• Journal of the Society of Naval Architects of Korea
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• v.35 no.4
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• pp.27-37
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• 1998

The sloshing is very important in a safe transport of the liquid cargo by a ship. With the increasing number of supertanker and LNG carriers, this problem has become increasingly more important. In order to study the magnitude and characteristics of impact pressures due to sloshing, experiments ware performed with a rectangular tank and compared with numerical results. Structural responses of tank wall under impulsive pressures were measured. Structural vibrations induced by the sloshing load were analysed by including hydroelastic erects in terms of added mass and damping. To check the validity of the numerical model, the natural frequencies of plate in air and water were compared with measurements, and a good agreement was found. In the case that a plate vibrates under impulsive loads, the pressure on the flexible plate is larger than that on the rigid plate without hydroelastic effects, which was confirmed experimentally. The frequency of oscillatory pressure as well as accel%pion coincides with the natural frequency of plate in water.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.496-497
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.719-721
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• 2014

• Bulletin of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.13-20
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• 1996

해양공간 활용을 위해 예상되는 부유식 해양구조물은 단위구조들이 결합된 형태의 초대형 구조물로서 단위 구조물간의 탄성변형 문제가 매우 중요시되고 있으며 이에 따라 단위구조물간의 상호작용이 고려된 유체력 산출과 탄성응답이 고려된 해석법의 개발이 전세게적으로 활발히 이루어지고 있다. 독립 부유구조물 자체의 크기가 대형화될 때 발생하는 탄성 변형 또한 구조 해석 및 진동관점에서 중요한 고려사항이며, 이는 조선공학분야에서 유탄성 해석기법에 바탕을 두고 연구가 활발히 진행중이다. 본 고에서는 부유구조물의 설계에 있어 핵심기술중 하나인 파랑응답 해석기술의 현황에 대해 살펴보고 현재 한국기계연구원에서 수행중인 국책연구개발사업 "해양공간이용 대형 복합플랜트 개발"의 세부과제인 "부유구조물 파랑응답 해석기법 개발"의 추진내용에 대해 환경 하중/응답해석기술, 계류시스템 설계/해석기술, 유탄성응답 해석기술로 나누어 소개하고자 한다. 해석기술로 나누어 소개하고자 한다.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.85-89
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• 2013

In the engine room and the aft body, there are so many fluid tanks such as fresh water tank and oil tank. The vibration analysis for the fluid tank structures has to consider the added mass effect due to the fluid. However, it is known that the result of the fluid tank has the difference according to the boundary condition of the fluid field such as infinite fluid and finite fluid. In this paper, a numerical case study is carried out for the research about the vibration characteristics of the fluid tank with various fluid field. In addition, an experimental study is carried out to verify the validity of the vibration analysis for the fluid tank structure.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.855-860
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• 2006

In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(Virtual Mass Method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.65-68
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• 2005

In this paper, a theoretical study is carried out on the hydroelastic vibration of a rectangular tank wall. It is assumed that the tank wall is clamped along the plate edges. The fluid velocity potential is used for the simulation of fluid domain and to obtain the added mass due to wall vibration. In addition, the vibration characteristics of stiffened wall of the rectangular tank are investigated. Assumed mode method is utilized to the stiffened plate model and hydrodynamic force is obtained by the proposed approach. The coupled natural frequencies are obtained from the relationship between kinetic energies of a wall including fluid and the potential energy of the wall. The theoretical result is compared with the three-dimensional finite element method and then added mass effect is discussed due to tank length and potential mode.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.1 s.118
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• pp.3-9
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• 2007

In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(virtual mass method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

• Journal of Ocean Engineering and Technology
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• v.22 no.1
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• pp.22-29
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• 2008

A numerical investigation is made on the effects of the location and shape of the front wall of an OWC(Oscillating Water Column) chamber on the hydroelastic response of a VLFS. Most of the studies on the effects of an OWC chamber on the response of a VLFS have assumed the location of the OWC chamber to be at the front of the VLFS. In the present study, an OWC-chamber is introduced at an arbitrary position in relation to a VLFS to determine the influence of the location and shape of the OWC chamber on the hydroelastic response of the VLFS. A finite element method is adopted as a numerical scheme for the fluid domain. or the finite element method, combined with a mode superposition method, is applied in order to consider the change of mass and stiffness The OWC chamber in a piecewise constant manner. or the facilitated anefficient analysis of The hydroelastic response of the VLFS, as well as the easy modeling of different shape and material properties for the structure. Reduction of hydroelastic response of the VLFS is investigated for various locations and front wall shapes of the owe chamber.