• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.113-120
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• 2006

In this paper, generation mechanisms of ocean freak waves are briefly introduced in the context of wave-current interaction phenomena. As an accurate and efficient numerical tool, the spectral element method is presented with general features and specific treatment for the wave-current interaction problem. The present model of the fluid motion is based on the Navier-Stokes equations incorporating a velocity-pressure formulation. In order to deal with the free surface motion, an Arbitrary Lagrangian-Eulerian (ALE) description is adopted. As an intermediate stage of development, solution procedure and characteristic aspects of the present modeling and numerical method features are addressed in detail, and numerical results for wave-current interaction is left as further study.

• 한국해양공학회지
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• 제20권1호
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• pp.48-54
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• 2006

In this paper, flowfield and acoustic-field around moving bodies are simulated by the Arbitrary Lagrangian Eulerian (ALE) formulation in the finite difference lattice Boltzmann method. Some effects are checked by comparing flaw about a square cylinder in ALE formulation and that in the fixed coordinates, and both agree very well. Matching procedure between the moving grid and fixed grid is also considered. The applied method in which the both grids are connected through buffer region is shown to be superior to moving overlapped grid. Dipole-like emissions of sound wave from harmonically vibrating bodies in two- and three-dimensional cases are simulated.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.460-470
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• 2004

A computational analysis of engineering problems with moving domain or/and boundary according to either Lagrangian or Eulerian approach may encounter inherent numerical difficulties, the extreme mesh distortion in the former and the material boundary indistinctness in the latter. In order to overcome such defects in classical numerical approaches, the ALE(arbitrary Lagrangian Eulerian) method is widely being adopted in which the finite element mesh moves with arbitrary velocity. This paper is concerned with the ALE finite element formulation, aiming at the dynamic response analysis of baffled fuel-storage container in yawing motion, for which the coupled time integration scheme, the remeshing and smoothing algorithm and the mesh velocity determination are addressed. Numerical simulation illustrating theoretical works is also presented.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.557-560
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• 2011

In the present paper, the sloshing resistance performance of an LNG carrier insulation system is evaluated by fluid-structure interaction (FSI) analysis. For this analysis, the arbitrary Lagrangian Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG motion of a KC-1 type LNG carrier cargo tank. In addition, the global-local analysis method is introduced to reduce computational time and cost. The global model is built from shell elements to reduce the sloshing analysis time. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.248-249
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• 2005

In this paper, flowfield and acoustic-field around moving bodies are simulated by the Arbitrary Lagrangian Eulerian (ALE) formulation in FDLBM. The effect of the ALE is checked by comparing flow about a square cylinder in ALE formulation and that in the fixed coordinates, and the results show good agreement. Matching procedure between the moving grid and fixed grid is also considered. The applied method in which the both grids are connected through buffer zone is shown to be superior to moving overlapped grid. Dipole-like emissions of sound wave from harmonically vibrating bodies in 2- and 3-dimensional cases are simulated.

• 항공우주시스템공학회지
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• 제2권2호
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• pp.1-7
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• 2008

Recently the wind energy has been alternatively used as a renewable energy resource instead of the mostly used fossil fuel due to its lack and environmental issues. This work is to propose a structural design and analysis procedure for development of the low noise 100W class small wind turbine system which will be applicable to relatively low speed region like Korea and for the domestic use. Structural analysis including load cases, stress, deformation, buckling, vibration and fatigue life was performed using the Finite Element Method, the load spectrum analysis and the Miner rule. In order to evaluate the designed structure, the structural test was carried out and its test results were compared with the estimated results. In addition, the blade should be safe from the impact damage due to FOD(Foreign Object Damage) including the bird strike. In order to analize the bird strike penomena on the blade, MSC. Dytran was used, and the applied method Arbitrary Lagrangian-Eulerian was evalud by comparison with the previous study results.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.553-556
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• 2011

The primary aim of the present study is to propose new design formulae that can be used to evaluate the structural performance of breakwaters installed on container carriers under green water impact loads. A series of numerical analyses for green water impact loads inducing breakwater collapse have been carried out. The well-known fluid-structure interaction analysis technique has been adopted realistically to consider the phenomenon of green water impact loads. The structural behavior of these breakwaters under green water impact loads has also been carried out simultaneously throughout the transient analysis. A verification study of the numerical results was performed using the actual collapse incidents of breakwaters on container carriers. It would be expected that the proposed design formulae, based on the obtained insights, could be used as practical guidelines for the design of breakwaters on container carriers.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2120-2134
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• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.173-176
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• 2009

본 논문은 유동과 구조물간의 상호작용으로 인해 유체나 구조, 한 쪽 분야에서의 접근으로는 한계가 있는 고체 로켓 내부 유동-구조-연소 결합 문제를 해결하기 위해 FSI를 이용한 전산해석을 목적으로 한다. ALE(Arbitrary Lagrangian Eulerian) 기술 방식을 도입하여 계산 격자의 움직임을 허용하면서도 격자에 대한 연속체 입자의 상대운동이 가능하도록 하였다. 유체 영역의 해석 프로그램은 2차원 압축성 비정상 유동 해석을 위한 오일러 방정식을 ALE 형태를 변형시켜 적용 하였고, 고체 영역의 해석 프로그램은 ALE를 고려한 2차원 동적 유한 요소 방법을 사용하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.181-186
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• 2006

본 논문에서는 Freak Wave의 생성원인에 대하여 간략히 논의하였으며, 이 중 파랑-조류 비선형 상호작용에 대한 이론 및 수치적 해석기법의 역사와 장단점 등을 기술한다. 본 연구에서는 파랑-조류 상호작용에 대한 수치모델링 및 해석 기법을 개발하고 있다. 개발 중인 수치해석 기법은 공간적으로 불균일한 조류와 파랑의 비선형 상호작용을 해석하기 위하여 Navier-Stokes 방정식을 이용하여 유동현상을 모델링하였으며, 이산화를 위하여 스펙트랄요소법(Spectral Element Method; SEM)을 이용하였다. 또한 자유표면의 운동을 효과적으로 기술하기 위하여 ALE(Arbitrary Lagrangian-Eulerian)기법을 사용하였다. 본 연구의 유동 모델과 수치해석기법의 과정과 특성, 그리고 장점 등에 대하여 논의하였으며, 초기적인 수치해석 결과를 제시하였다. 이를 바탕으로 개발된 수치해석기법의 정확성 및 수렴성을 확인할 수 있다.