• Title/Summary/Keyword: 화물창

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An Effect of Surface Dashpot for KC-1 Basic Insulation System Under Sloshing Loads (슬로싱 하중을 받는 KC-1 단열시스템의 표면 완충 효과)

  • Jin, Kyo Kook;Yoon, Ihn Soo;Yang, Young Chul
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.3
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    • pp.193-199
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    • 2015
  • Sloshing of LNG cargo can cause high impact loads on the supporting and containing structures. This is particularly critical for membrane-type tanks since these will have flat surfaces and corner regions which can lead to increased peak pressures for sloshing impacts. The membrane-type containment system is much more flexible compared to the steel hull structure. As a result, fluid-structure interaction plays an important role in the structural analysis of the containment system under sloshing load. This study is based on the direct calculation method of applying sloshing loads to the KC-1 basic insulation system using finite element analysis. The structural analysis of KC-1 basic insulation system considers the dashpot as fluid-structure interaction between liquid cargo and the LNG containment system. The maximum stress of the polyurethane form for KC-1 insulation system is 1.5 times lower than one without dashpot.

Study on Hydroelastic Analysis of LNGC Cargo by Global-Local Analysis Technique (전역-국부 해석기법에 의한 LNG 운반선 화물창의 유탄성 해석에 관한 연구)

  • Park, Seong-Woo;Cho, Jin-Rae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.1
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    • pp.83-92
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    • 2007
  • There are many numerical methods to solve large-scale fluid-structure interaction(FSI) problems. However, these methods require very fine mesh to achieve the reasonable numerical accuracy and stability due to the concentrated and volatile hydrodynamic pressure caused by the liquid sloshing. Consequently, the numerical analysis targeting for the long-period time response with the desired numerical accuracy Is very highly time-consuming. The aim of this paper is to suggest a new method to analyze the hydroelastic behavior of the LNGC containment by using the global-local numerical approach. The reliability of the presented method is firstly examined, and then its efficiency is demonstrated by presenting that the long-period local responses of the LNGC containment are obtained with relatively short CPU time.

Structural and Vibrational Characteristics for the Scaffolding System of LNG Cargo Containment (LNG 화물창 비계 시스템의 구조해석 및 진동 특성)

  • Ryu, B.J.;Shin, G.B.;Nahm, Y.E.;Oh, B.J.;Baek, S.G.;Kim, H.S.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1197-1202
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    • 2007
  • The paper deals with the structural analysis and vibration test for the scaffolding system of LNG cargo containment. The eight-stories scaffolding system has telescopic area, working area, coner area and storage area in real system. In the structural analysis, the maximum displacement and stress of the each floor for the scaffolding system are investigated by finite element method. In the vibrational analysis, the natural frequencies and mode shapes for 8-stories scaffolding system of the LNG cargo containment are investigated. In order to compare theoretical natural frequencies with experimental ones, small size of 2-step scaffolding structure is used, and the theoretical results for natural frequency have a good agreement with experimental ones.

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Structural and Vibration Characteristics for the Scaffolding System of LNG Cargo Containment (LNG 화물창 비계 시스템의 구조해석 및 진동 특성)

  • Oh, B.J.;Ryu, B.J.;Lee, Y.S.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.546-554
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    • 2010
  • The paper deals with the structural analysis and vibration test for the scaffolding system of LNG cargo containment. The eight-stories scaffolding system has telescopic area, working area, coner area and storage area in real system. In the structural analysis, the maximum displacement and stress of the each floor for the scaffolding system are investigated by finite element method. In the vibrational analysis, the natural frequencies and mode shapes for 8-stories scaffolding system of the LNG cargo containment are investigated. In order to compare theoretical natural frequencies with experimental ones, small size of 2-step scaffolding structure is used, and the theoretical results for natural frequency have a good agreement with experimental ones.

A Study on the Condensation Prevention of Bulk Carrier (화물선의 결로 방지에 대한 연구)

  • Oh, Sae-Gin;Kim, Won-Ouk;Kim, Seung-Hwan;Lee, Seung-Geun;Kim, Jong-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.4
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    • pp.429-434
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    • 2011
  • Bulk cargo loaded into ship can be damaged by various kinds reasons. This paper aims to analyze about cargo damage of coil carrier ship due to condensation. Condensation is the formation of liquid drops of water from water vapor. Condensation consists of small drops of water which form when warm water vapour or steam touches a cold surface such as a window. In general, condensation have occurred by temperature difference at large building and ship's tank. It is phenomenon that can occur often to oceangoing vessel moving temperature difference places in similar time. This paper proposes a new method using dehumidification device and fan heater to prevent bulk cargo damage of coil carrier ship from condensation.

Heat Flux Calculation for Thermal Equilibrium of Cofferdam in a LNG Carrier (LNG선 Heating Coil의 설계를 위한 Cofferdam내 열정산)

  • Joo-Ho Heo;Young-Bum Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.35 no.1
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    • pp.98-106
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    • 1998
  • This paper shows the temperature distribution of double hull compartment and of cofferdam in a large LNG Carrier. In LNG Carrier, due to the lower cargo temperature($-163^{\circ}C$), structures are forced to lose their strength if additional heat is not supplied. So it is very important to estimate the temperature distribution and the heat flux needed to maintain the structure properly. The temperature of each compartment is obtained using 2-dimensional model analysis and compared with 3-dimensional results. And also this paper gives preliminary estimation of pipe length to supply necessary heat flux in bare pipe and finned pipe.

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A Study of Fatigue Strength Assessment for Hopper Knuckle of Bulk Carrier According to Joint Shape Change (산적화물선 호퍼 너클 이음부의 형상 변화에 따른 피로강도평가에 관한 연구)

  • Shim, Chun-Sik;Lee, Hoon-Dong;Hwang, Jeong-Hyun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2009.04a
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    • pp.335-338
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    • 2009
  • 일반적으로 비중이 큰 철광석이나 석탄 등을 운반하는 선박화물선의 호퍼 너클 이음부는 여러 판이 용접되어 복잡한 형상을 가지고 있어 응력이 집중되어지므로 피로강도평가 시 많은 문제점이 노출되는 구간이다. 이번 연구에서는 기존 sloping 방식의 호퍼 너클 이음 부를 갖는 180k 산적화물선 표준 모델과 제안 되어진 round 방식의 호퍼 너클 이음 부를 갖는 산적화물선에 대하여 구조강도평가와 피로강도평가를 수행하였다. 이때 합리적인 비교를 위하여 제안되어진 모델은 기존의 표준 모델의 화물창과 발라스트창의용적이 일치하도록 제안하였다. 또한 CSR을 기반으로 한 하중들에 대하여 허용응력과 25년 피로수명을 만족하도록 구조부재를 결정하였으며 피로강도평가 결과를 바탕으로 호퍼 너클부의 변화에 따른 선각 중량과 상대 건조 비 개념을 이용하여 보다 효율적인 구조를 제시 하였다.

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