• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
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• pp.583-588
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• 1997

For the efficient current drive, the structure of ICRF wave propagation and absorption in a tokamak plasma should be first investigated. In this paper, two dimensional study on FWCD as well as ICRF minority ion heating for the KSTAR [Korea Superconducting Tok Amak Research] [1] plasma was performed using the full wave code of TORIC [2]. The ICRF wave propagation and absorption structures, the competitive power absorption between electrons and ions and the coupling of antenna/plasma are investigated.

• 한국해양공학회지
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• 제20권4호
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• pp.64-69
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• 2006

A numerical analysis is made to investigate the wave absorption efficiency of a OWC-type wave power generator. Energy absorption by an OWC(Oscillating Water Column) air-chamber is computed in regular waves, taking account of the oscillating surface-pressure, due to pressure drop, across the duct of the air chamber. The problem is formulated in the scope of potential theory and solved by the Localized Finite Element Method(LFEM), based on the classical variational principle. The efficiency of energy absorption is investigated by. changing wave conditions, sea-bottom slope and pressure drop coefficient.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.621-625
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• 2007

Oscillating wave amplitude in a bottom-mounted owe chamber designed for wave energy converter is investigated by applying characteristic wave conditions in Korean coastal water. The effects of shape parameters of OWC chamber in a view of wave energy absorbing capability are analyzed. Both experimental and numerical approaches are adopted and their results are compared to optimize the shape parameters which can result in a maximum power production under given wave distribution. The experiment was carried out in a wave flume under 2-D assumption of OWC chamber. In numerical scheme, the potential problem inside the chamber is solved by use of the Green integral equation associated with the Rankine Green function, while outer problem with the Kelvin Green function taking account of fluctuating air pressure in the chamber. Air duct diameter, chamber width, and submerged depths of front skirt and back wall of chamber changes the magnitude and peak frequency of wave absorption significantly.

• 동력기계공학회지
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• 제17권5호
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• pp.38-43
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• 2013

In order to design a wave energy generating system, a 6-DOF analysis technique is applied to CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming waves. A spring constant is adopted to control the motion of multi floating bodies and to calculate the total average power absorption. Three cases of different wavelengths namely 20D, 30D and 40D have been modeled to analyze the total average power absorption. The average power absorption not only varies with the position of the floating body but also varies with wavelength. From the results obtained, it is concluded that the maximum total average power absorption is 9W approximately in wavelength 30D and the minimum total average power absorption is 4.3W approximately in wavelength 40D.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.47-52
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• 2010

근해에 설치되는 3차원 착저식 OWC 파력발전 챔버 구조물의 파 에너지 흡수효율과 구조물에 작용하는 1차 및 시간 평균 2차 파랑하중의 해석기법을 보였다. 쌍동형 OWC챔버 내부의 변동압력을 각 챔버의 내부 자유표면 경계조건에 도입하였으며 챔버 내부는 Rankine, 외부는 유한수심 3차원 자유표면 Green함수에 연계된 하이브리드 적분방정식을 사용하여 포텐셜 유동을 해석하였다. 수치실험 결과로서 3차원 착저식 OWC 파일럿 플랜트의 파력발전 1차변환 효율과 구조물에 작용하는 반복 및 지속적인 파랑하중을 제시하였다.

• 대한기계학회논문집A
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• 제40권6호
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• pp.557-563
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• 2016

파력발전시스템의 에너지 흡수 효율은 입사파의 파력과 발전기 구동 동력의 비로 정의된다. 흡수 효율은 파력발전시스템의 동적 거동에 의존하기 때문에 파력발전시스템의 에너지 흡수 효율을 예측하기 위해서 파력발전시스템의 동적 해석이 요구된다. 본 논문에서는 에너지 흡수 효율을 예측하기 위하여 파력발전시스템의 동적 해석을 수행하였다. 파력발전시스템의 동적 해석을 위해서 상용 다물체동역학 해석 프로그램인 RecurDyn을 사용하였고, 부유체에 작용하는 파력을 모델링하기 위해서 Morison equation을 적용하였다. 효율분석 결과 파고가 낮고, 주기가 짧을수록 흡수효율이 높아지는 경향을 보인다.

• 한국해양환경ㆍ에너지학회지
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• 제10권3호
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• pp.173-180
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• 2007

파력에너지 변환을 위해 설계된 착저식 진동수주형 공기실 내의 파진폭 변화를 우리나라 연안의 특징적인 파랑 조건을 적용하여 조사하였다. 진동수주형 공기실의 형상인자가 파력에너지 변환에 미치는 영향을 파력에너지의 흡수 효율 관점에서 분석하였다. 실험적 및 수치적 접근법을 함께 사용하여 그 결과들을 상호 비교하였으며, 주어진 파랑 분포 하에서 파력에너지 흡수가 최대가 되는 형상인자들의 최적화를 목적으로 연구가 수행되었다. 실험은 공기실의 이차적원 형상을 가정하여 이차원 조파수조에서 실시되었으며, 수치적 해석은 공기실 내에서는 변동하는 공기압을 고려할 수 있도록 Rankine Green 함수를 적용하고 공기실 밖에서는 Kelvin Green 함수를 적용하는 합성 적분방정식에 기초하여 수행되었다. 공기실 상부의 덕트 직경, 공기실 폭, 공기실 전면벽 및 후면벽의 깊이는 흡수되는 파력에너지의 크기와 정점 주기를 민감하게 변화시키는 주요한 형상인자들임을 확인하였다.

• 한국해양공학회지
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• 제14권2호
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• pp.1-6
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• 2000

Wave energy absorption by a flap equipped with a harbor in a water of finite depth is studied. The wave potential is calculated by a hybrid integral equation consisting of Green integral equations associated with Rankine and Kelvin Green functions. The absorbed wave energy is calculated by both the near-field and far-field methods. The present methods can be used for the design of a flap-harbor wave energy absorber since the numerical results by the two methods are in good agreement.

• 한국자동차공학회논문집
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• 제4권3호
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• pp.83-91
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• 1996

This paper investigates the energy absorption characteristics of thin-walled rectangular tubes. In the compact mode, the crushing process of a thin-walled tube is analyzed into 3 parts by the ratio of outward to inward fold length. The mean crush load and the half-wave folding length are determined by using minimum energy principle. The effective crush distance can be determined when half-wave folding length is known, and the number of folds is derived when crush distance is given. Thus when the crush distance is given, energy absorption capacity can be estimated with mean crush load and number of folds. And the theoretical value is proven experimentally.

• Bulletin of the Korean Chemical Society
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• 제27권8호
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• pp.1186-1188
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• 2006

In this paper a new theory is presented to treat the problem of stimulated absorption and emission of photons between energy levels from the standpoint of discrete quantum jumps. In order to implement the theory a scheme to avoid the quantum Zeno effect is proposed. Numerical simulations are performed to demonstrate that this approach does not contradict the principles of the standard wave mechanics. It is shown that with this approach one can obtain photon observation statistics as well.