• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.1
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• pp.71-78
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• 2015

The reliable sloshing assessment methods for LNG CCS(cargo containment system) are important to satisfy the structural strength of the systems. Multiphase fluid flow of LNG and Gas Compressibility may have a large effect on excited pressures and structural response. Impinging jet model has been introduced to simulate the impact of the LNG sloshing and analyze structural response of LNG CCS as a practical FSI(fluid structure interaction) method. The practical method based on fluid structure interaction analysis is employed in order to evaluate the structural strength in actual scale for Mark III CCS. The numerical model is based on an Euler model that employs the CVFEM(control volume based finite element method). It includes the particle motion of gas to simulate not only the interphase interaction between LNG liquid and gas and the impact load on the LNG insulation box. The analysis results by proposed method are evaluated and discussed for an effectiveness of FSI analysis method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.145-154
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• 2013

HNS, including crude oil and products, shipments have increased. The risk analysis of HNS has assumed the importance, especially in maritime transportation area. There are various forms and kinds of HNS and the consequences of an accident are serious. In order to provide practical measures for preventing accidents, this study analyses the potential risks of HNS on maritime transportation accidents at domestic sea by using Event Tree Analysis. This study carries out risk assessment with F-N curve and risk matrix focusing on liquid cargo carriers (Oil and Products Tanker, Chemical Tanker, LPG/LNG Tanker, etc.). Explosion and sinking, suffocation indicate high consequence when on collision represent high probability. Improving human errors should be the main factor to mitigate risk on human lives.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.352-359
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• 2018

As a fuel for ship propulsion, liquefied natural gas (LNG) is currently considered a proven and reasonable solution for meeting the IMO emission regulations, with gas engines for the LNG-fueled ship covering a broad range of power outputs. For an LNG-fueled ship, the LNG bunkering process is different from the HFO bunkering process, in the sense that the cryogenic liquid transfer generates a considerable amount of boil-off gas (BOG). This study investigated the effect of the temperature difference on boil-off gas (BOG) production during ship-to-ship (STS) LNG bunkering to the receiving tank of the LNG-fueled ship. A concept design was resumed for the cargo/fuel tanks in the LNG bunkering vessel and the receiving vessel, as well as for LNG handling systems. Subsequently, the storage tank capacities of the LNG were $4,500m^3$ for the bunkering vessel and $700m^3$ for the receiving vessel. Process dynamic simulations by Aspen HYSYS were performed under several bunkering scenarios, which demonstrated that the boil-off gas and resulting pressure buildup in the receiving vessel were mainly determined by the temperature difference between bunkering and the receiving tank, pressure of the receiving tank, and amount of remaining LNG.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.3
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• pp.246-253
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• 2014

Liquid natural gas is stored and transported inside cargo tank which is made of specially designed cryogenic materials such as 9% Ni steel, Al5083-O alloy and SUS304 and so on. The materials have to keep excellent ductile characteristics under the cryogenic environment, down to -163oC, in order to avoid the catastrophic sudden brittle fracture during the operation condition. High manganese steel is considered to be the promising alternative material that can replace the commonly used materials mentioned above owing to its cost effectiveness. In line with this industrial need, the mechanical properties of the high manganese steel under both room and cryogenic environment were investigated in this study focused on its tensile and fatigue behavior. In terms of the tensile strength, the ultimate tensile strength of the base material of the high manganese steel was comparable to the existing cryogenic materials, but it turned out to be undermatched one when welding is involved in. The fatigue strength of the high manganese steel under room temperature was as good as other cryogenic materials, but under cryogenic environment, slightly less than others though better than Al 5083-O alloy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.512-519
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• 2015

A historical tragic disaster happened by capsizing the passenger ship Sewol at South Western Sea of Korea in 16, April 2014. The ship which left Incheon harbour to bound for Jeju port passed Maengol strait and reached to approach of Byung Pung island, and then capsized and sank with a sudden inclination to the portside in the mean time of starboard the helm. In this time, the ship which has very poor stability without sufficient ballast waters and with over loading cargo listed port side caused by the centrifugal force acting to the outside of turning. A lot of cargoes not fastened moved to the port side consequently, and the ship came to beam end to capsize and sank in the end. No crews including especially captain would offer their own duties in a such extremely urgent time, as a result, enormous number of victims broke out including a lot of student. In this report, author carried out some calculation on the factors which influenced on the stability of the ship, i.e. the ship's speed, the rudder angle, the weight of cargoes and distance of movement, the surface effect of liquid in the tank. We found out that the most causes of capsize were the poor stability with heavy cargoes and insufficient amount of ballast water against the rule, and the cargoes unfastened moved one side to add the inclination as well. Above all, the owner be blamable because of the illegally operating the ship without keeping the rule.

