• Composites Research
• /
• v.36 no.6
• /
• pp.454-460
• /
• 2023

Recently, regulations on greenhouse gas emissions have been strengthened, and the International Maritime Organization (IMO) has been strengthening greenhouse gas regulations with a goal of net 'zero' emissions by 2050. In addition, in the shipbuilding/offshore sector, it is important to reduce operating costs, such as improving propulsion efficiency and lightening structures. In this regard, research is currently being conducted on topology optimization using 3D printed composite materials to satisfy structural lightness and high rigidity. In this study, three topology shapes (hexagonal, square, and triangular) were applied to the interior of a rudder, a ship structure, using 3D printed composite materials. Structural analysis was performed to determine the appropriate shape for the rudder. CFD analysis was performed at 10° intervals from 0° to 30° for each rudder angle under the condition of 8 knots, and the load conditions were set based on the CFD analysis results. As a result of the structural analysis considering the internal topology shape of the rudder, it was confirmed that the triangular, square, and hexagonal topology shapes have excellent performance. The rudder with a square topology shape weighs 78.5% of the rudder with a triangular shape, and the square topology shape is considered to superior in terms of weight reduction.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.2
• /
• pp.197-206
• /
• 2023

Recently, the international community, including the International Maritime Organization (IMO), has strengthened regulations on air pollution emissions of ships, and eco-friendly ships are actively being developed to reduce exhaust gas emissions. Among them, rotor sail (RS), a wind-assisted ship propulsion system, is attracting attention again. RS is a cylindrical device installed on the ship deck, that generates hydrodynamic lift using a magnus effect. This is a next generation eco-friendly auxiliary propulsion technology, and Enercon company, which developed RS-applied ships, announced that fuel savings of more than 30% are possible. In this study, optimal installation conditions such as RS spacing and arrangement type were selected when multiple RSs were installed on ships. AR=5.1, SR=1.0, and D_e/D was fixed at 2.0 according to the RS arrangement, and the wind direction was considered only for the unidirectional +y-axis. Regarding arrangement conditions, five conditions were set at 3D intervals in the +x-axis direction from 3D to 15D and five conditions in the +y-axis direction from 5D to 25D. C_L, C_D and aerodynamic efficiency (C_L/C_D) were compared according to the square(□) and diamond(◇) shape arrangements. Consequently, the effect of RS on the longitudinal distance was not significantly different. However, in the case of RS flow characteristics according to the transverse distance, the interaction effect of RS was the greatest when the two RSs almost matched the wind direction. In the case of the RS flow characteristics according to the arrangement, notably, when the wind blew in the forward (0°) direction, the diamond (◇) arrangement was least affected by the backward flow between RSs.

• Journal of Navigation and Port Research
• /
• v.29 no.5 s.101
• /
• pp.439-445
• /
• 2005

Recently, owing to the increasing demand on the simplification of arrival and departure procedures, IMO's (International Maritime Organization) Facilitation Committee (FAL) is carrying out the standardization project of arrival and departure formalities and clearance form. Also, many port authorities of developed countries are making active researches for the smooth flow and efficiency of the information inbound and outbound ships by way of simplifying their formalities or through electronic means. However, this standardization project cannot be done by one country but by mutual cooperation among related nations. And to carry out this task, the first thing to be done is to standardize the formalities and document form, and to integrate information. To this end, this study has reviewed the model cases of advanced ports of developed countries with regard to their simplification and standardization efforts. And also we have analyzed the formalities and clearance form of the three countries Korea, China, and Japan. And then for the solution of common problems of three countries, this paper has suggested an ebXML-based Global Port B2B framework. Through this framework, we can reuse and automate the necessary information on the arrival and departure of ships, consequently realizing simplification, and laying a foundation for the introduction of e-commerce to the port industry.

• Proceedings of KOSOMES biannual meeting
• /
• 2007.05a
• /
• pp.1-7
• /
• 2007

OPRC-HNS Protocol places the responsibility for having on-board a pollution incident emergency plan, notifying other States the incident facts in case of being affected by that incident, development of national contingency plan, international co-operation in pollution response, research and development, technical co-operation, promotion of bilateral and multilateral co-operation in preparedness and response, providing of information service, promotion of education and training, providing of technical services and technical assistance, etc. on parties to pursue their goals. After joining OPRC-HNS protocol, the government is required to inspect current status of matters related to HNS for its relevance on any laws. Additional items including establishment of component organization playing a role of managing response institution, manpower and resources, purchase response resource, development of response technique, and those also to enforce education and training to promote the party's duty. The facts described above drive up to analyze the benefits and burdens of relevant industry which appears in those procedure.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.7
• /
• pp.1238-1243
• /
• 2022

