• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5060-5066
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• 2015

The number of shop needed for the fabrication of sphere type LNG tank is proportional to that of the tank radius to be constructed. Due to limitation of facility investment including building sites, it is practically difficult to fabricate various size tanks of perfectly spherical shape in the yards. The efficient method to increase cargo tank capacity is to extend vertically the conventional sphere type LNG tank by inserting a cylindrical shell structure. In this study, equations for static design loads are developed for sphere type LNG tank with central extension. The results of this study will be combined with dynamic design loads to build the simplified analysis method which enable the precise initial estimate instead of time consuming finite element analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.886-891
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• 2001

This paper present the results of finite element analysis to examine the sloshing characteristics of the cylindrical and rectangular tank partially fluid-filled. The sloshing characteristic for the existence and the non-existence of the baffle are investigated and the results compared with the references. For the rectangular tank, the vertical displacements are used to study of the sloshing characteristics. But for the cylindrical tank, the damping factors obtained from the vertical displacements of free surface with the depth of ring baffle are usedto study of the sloshing characteristics. The adaptive meshing method in the ABAQUS 5.8/Explicit is used for the sloshing analysis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.10
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• pp.2647-2656
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• 1995

The present work was performed to axially and radially investigate the local cold storage performance in the cylindrical tank with the spherical capsules inserted n-Tetradecane as a new cold storage material. The local cold storage performance of the capsules in the tank was experimentally investigated for the inlet temperature of -7, -5, -3, 0.deg. C, for the flow rate of 0.95, 1.89, 2.84, 6.00 l/min, and for the diameter ratio of 4.9, 9.0, 13.1. The local cold storage performance in the case of using water applied for the commercial ice-ball system was axially investigated by changing the flow rate only with the inlet temperature of -7.deg. C and the diameter ratio of 9.0 in order to compare with the performance in the case of using n-Tetradecane. For the case of using n-Tetradecane, the difference of cold storage period between the first and the seventh story was increased as the inlet temperature was increased and the flow rate was decreased. The capsules at the center of the tank showed the supercooling and the increased cold storage period compared with the capsules at the wall of the tank due to the small porosity and insufficient cold storage performance at the center of the tank as the diameter ratio is increased. The case using water showed worse cold storage performance due to comparatively large supercooling than the case using n-Tetradecane.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.19-28
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• 1999

While the codifying works or the earthquake resistant design codes for buildings and bridges have been carried out progressively, such works for tank structures are still at the beginning steps. In case of the collapse of tank structures under seismic actions, substantially severe damages are expected due to the spillage of tank contents in addition to the direct economic losses of tanks and contents. Therefore not only the analysis and verification methods for the dynamic behavior of tank structures but also the measures of minimizing the damage propagation should be included in the codes for tank structures. In this paper the design concepts and principles, the analysis and verification methods as well as the measures against the damage propagation are set forth, which are mandatory for the preparation of the earthquake resistant design codes for cylindrical liquid-storage steel tanks.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.10a
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• pp.61-66
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• 1992

The present paper deals with the optimum design of reinforced concrete cylindrical shell tanks in according to ACI 318-89 code. The purpose of this investigation is to find the optimum values of the steel ratio and the effective thickness of reinforced concrete cylindrical shell tanks. The analysts is carried out using a simple computer programming, SMAP(segmented matrix analysis package). The optimization is carried out using GINO programming. Optimum results for cylindrical shell tanks with uniform, stepwise and piecewise linealy varying thicknesses are presented.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.145-151
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• 2019

The fragility analyses for the partially filled horizontal cylindrical tank having a flexible wall were conducted to evaluate seismic performance. An equivalent simplified model with two lumped masses representing to impulsive and convective masses was used to represent the liquid storage system. This simplified model was validated by comparing its time history analysis results with the 3D FSI model results. The horizontal tank was analyzed under bi-directional excitations. Seismic fragility curves for the stability were developed in transverse and longitudinal directions. Fragility curves show that seismic damage for the horizontal storage system is more susceptible in the transverse direction.

• Earthquakes and Structures
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• v.14 no.2
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• pp.95-102
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• 2018

Seismic fragility curves of concrete cylindrical tanks are determined using the finite element method. Vulnerabilities including sloshing of contents, tensile cracking and compression failure of the tank wall due to bending are accounted for. Effects of wall flexibility, fixity at the base, and height-diameter ratio on the response are investigated. Tall, medium and squat tanks are considered. The dynamic analysis is implemented using the horizontal components of consistent earthquakes. The study shows that generally taller tanks are more vulnerable to all of the failure modes considered. Among the modes of failure, the bending capacity of wall was shown to be the critical design parameter.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.487-496
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• 2002

Hydrodynamic behavior and response of vertical-cylindrical liquid-storage tank is considered. The equation of the liquid motion is shown by Laplace's differential equation with the fluid velocity potential. The solution of the Laplace's differential equation of the liquid motion is expressed with the modified Bessel functions. Only rigid tank is studied. The equivalent masses and heights for the tank contents are presented for engineering design model.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.7-14
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• 2011

Numerical simulations were performed for the evaluation of wave and current loads on a fixed cylindrical substructure model for an ocean wind turbine using the ANSYS-CFX package. The numerical wave tank was actualized by specifying the velocity at the inlet and applying momentum loss as a wave damper at the end of the wave tank. The Volume-Of-Fluid (VOF) scheme was adopted to capture the air-water interface. An accuracy validation of the numerical wave tank with a truncated vertical circular cylinder was accomplished by comparing the CFD results with Morison's formula, experimental results, and potential flow solutions using the higher-order boundary element method (HOBEM). A parametric study was carried out by alternately varying the length and amplitude of the wave. As a meaningful engineering application, in the present study, three kinds of conditions were considered, i.e., cases with current, waves, and a combination of current and progressive waves, passing through a cylindrical substructure model. It was found that the CFD results showed reasonable agreement with the results of the HOBEM and Morison's formula when only progressive waves were considered. However, when a current was included, CFD gave a smaller load than Morison's formula.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.262-267
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• 2017

The number of shops needed for the fabrication of a sphere type cargo tank for an LNG carrier is proportional to the size of the tank to be constructed. Due to the limitations of facility investment, it is difficult to fabricate various size tanks with a perfectly spherical shape in the (factory). An efficient method of increasing the capacity of the cargo tank is to extend the conventional sphere type LNG tank vertically by inserting a cylindrical shell structure. In this study, equations for the dynamic pressure distribution due to horizontal acceleration are derived for a sphere type LNG tank with central extension. The derived equations can be easily applied to the design and structural assessment of a sphere type LNG tank with central extension. Furthermore, the results of this study can be combined with the static design loads previously reported by Shin & Ko [9], in order to establish a simplified analysis method which enables a precise initial estimate to be obtained, thereby obviating the need for a time consuming finite element analysis.