• Journal of Ocean Engineering and Technology
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• v.32 no.4
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• pp.272-278
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• 2018

Recently, the use of hazardous chemicals has been continuously increasing. Therefore, the international trade volume is growing and chemical accidents have increased. Nowadays, the safety awareness of the public has increased. As a result, the management and supervision of hazardous chemicals have been strengthened. However, the port policy of Korea has focused on increasing the volume of cargo through facility development. Thus, the port management of hazardous chemicals has been relatively neglected. For national economic growth and society, the port management of hazardous chemicals should be considered to efficiently ensure safety and economic growth. Therefore, this study assumed scenarios where hazardous materials were moved in a dangerous container, not only on appropriate wharfs but also in ports that were close to a big city. The BTX substances were selected among the toxic chemicals with large import and export volumes, and the risk distance and damage effects were predicted using various risk assessment programs. It is expected that this could be used to improve a port safety management system and could be utilized to determine the safety distance in case of an accident.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.465-471
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• 2003

A coastwise chemical tanker sailing at full speed has capsized during turning in calm water. In the previous paper, we investigated the reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and increased the vertical distance between the center of gravity of the ship and the center of lateral water drag.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.241-251
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• 2015

Recently, It became possible to transport freights and energy resources via Northern Sea Route(NSR) as global warming has been accelerated. As a result, all countries of the world and Korean local governments have had a struggle to take the advantageous position first in NSR development. However, this extreme competitions might have a negative effect on the national port industry and cause unnecessary social costs and economic losses. Therefore, the main target of this study is to find the most suitable port for NSR using AHP analysis. Most of the data was gained from previous literatures and public statistics and the weight of each factor was calculated by the result of expert survey. As a result, Busan port has the biggest competitiveness, followed by Yeosu Gwangyang, Ulsan and Incheon. From the result, this study suggested 3 possible scenarios. The first scenario specializing Busan port in NSR focuses more on developing the related businesses such as repair of ships, refueling, ship stores trade than attracting the more cargoes. the second is a strategy to make Ulsan port as a hub for energy resources, especially liquid cargo on NSR. the last is a mixed one to assign suitable roles to the ports according to their competitive capabilities.

• Journal of Korea Port Economic Association
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• v.35 no.2
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• pp.21-36
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• 2019

To ensure that Korea continues to grow, past governments have been consistent in following a policy of advancing into Russia, Mongolia, and Eurasia. The northern economy can expect to achieve synergistic growth because its economic structure complements that of Korea, which has high energy demand and industrial development. There is also an opportunity to accelerate the growth of the China-Russia-Mongolia economic corridor, which is based on Russia's Look East Policy, China's One Belt One Road, and the Mongolian Steppe Road initiative. The Korean government is pursuing a New Northern Policy to achieve the goal of economic cooperation and peace building with other nations, including North Korea; this policy succeeds the Northern Policy pursued by the previous government. As international economic cooperation requires transportation infrastructure, the demand for shipping, which offers more advantages than road and rail transportation, will increase; thus, it is necessary to prepare for it. Korea's port cities, which have a port that serves as the nodal point for maritime transportation, need to prepare for the New Northern Policy. In this paper, the long-term development of Seosan-Daesan port in the was planned and the North Korea's opening-op plan was considered in accordance with the New Northern Policy. Because international cooperation between the government and the provincial cities is required, cooperation with the Port Authority is needed, along with the proactive attitude of Seosan City, Chungcheongnam-do. The Seosan-Daesan port, which is the center of the liquid energy cargo center, can become the base of the New Northern Policy Region; further, the port can be an opportunity to establish its position as a peaceful economic hub on the west coast of Korea.