The International Maritime Organization is at the forefront of strengthening gas emission regulations for ships globally. The Korean government needs to apply measures to reduce emissions, such as setting a basic roadmap for greenhouse gas reduction. In addition, there is an urgent need to introduce a new efficient propulsion system that can reduce gas emissions. This includes applications to fishing vessels, which account for 90.6% of the greenhouse gas emissions from ships sailing along domestic coasts. In this study, an electric-combined propulsion system applicable to domestic coastal fishing vessels was developed. The target ship to which the electric-combined propulsion system could be applied was selected. A simulation system was constructed using MATLAB/Simulink to compare the expected fuel consumption when applying the developed complex electric propulsion system to the propulsion system mounted on the selected target fishing vessel. Through simulations, the differences in fuel consumption between the mechanical propulsion system and the electric hybrid propulsion system (both when charging and not charging the battery on land) were confirmed. The results show that fuel consumption can be decreased by approximately 13% and 16% when applying the electric-combined propulsion system.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.19 no.1
• /
• pp.1-6
• /
• 2016

Ballast water in ship operation is essential for a safe voyage. However ballast water can contain unwanted organisms that are the cause of disturbing the ecosystem by the transfer of potential invasive species. To prevent the destruction of the environment, the International Convention for the Control and Management of Ship's Ballast Water and Sediments(BWM Convention) was adopted in 2004. BWMS (Ballast Water Management System) has been developed to prevent the transportation of organisms to another region in order to fulfill the requirements IMO (International Maritime Organization) regulations. Nowadays there are about 50 approved Ballast Water Management Systems of various types globally. The most common BWMS types are UV (Ultra Violet), Electrolysis and Ozone. Among these types there are many difficulties in determining the optimum type of BWMS which can be suitable for the user and designer's requirements. The main objective of this research is to select the best BWMS type by using AHP. To apply AHP, the most important criteria for the BWMS development are derived by users and designers. From our results, we can give a guide BWMS type to the developers of BWMS.

• Journal of Environmental Science International
• /
• v.24 no.11
• /
• pp.1485-1491
• /
• 2015

There are two treatment processes that are currently applied to ships are the biological treatment process using the activated sludge and the electrochemical treatment. However, neither of them are able to remove both nitrogen and phosphorus due to their limited ability to remove organic matters, which are main causes of the red tide. This study was conducted to identify the characteristics of nitrogen removal factors from manure wastewater by replacing the final settling tank in SBR (Sequencing Batch Reactor) process and applying immersion type hollow fiber membrane. SBR process is known to have an advantage of the least land requirement in special environment such as in ship and the immersion type hollow fiber membrane is more stable in water quality change. As the result, the average in the cases of DO (Dissolved Oxygen) is 2.9(0. 6~3.9) mg/L which was determined to be the denitrifying microorganism activity in anaerobic conditions. The average in the cases of ORP (Oxidation Reduction Potential) is 98.4~237.3 mV which was determined to be the termination of nitrification since the inflection point was formed on the ORP curve due to decrease in the stirring treatment after the aeration, same as in the cases of DO. Little or no variation in the pH was determined to have positive effect on the nitrification. T-N (Total Nitrigen) removal efficiencies of the finally treated water were 71.4%, 72.3% and 66.5% in relatively average figures, thus was not a distinct prominence. In being applied in ships in the future, the operating conditions and structure improvements are deemed necessary since the MEPC (Marine Environment Protection Committee). 227(64) ship sewage nitrogen is less than the standard of 20 Qi/Qe mg/L or the removal rate of 70%.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.785-795
• /
• 2018

