• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.102-110
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• 2023

With the global shift from a carbon-based economy to a hydrogen-based economy, understanding the sloshing phenomenon and its impact on boil-off rate (BOR) in liquid hydrogen (LH2) tank trailers is crucial. Here, we analyze the primary breakup process under sloshing phenomena in a liquid fuel tank. We observe the growth of multiple holes on the sheet-like structures and the formation of ligament structures reminiscent of jet atomization. Through the extraction of three-dimensional liquid regions, we analyze the geometrical characteristics of these regions, enabling the classification of sheets, ligaments, and droplets. The present findings could contribute to understanding the breakup mechanism and hold potential for the development of strategies aimed at minimizing BOR.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.584-589
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• 2000

When the liquid tanks only partially filled and under translational acceleration, large quantities of liquid move uncontrollably inside the tanks and generate the liquid sloshing effect. Liquid sloshing effect could be a severe problem in launch vehicle stability and control if the liquid modes of motion couple significantly with the launch vehicle's normal modes of motion. Several methods have been employed to reduce the effect of sloshing, such as introducing baffles inside the tanks or dividing a large tank into a number of smaller ones. These techniques, although helpful in some cases, do not succeed in canceling the sloshing effects. In this paper, An attitude controller is designed for a launch vehicle with liquid sloshing effect. Both PD controller and sloshing filter are designed for the objective. PD gains and design parameters are determined by optimal algorithm. The performance of the attitude controller is evaluated via computer simulations.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.85-89
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• 2013

The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid- structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the basic insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.859-860
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.617-618
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1018-1024
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• 2011

Liquid sloshing occurs when a partially filled liquid tank is subjected to undesirable external forces or acceleration/deceleration for positioning control. Installation of baffles is still the most popular way to suppress the sloshing, but recent successes of input shaping in reducing structural vibrations may give a possible alternative. We aim at investigating the applicability of input shaping to sloshing suppression by numerically solving fluid motions in a rectangular tank. The tank is partially filled with water and it is suddenly put into a sequence of horizontal motions of acceleration and constant speed. The flow is assumed to be two-dimensional, incompressible, and in viscid, and a VOF two-phase model is used to capture the free surface. Results show that the sloshing can be successfully suppressed by shaping the input, i.e., the velocity or acceleration profile of tank. Three different input shapers (ZII, ZVD, and two-mode convolved ZV shapers) are tested and compared in this study Among them, the convolved ZV shaper shows a best performance to eliminate the sloshing almost completely.

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.106-115
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• 2019

The interaction between a sloshing liquid damper (SLD) tank and a rectangular pontoon was investigated under the assumption of the linear potential theory. The eigenfunction expansion method was used not only for the sloshing problem in the SLD tank but also for analyzing the motion responses of a rectangular pontoon in waves. If the frictional damping due to the viscosity of the SLD tank was ignored, the effect of the SLD appeared to be an added mass in the coupled equation of motion. The installation of the SLD tank had a greater effect on the roll motion response than the sway and heave motion of the pontoon. One resonance peak for rolling motion showed up in the case of a frozen liquid in the SLD tank. However, if liquid motion in the SLD tank was allowed, two peaks appeared around the first natural frequency of the fluid in the SLD tank. In particular, the peak value located in the low-frequency region had a relatively large value, and the peak frequency located in the high-frequency region moved into the high-frequency region as the depth of the liquid in the tank increased.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.172-175
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• 2002

Sloshing of fuel in a liquid propellant tank is an important part of the dynamic and the stability analysis of the rocket. Baffles are installed in a propellant tank to reduce the instability due to sloshing. Multi degree of spring-mass-damper model was used to model sloshing of fuel in an axisymmetric tank. The natural frequencies and damping ratios are estimated. In order to verify the estimated natural frequencies and damping ratios, tests are performed for the real propellant tank of KSR-III with single ring baffle. Results of fuel sloshing analysis are compared with those of tests.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.161-165
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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 phenomena of liquid inside a tank can suppress movement of the tank subject to external excitations at specific frequency. The effects of sloshing phenomena inside a rectangular floating body on its sway motion are investigated by varying excitation frequency. First, a grid-refinement study is carried out to ensure validity of grid independent numerical solutions using present numerical techniques. Then, sway motion of the floating body subjected to wave with five different frequencies are simulated. The normalized amplitudes of sway motion of the target floating body are compared over the frequency, for 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 excitation frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.534-537
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• 2012

Hydroelastic effects on sloshing phenomena in a rectangular tank are numerically investigated. The dimension of the tank is $1000mm{\times}600mm$, and the filling ratio of water is 20% of tank height. One of the side walls of tank is assumed to be flexible. The tank is excited into sway motion with amplitude of 100mm and frequency of 0.53Hz that is first natural frequency of water inside the tank. Prediction results for time histories of pressure and displacement of flexible and rigid walls are compared to quantitatively assess hydroelastic effects on sloshing phenomena.