• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1087-1090
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• 2003

In this study, experimental procedures were suggested to investigate the sloshing behavior of a liquid storage tank subjected to inevitably external vibrating conditions. For this purpose. liquid storage tank with rectangular cross section was made of an acrylic resin for the visualization of liquid fluctuation. A specially designed vibrator was used to provide a specified vibrating condition to the liquid storage tank. Extrapolation technique was applied to determine sloshing natural frequency by using various sloshing frequencies at each vibrating displacement and liquid contents at a fixed vibrating frequency. Sloshing mode was also determined from continuous images or liquid fluctuation captured from a video camera. In addition, change in the height of the liquid free surface was measured by using a floating target and a laser displacement sensor. It is found that the suggested method can be applicable to identify the sloshing behavior of liquid storage tank with rectangular cross section.

• 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.

• Structural Engineering and Mechanics
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• v.65 no.5
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• pp.557-572
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• 2018

The academic research works about liquid storage tanks are reviewed for the purpose of providing valuable reference to the engineering practice on their aseismic design. A summary of the performance of tanks during past earthquakes is described in this paper. Next, the seismic response of tanks under unidirectional earthquake is reported, supplemented with the dynamic response under multidirectional motions. Then, researches on the influence of soil-structure interaction are brought out to help modify the seismic design approach of tanks in different areas with variable properties of soils. Afterwards, base isolation systems are reported to demonstrate their effectiveness for the earthquake-resistant design of liquid storage tanks. Further, researches about the liquid-structure interaction are reviewed with description of simplified models and numerical analytical methods, some of which consider the elastic effect of tank walls. Moreover, the liquid sloshing phenomenon on the hydrodynamic behaviors of tanks is presented by various algorithms including grid-based and meshfree method. And then the impact of baffles in changing the dynamic characteristics of the liquid-structure system is raised, which shows the energy dissipation by the vortex motion of liquid. In addition, uplifting effect is given to enhance the understanding on the capacity of unanchored tanks and some assessment of their development. At last, the concluding remarks and the aspects of extended research in the field of liquid storage tanks under seismic loads are provided, emphasizing the thermal stress analysis, the replaceable system for base isolation, the liquid-solid interaction and dynamic responses with stochastic excitations.

• Journal of the Earthquake Engineering Society of Korea
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• v.26 no.5
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• pp.203-209
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• 2022

A simplified method for earthquake response analysis of a rectangular liquid storage tank is proposed with fluid-structure interaction considered. In order to simplify the complex three-dimensional structural behavior of a rectangular liquid storage tank, it is assumed that structural deformation does not occur in the plane parallel to the direction in which the earthquake ground motion is applied but in the plane perpendicular to the direction. The structural deformation is approximated by combining the natural modes of the simple beam and the cantilever beam. The hydrodynamic pressure, the structure's mass and stiffness, and the hydrodynamic pressure's added mass are derived by applying the Rayleigh-Ritz method. The natural frequency, structural deformation, pressure, effective mode mass, and effective mode height of the rectangular liquid storage tank are obtained. The structural displacement, hydrodynamic pressure, base shear, and overturning moment are calculated. The seismic response analysis of an example rectangular liquid storage tank is performed using the proposed simplified approach, and its accuracy is verified by comparing the results with the reference solution by the finite element method. Existing seismic design codes based on the hydrodynamic pressure in rigid liquid storage tanks are observed to produce results with significant errors that cannot be ignored.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.653-660
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• 2022

In liquid hydrogen storage tanks, tank damage or leakage in the surrounding pipes possess a major risk. Since these tanks store huge amounts of the fluid among all the liquid hydrogen process facilities, there is a high risk of leakage-related accidents. Therefore, in this study, we conducted a risk assessment of liquid hydrogen leakage for a grid-type liquid hydrogen storage tank (lattice-type pressure vessel (LPV): 18 m³) that overcame the low space efficiency of the existing pressure vessel shape. Through a commercially developed three-dimensional computational fluid dynamics program, the geometry of the site, where the liquid hydrogen storage tank will be installed, was obtained and simulations of the leakage scenarios for each situation were performed. From the computational flow analysis results, the pool formation behavior in the event of liquid hydrogen leakage was identified, and the resulting damage range was predicted.

