결과와 비교 분석하였다