• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.505-511
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• 2009

Vessels on anchoring are frequently dragged due to the increased area of wind pressure by enlargement of ship's size and sudden gust of winds in recent years. In the view point of the ship's navigators, the proper measurements corresponding to the dragging of anchor should be taken into account concerned about the time for the occurring of dragging by the external forces such as wind and wave, the pattern and speed of dragging and the possibility of collisions with any other vessels or obstacles. In this paper, it was examined the actual dragging anchor in T.S. HANBADA due to the wind and waves. From this case, it was found the critical external forces by which she was begun to dragged comparing the force by the wind, frictional resistance, drifting force and ship motion moment with the holding power. Also, through the analysis of the dragging pattern, it was known the alteration range of heading angle, swinging width and dragging speed etc.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.344-346
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• 2012

대산항 씨텍 제3번 돌핀부두에 최초 설계의 접안능력기준을 약간 상회하는 5만 DWT급 VLGC 선박이 접안작업을 할 경우, 돌핀의 용량에 따른 접안작업 동안의 안전성 여부를 대산항만의 입출항 제한 자연 환경조건을 적용하여 선박 계류측면에서의 안전성을 판단하고자 한다. 이를 위하여 대상선박의 부두에서의 최악의 외력조건과 계류장력과의 관계를 OCIMF에서 연구 발표한 결과를 바탕으로 계류안전성 계산공식을 적용하여 계류안전성을 평가하도록 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.137-141
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• 2006

컨테이너를 선박에 양 ${\cdot}$ 적하하는 장비인 컨테이너 크레인은 차폐물이 거의 없는 항만에 설치되며, 계류시 전체 높이가 100m에 달하게 되므로 풍하중에 매우 큰 영향을 받게 된다. 따라서 본 연구에서는 컨테이너 크레인에 작용하는 풍하중을 정확하게 분석하기 위하여 풍력실험과 유한요소해석, 전산유동해석을 통하여 컨테이너 크레인이 받는 풍하중을 분석하였다. 우선 대기 경계층 풍동을 이용한 풍력실험을 수행하여 풍향 및 기계시 위치에 따른 풍력계소를 측정하고, 이를 이용하여 컨테이너 크레인이 받는 풍하증을 분석하였다. 그리고 풍력실험에서 얻어진 반력비를 이용하여 유한요소해석을 수행함으로써 컨테이너 크레인에 작용되는 풍하증과 지지점에서의 전도력을 계산하였다. 마지막으로 전산유동해석을 수행함으로써 컨테이너 크레인 주위의 유동현상을 고찰하고 컨테이너 크레인 표면에서의 풍압력과 풍하중을 실험결과와 비교 ${\cdot}$ 분석하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.55-57
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• 2011

경인 아라뱃길이 2011년 10월 개장을 앞두고 있다. 경인 아라뱃길이 시작되는 경인항 서해갑문 입출거시 예선사용기준에 대한 연구는 선박운항의 경제성 측면에서 매우 중요한 의미를 지닌다고 할 수 있다. 통상 선박의 크기(톤수)에 따른 예선의 소요마력 및 사용 척수는 대상선박의 크기, 모양, 접근수로, 부두시설의 위치 및 종류, 기타 환경조건 등의 영향을 받으며, 선체에 작용하는 수면상부의 풍압력과 수면하부의 유압력을 고려하여 규정하고 있다. 따라서 본 연구에서는 국내외 예선 규정 및 대상선박에 대한 예선 조종시뮬레이션을 통하여 경인항 서해갑문 입출거시 사용되는 예선의 기준을 설정하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.551-555
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• 2009

This study analyzed the cause for mooring chain cut in a naval ship moored, in preparation for a typhoon approach, to a buoy in a shelter. The result of the analysis led to a very interesting fact. That is, while officers usually understood the cut results from the fact that the wind and the tide were stronger than what the mooring chain can hold, according to the study, it was analyzed the impact power at the point where the mooring chain and the ship's body met was a main factor in the cut. Also, it was confirmed that the analytic result of the study is more logical from the point of mathematical analysis and that the cut corresponds to what the then-witnesses stated about the situation.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.537-542
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• 2012

Rolling stocks are often subjected to the effects of natural strong wind or wind pressure caused by the crossing train. These wind pressure cause the falling-off in running stability and overturn safety. It is sometimes reported that trains are blown over by a gust of wind. So, many countries enact regulations to secure the overturn safety for wind speed. In this study, theoretical equations of overturn safety based on multi-body model are derived and analyzed the difference between the result of the solid model and that of multi-body model. In case of multi-body model, it is assumed that the degrees of freedom for carbody and bogie are assigned an independent values respectively. The results show that the latter approach based on multi-body model can access the overturn safety of train and replace the conventional method by using commercial software which is accessing with decrement of wheel load.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.97-102
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• 2020

In this study, one-way fluid structure interaction analysis was adapted to verify the durability of the outdoor evacuation stair structure operated in the event of a fire when wind pressure caused by a typhoon was applied. To this end, flow analysis was performed with the flow field around the structure of the evacuation stair in a steady state, and the durability was analyzed through structural analysis such as structural stress, deformation, and fatigue life using these analysis results by fluid data input data for structural analysis. As a result of flow numerical analysis, the air flow was different according to the shape of the evacuation stair structure, and this flow velocity distribution generated by the total pressure on the structure surface. Through the structural analysis results calculated by this total pressure, the safety factor calculated as the maximum stress value was found to be more than the safety factor, and durability was proven by fatigue life and deformation analysis.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.89-97
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• 2005

Application of proper orthogonal decomposition (POD) and continuous wavelet transform (CWT) is introduced to study wind speed and building roof pressures of flow separation region. In this study, a detailed analysis of the approach wind flow, wind-induced building pressure and the relation between the two fields was carried out using the POD technique and CWT analysis. The results show potential of the application of POD and CWT in characterization of spatio-temporal and spectral properties of the approach wind and its induced dynamic pressure events. Some of findings resulting from the application of this analysis can be summarized as follows: (1) The POD first principal coordinate of the roof pressure in the separated shear layer is closely correlated with the longitudinal component of oncoming flow. (2) The CWT analysis suggests that the extreme peak pressure in the separated shear layer is due to condensed large-scale eddy motions.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.440-441
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• 2011

온난화 등 기후변화의 영향으로 국내에 미치는 태풍의 수와 강도가 점점 증가하는 추세이며, 태풍 및 국지성 돌풍에 의한 송전선로의 과도한 점퍼선 횡진은 점퍼선과 철탑간의 공기절연거리를 감소시켜 지락사고가 발생하는 원인이다. 따라서 점퍼선의 횡진으로 인한 섬락고장을 예방하기 위하여 세계적으로 사용량이 증가하고 있는 폴리머 재질의 애자를 적용하여 전기 기계적 특성을 분석하고 국내 최대 순간풍속 62.7m/s의 풍압력 조건에도 견딜 수 있는 철탑부착 고정형 폴리머 점퍼지지 애자장치를 개발하게 되었다.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.29-36
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• 2004

The wind and wind-induced dynamic wind pressures fluctuate irregularly according to time and space. In this study, the proper orthogonal decomposition(POD) technique is applied to wind pressures acting on a tall tower model, and the following results are found: the along-wind and across-wind forces can be reconstructed by only four dominant POD modes, and the reconstructed errors are 4.71% and 22%, respectively for across-wind and along-wind directions. The physical meanings for dominant modes are also presented in the paper. The POD analysis can compress complex wind pressure data only by a few dominant modes and interpret spatio-temporal characteristics of wind pressure by novel way while existing statistical methods do not have such benefits.