• Journal of the Korean Society of Visualization
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• v.9 no.2
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• pp.54-60
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• 2011

This paper is a basic study on volatile organic compounds(VOC) recovery system in a crude oil carrier. VOC is easily evaporated in cargo tankers during loading and transportation of crude oil, causes serious environmental contamination and a huge economic loss. An ejector system is designed to mix VOC gas into crude oil flow to reduce VOC concentration. Detail two-phase flow inside the ejector is simulated using a commercial CFD code. To verify the numerical prediction, a scale-down experiment is conducted. Instead of crude oil and VOC, water and air are used as the working fluids. Flow characteristics and main parameters are obtained by two-phase flow visualization and PIV measurements. Air volume flow rate induced by the ejector is compared with respect to the volume flow rate of water using experimental and numerical results. Overall performance of the two-phase ejector predicted by the CFD simulation agrees well with that of the experiment.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.2
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• pp.104-110
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• 1997

Increase of marine transpotation in coastal area frequently yields oil spill accidents due to collision or grounding of oil tankers, which affects great deal of damages on ocean environments. Exact prediction of oil pollution area in time domain, which is called oil map, is very important for effective and efficient oil recovery and minimization of environmental damage. The prediction is carried out by considering the two distinct processes which are initial diffusion on the still water surface and advection due to tide, wind wave induced surface currents. In the present paper, only the initial diffusion is dealt with. Somewhat new simulation model and its numerical scheme are proposed to predict it. Simple diffusion experiment is also carried out to check the validity of the present method. Furthermore, some example simulations are performed for virtual oil spill accident. Quite realistic oil map including oil thickness distributions can be obtained by the present model.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.1
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• pp.17-23
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• 1982

The corrosion loss of the shell plates and the bulkead plates of the oil tankers, nationalities of which belong to korea are determined and analyzed. The thickness of the plates are determined by use of the ultrasonic thickness meters at the check points set along the fore and aft line and the perpendicular to it. Difference between the original thickness and the determined one are given as the corrosion loss at the present age. 1. On the shell plates (1) The total mean of the corrosion loss shows the greatest value on the load water line in every age classes of the vessels. (2) The total mean of the corrosion loss on the fore and aft line shows little difference, even though it is slightly greater at the fore part, in every age classes of the vessels. (3) The corrosion loss along the perpendicular grows greater in the order of upper bilge line, light water line, freeboard line and load water line at 16 ages of the vessels, and the loss changes in the order of light water line, upper bilge line, freeboard line and load water line at 20 ages of the vessels. (4) The total mean of the corrosion loss along the light water line and upper and lower water line shows the greatest value on the fore part. That along the freeboard line and the load water line shows the greatest value on the midship part and on the after part, respectively. 2. On the bulkhead plates (1) The total mean of the corrosion loss shows the greatest value on the top part at the every age classes of the vessels. (2)The corrosion loss along the perpendicular grows greater in the order of the lower, center and upper part at every age classes of the vessels. (3) The total mean of the corrosion loss at the top part grows greater in the order of the transverse bulkhead of the side oil tank, that of center oil tank, longitudinal bulkhead of center oil tank, and transverse bulkhead of side water tank at the 20 ages of the vessels.

• Journal of Navigation and Port Research
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• v.32 no.9
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• pp.711-716
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• 2008

Marine accidents related to the tug-barges are frequent recently, such as oil spill caused by collision between oil tankers and tug-barges. There are many causes of these accidents, but poor working condition of operators takes up a considerable part of most causes. That is, the danger of accidents caused by fatigue accumulation exists in tug-barges of less than 200 gross tonnage engaged on near-coastal voyages or short shipping, because of the long-distance navigational watch by only one master. This paper aims to deduce problems of human element part out of the plan of sqfe navigation, and to propose legal amendments for preventing marine accidents by tug-barges.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.4
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• pp.180-184
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• 2012

3-way ball valves have been mostly used for high temperature/high pressure valves using in petrochemical carriers and oil tankers, which requires high quality products with confidentiality and durability. As a larger disaster may be generated by leakage of oil or gas from valves, thus the present research applied a numerical analysis method with thermal-structural coupled field analysis and the performance test. The Max stress by parts was confirmed through thermal-structural coupled field analysis and develop the 3-way ball valve design, which is safe on operating condition. And its performance was verified by carrying out pressure test, leakage test and durability test for the manufactured 3-way ball valves with satisfying it's regulations.