• Progress in Superconductivity and Cryogenics
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• v.22 no.4
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• pp.45-50
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• 2020

In this research, the variation of round-trip efficiency in a liquid air energy storage system (LAES) is calculated and an optimal configuration is found. The multiple stages of cold energy storage are simulated with several materials that process latent heat at different temperature ranges. The effectiveness in the charging and discharging processes of LAES is newly defined, and its relationship with the round-trip efficiency is examined. According to defined correlation, the effectiveness of the discharging process significantly affects the overall system performance. The round-trip efficiency is calculated for the combined cold energy storage materials of aqueous dimethyl sulfoxide (DMSO) solution, ethanol, and pentane theoretically. The performance of LAES varies depending on the freezing point of the cold storage materials. In particular, when the LAES uses several cold storage materials, those materials whose freezing points are close to room temperature and liquid air temperature should be included in the cold storage materials. In this paper, it is assumed that only latent heat is used for cold energy storage, but for more realistic analyzes, the additional consideration of the transient thermal situation to utilize sensible heat is required. In the case of such a dynamic system, since there is certainly more increased heat capacity of the entire storage system, the volume of the cold energy storage system will be greatly reduced.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.98-105
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• 2002

The effects of the base-isolation system and elastic soil foundation on the behavior of a liquid storage tank are studied. To evaluate the seismic response of liquid storage tank accurately, the coupled dynamic system considering base isolation and soil interaction problem is formulated in time domain. Results show that the base isolation system reduces effectively the radial displacements, base shears, overturning moments, axial resultant stresses and the hydrodynamic pressure by providing flexibility and energy dissipation capability. Base Isolation may, however, increase the relative liquid sloshing amplitude due to the effect of liquid-structure interaction and cause excessive large relative displacements between structure and foundation. In addition to base-isolator, the dynamic behavior of liquid storage tank is related to the flexibility of base foundation, so the analysis of soil-structure interaction s achieved.

• Korean Journal of Organic Agriculture
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• v.13 no.2
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• pp.129-143
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• 2005

Attempting to make an economic valuation of semi-liquid manure raises various complex questions. These are the valuation under different farming conditions, cost-benefit analysis in connection with the investment requirements of different semi-liquid manure systems, different storage capacities, transportation distances and treatment procedures. In the following, there questions will be discussed : 1. What value do the different types of semi-liquid manure have under different farming conditions? 2. Which storage capacities are economically justified? 3. Under which conditions is the transport of semi-liquid manure over long distances profitable?

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.314-317
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• 2002

The sloshing phenomenon sometimes happens to be occurred in the liquid storage tank due to the unexpected and/or inevitable vibrating conditions and may result in severe effects on the structural stability. This study deals with the development of experimental techniques for the evaluation of sloshing behavior in the liquid storage tank and for the identification of natural frequencies and mode shapes by varying with various vibrating conditions. In addition, suitable method is suggested to minimize the sloshing effect on the liquid storage tank and its validity is experimentally investigate d.

• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.109-116
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• 2004

The dynamic behavior of the rectangular liquid storage structure is known to be greatly influenced by fluid-structure interaction. By mounting the liquid storage structure on the properly designed base isolators, dynamic response of the superstructure can be reduced. However, base isolators inevitably incur large displacement of the structure to the ground ·ind may give adverse effects on the sloshing height. This paper presents the analysis method for fluid-structure-isolator interaction in base-isolated rectangular liquid storage structures. In the method, the irrotational motion of invicid and incompressible ideal fluid is expressed by analytic solutions and the superstructure and isolators are properly modeled by finite element and bilinear model. Free surface sloshing motion, hydrodynamic pressure acting on the wall and structural response are obtained by the presented method.