• 한국해양공학회지
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• 제15권3호
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• pp.35-42
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• 2001

The characteristics of tidal circulation with the flow-control structures using the three-dimensional numerical model (POM, Princeton Ocean Model) of Chinhae Bay, Korea were investigated. To confirm th efficiencies of flow-control structures, the training wall and submerged training wall were constructed at the mouth and narrow channel in Chinhae Bay. On the basis of the present investigation, the tidal circulation induced by the construction of flow-control structures could enhance the water exchange improvement appropriately. And, th training wall at the central is more dominated than the other structures for the efficient of water exchange. The sites and types of structure and flow patterns seem to be very sensitive in tidal simulation and changes in flow fields.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.431-434
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• 2006

This study reviews the properties of coastal ocean and Seomjin River estuary spaces then define some MGIS(Marine Geographic Information System) related terminologies for clarifying the scope of MGIS boundaries. Therefore, we show the three-dimensional circulation of MGIS-based Seomjin River Estuary integrating three-dimensional POM model and observed data.

• 한국환경과학회지
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• 제5권6호
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• pp.727-738
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• 1996

An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

• 한국해안해양공학회지
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• 제10권1호
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• pp.27-36
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• 1998

물의 유동을 해석하기 위한 3차원 수치모형이 개발되었다 모형은 균질류에 대한 $\sigma$-좌표에서 방정식들 을 유한요소법을 사용하여 해석한다. 모형의 정확성을 정토하기 위하여 1차원 수로에서 취송류 분포, 정사각형 호수에서 취송류 분포를 해석하고 해석해와 비교 검증하였으며, 마산-진해만에서 조류분포를 계산하고 현장 관측자료와 비교 검증하였다. 계산결과가 비교된 해석해 및 관측치와 대체로 일치하는 양호한 결과를 보였다. 따라서, 개발된 모형은 복잡한 육지경계를 갖는 자연 수괴의 3차원적 순환현상을 해석하는 데 널리 활용될 수 있을 것이다

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.466-475
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• 2017

Coolant mixing under natural circulation flow regime constitutes a key parameter that may play a role in the course of an accidental transient in a nuclear pressurized water reactor. This issue has motivated some experimental investigations carried out within the OECD/NEA PKL projects. The aim was to assess the coolant mixing phenomenon in the reactor pressure vessel downcomer and the core lower plenum under several asymmetric steady and unsteady flow conditions, and to provide experimental data for code validations. Former studies addressed the mixing phenomenon using, on the one hand, one-dimensional computational approaches with cross flows that are not fully validated under transient conditions and, on the other hand, expensive computational fluid dynamic tools that are not always justified for large-scale macroscopic phenomena. In the current framework, an unsteady coolant mixing experiment carried out in the Rossendorf coolant mixing test facility is simulated using the three-dimensional porous media capabilities of the thermal-hydraulic system CATHARE code. The current study allows highlighting the current capabilities of these codes and their suitability for reproducing the main phenomena occurring during asymmetric transient natural circulation mixing conditions.

• Korean Circulation Journal
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• 제53권12호
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• pp.826-828
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• 2023

• 한국해안해양공학회지
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• 제6권1호
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• pp.1-11
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• 1994

곡선형격자 삼차원 수치모델이 소개되며 바람에 의한 물의 순환을 계산하기 위하여 얕은 호수에서 적용되었다. 수치모델의 결과가 실측자료와 비교되었으며, 바람이 점차 증가할 때 물의 성층에 의한 효과가 좋은 계산 결과를 얻기 위하여 결정적임을 알 수 있었다. 기상자료가 불충분할 때 소위 Inverse Method가 물 표면에서 열흐름을 추정하기 위하여 사용되었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1998년도 학술발표회 논문집
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• pp.632-637
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• 1998

The purpose of this study of this study is to find tide and tidal current variation by three dimensional numerical model of tide and tidal current in the bay of Cheonsu in Korea. On the basis of the observed data on water temperature and salinity data and wind data of summer(July) in the bay of Cheonsu in Korea, water circulation in the bay of Cheonsu is investigated with use of a robust diagnostic numerical model, including calculated co-range and co-tidal charts of M2 tide are similar to the observed ones. The residual flow Pattern at the surface layer during summer formed clockwise circulation in the front coastal the dike of the Sosam A zone(Ganwor island) and Taeju island. The residual flow pattern at the 15m layer during formed clockwise circulation in the front Taeju island. The residual flow Pattern at the surface layer formed anti-clockwise circulation in the upper Sangmok and Naepasu island.

• Journal of Power Electronics
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• 제16권6호
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• pp.2085-2098
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• 2016

Laminated busbars with a low stray inductance are widely used in NPC three-level inverters, even though some of them have poor performances in heat equilibrium and overvoltage suppression. Therefore, a theoretical method is in need to establish an accurate mathematical model of laminated busbars and to calculate the impedance and stray inductance of each commutation loop to improve the heat equilibrium and overvoltage suppression performance. Firstly, an equivalent circuit of a NPC three-level inverter laminated busbar was built with an analysis of the commutation processes. Secondly, on the basis of a 3D (three dimensional) cubical thermal model and mirror circulation theory, a supersymmetric mirror circulation 3D cubical thermal model was built. Based on this, the laminated busbar was decomposed in 3D space to calculate the equivalent resistance and stray inductance in each commutation loop. Finally, the model and analysis results were put into a busbar design, simulation and experiments, whose results demonstrate the accuracy and feasibility of the proposed method.

• 한국해안해양공학회지
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• 제4권1호
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• pp.45-58
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• 1992

황해 및 동중국해에서 기상학적으로 유발된 연여균 및 계절적 해류 순환을 산정하기 위해 3次元 수치모형이 이용되었는데 수치모형은 불규칙한 연안경계와 실제 수심을 반영할 수 있도록 구성되었다. 본 연구에서는 전회의 동중국해의 3차원 수치모형 (Choi, 1984)을 제붕역에서의 흐름을 좀더 자세히 재현할 수 있도록 세분화하였는데 모형에 사용된 유한격자체계의 해상도는 위도 4분과 경도 5분으로 구성되었으며 황해 및 동중국해상에서 유속의 3차원적 순환 형태가 산정되어 제시되었다. 수치모형에 의해 계산된 기상학적으로 유발된 恒流 유원은 이 해역의 여러 영역에서 수심(표면, 중간수심, 바닥)別 및 전체 水柱에 대해 해수 문체시간을 계산하는데 이용되었다.