The International Maritime Organization (IMO) has recognized the risk of hull fouling and announced '2011 Guidelines for the control and management of ship's biofouling to minimize the transfer of invasive aquatic species'and is planning international regulations to enforce them in the future. In this study, to effectively respond to future international regulation, we introduce the case of leading countries related to management of hull fouling and also investigate environmental risk assessment techniques for in-water cleaning. Australia and New Zealand, the leading countries in hull fouling management, have established hull fouling regulations through biological and chemical risk assessment based on in-water cleaning scenarios. Most European countries without their government regulation have been found to perform in-water cleaning in accordance with the IMO's hull fouling regulations. In the Republic of Korea, there is no domestic law for hull fouling organisms, and only approximately 17 species of marine ecological disturbance organisms, are designated and managed under the Marine Ecosystem Law. Since in-water cleaning is accompanied by diffusion of alien species and release of chemical substances into aquatic environments, results from biological as well as chemical risk assessment are performed separately, and then evaluation of in-water cleaning permission is judged by combining these two results. Biological risk assessment created 40 codes of in-water cleaning scenarios, and calculated Risk Priority Number (RPN) scores based on key factors that affect intrusion of alien species during in-water cleaning. Chemical risk assessment was performed using the MAMPEC (Marine Antifoulant Model to Predict Environmental Concentrations), to determine PEC and PNEC values based on copper concentration released during in-water cleaning. Finally, if the PEC/PNEC ratio is >1, it means that chemical risk is high. Based on the assumption that the R/V EARDO ship performs in-water cleaning at Busan's Gamcheon Port, biological risk was estimated to be low due to the RPN value was <10,000, but the PEC/PNEC ratio was higher than 1, it was evaluated as impossible for in-water cleaning. Therefore, it will be necessary for the Republic of Korea to develop the in-water cleaning technology by referring to the case of leading countries and to establish domestic law of ship's hull fouling management, suitable for domestic harbors.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.9 no.4
• /
• pp.193-202
• /
• 2006

The Consultative Meeting of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and other matter, 1972 (London Convention 1972) has requested to International Maritime Organization (IMO) Marine Environmental Protection Committee to collaborate and help clarify a boundary issue between International Convention for the Prevention of Pollution from Shops, 1973 as modified by the Protocol of 1978 (MARPOL) and the London Convention concerning 'dumping' versus 'discharges' during normal operations of ships in 2004, and subsequently established a Joint London Convention/MEPC Correspondence Group. The Contracting Parties to London Convention expressed their environmental concerns on the broad interpretation of the "cargo-associated wastes" by the States, which could be discharged by ships under MARPOL. Regulatory regimes for the cargo residues appear to vary among states. Some countries require fur ships to discharge their cargo wastes into the port reception facility and IMO also recommends doing so. This paper examines the related current national and international legal texts for the regulation of disposal of wastes from ships in order to analyze the current global concern on the marine pollution associated with waste discharge during operations of ships. In particular, we attempt to evaluate the likely marine environmental consequences arising from the disposal of cargo residue using an hypothetical case for the coal cargo residue among bulk cargos in this paper, since location, magnitude and frequency of the discharge of coal cargo residues into the sea adjacent to Korean Peninsula are not readily available. The cargo residues may be discharged to the sea according to MARPOL 73/78; however, its marine environmental consequences can be significant depending upon the characteristics and amounts of wastes to be discharged. Also the public tolerance of the environmental consequences would be widely different among nations. Multilateral environmental agreements, in general, more strictly apply their rules if there are other options to disposal at sea, i.e. port reception facility in this case. Therefore, port reception facilities for the wastes generated by ships are recommended to be further constructed in major national ports in order to reduce the risk of environmental damages during the operations of ships.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.16 no.3
• /
• pp.202-210
• /
• 2013

As incomes increase, interest in ocean leisure picks up. As a result, a lot of research and developments on hull form design and production of planing boats, mostly used for ocean leisure, are needed. Analysis in researches on resistance of planing boats shows that resistance characteristic of planing boats is different from resistance characteristic of general boats because the former is fast, and its wetted surface is very small. Using Savitsky formula widely used in the calculation of effective horse power in shipbuildingyards, and propulsion system and engine manufacturers, this study calculated total resistance of a research planing boat. Then it analyzed the flow characteristics of the planing boat through theoretical analysis and wind tunnel experiment, and computed air resistance and lift force by changes of speed and trim angle. It also compared and analyzed result of theoretical analysis and experiment of the ratio of air resistance to total resistance under variations of velocity and trim angle. When the study is used to estimate more accurate effective horse power, it is expected to remedy abuses of unnecessarily installing high-powered engine. As nature disasters due to abnormal changes of weather increase, interest in greenhouse gas grows. International Maritime Organization (IMO) legislated Energy Efficiency Design Index (EEDI) and Energy Efficiency Operational Indicator (EEOI) to reduce ship greenhouse gas emissions. But this index will be applied to over 400 tons ships, small ships, emitting more greenhouse gases than larege ships per unit power, will dodge the regulations. Thus, this study indicated a problem by calculating greenhouse gas emissions of an ocean leisure planning boat (a small ship), and suggested the need for EEDI of small ships.