• Journal of Navigation and Port Research
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• v.26 no.4
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• pp.407-417
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• 2002

Japanese oil companies have begun to set up a mutual support system to prepare for any large scale oil spillages due to the huge increase in size of tankers since 1973. In 1990, the Petroleum Association of Japan established the Oil Spill Response Department and has been conducting researches on management of oil spill combatting materials and the effective prevention of maritime oil disasters. Japan Coast Guard, in accordance with the regulations of the OPRC in 1995, formulated the national contingency plan and built a mutual-contact network among the related government institutions. Its Guard & Rescue Department. Disaster Prevention Section has been working for the maintenance of oil spill combatting materials and coordinating related work with private organizations. The Japanese government has been strengthening the maritime oil spillage management system since the Nakhodka wreck incident in 1997.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.598-605
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• 2010

The structural design of oil tankers and bulk carriers should be performed based on the Common Structural Rules(CSR) which were recently established by the International Association Classification Societies(IACS). At first, in the structural design viewpoint, the scantling and hullweight based on the CSR should be compared with those of existing rules, and then a minimum weight/cost design should be performed by considering the variation of the number of web and the material property. In this study, the optimum web space and material property will be proposed by performing a minimum weight/cost design of a large oil tanker, and the results will be compared with those of existing ship. The longitudinal members are determined by SeaTrust-Holdan developed by the Korean Register of Shipping(KR), and the transverse members are determined by NASTRAN and PULS.

• Journal of Ocean Engineering and Technology
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• v.38 no.1
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• pp.1-9
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• 2024

The vertical center of gravity (VCG) has a significant impact on the roll motion response of a surface ship, particularly oil tankers based on the oil level in the tanker after discharging oil at several stations or positional changes, such as changes in the superstructure and deck structure. This study examined the motion response of the Korea very large crude carrier 2 (KVLCC2) at various VCGs, especially roll motion when the VCG changed. The potential theory in the Ansys AQWA program was used as a numerical simulation method to calculate the motion response. On the other hand, the calculations obtained through potential theory overestimated the roll amplitudes during resonance and lacked precision. Therefore, roll damping is a necessary parameter that accounts for the viscosity effect by performing an experimental roll decay. The roll decay test estimated the roll damping coefficients for various VCGs using Froude's method. The motion response of the ship in regular waves was evaluated for various VCGs using the estimated roll-damping coefficients. In addition, the reliability of the numerical simulation in motion response was verified with those of the experiment method reported elsewhere. The simulation results showed that the responses of the surge, sway, heave, pitch, and yaw motion were not affected by changing the VCG, but the natural frequency and magnitude of the peak value of the roll motion response varied with the VCG.

• Journal of Environmental Policy
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• v.11 no.2
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• pp.17-54
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• 2012

This paper researched market responses for listed companies in several industries affected by the major oil spill accident off the coast of Taean, in December 7, 2007. The Taean accident triggered considerable concerns in people over the possibility of potential future regulation in shipbuilding and petroleum industries. However, the accident also provided an unexpected business opportunity for environmental clean-up industry and shipbuilding industry. The oil spill triggered the acceleration of the enactment of policies that require all new oil tankers to be constructed with double hull, which is interpreted as a good news for shipbuilding industry. Increased public pressure coupled with the prospect of tightened regulation is expected to decrease the market values of firms in the affected business fields. The stock prices of shipbuilding companies dropped after the incident but dramatically surged after the enactment of the policy in January 31, 2008. Our study also found that companies with more extensive prior environmental disclosure had less negative market reactions during the first sixteen days following the accident.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.149-156
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• 1992

An efficient preprocessor is developed for the finite element structural analysis of a ship's hull module. A hull module structure is divided into three groups for easy data handling : longitudinal members, transverse members, and transverse bulkheads. Based on the classification rules and design practices at shipyards, the preprocessor can create finite element nodes, elements, boundary conditions, and loadings automatically. By connecting the preprocessor with the ANSYS program, we can obtain the results of ship structureal analysis more efficiently. Applied to a typical double-hull oil tanker, the present preprocessor shows various advantages over conventional general-purpose preprocessors.