• Journal of Ocean Engineering and Technology
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• v.37 no.6
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• pp.282-282
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• 2023

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.419-427
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• 2015

Recently Energy Saving Device has been developed actively due to the regulation of the EEDI. This Energy Saving Device which is newly developed is integrated duct and stator. This paper verified performance of the Energy Saving Device through CFD. The experimentation to find the best pitch angle of each blade of the stator designed has been conducted. The angle of incidence of the duct has been obtained through the measurement of the wake. The experimentation has been carried out with and without Energy Saving Device. The efficiency increase was through these two experiments.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.352-360
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• 2019

International Maritime Organization (IMO) regulates an emission of greenhouse gases by creating an Energy Efficiency Design Index (EEDI) to reduce environmental pollution. In propulsion system field, studies are under way on Energy Saving Device (ESD), which can improve propulsion efficiency with the propeller, to reduce the EEDI. Among the studies, the study of Pre-Swirl Stator (PSS) has been actively conducted from long time ago. Recently the variable pith angle type pre-swirl stator has been studied to improve the propulsion efficiency in non-uniform flow fields of the Stern. However, for traditional design methods, no specific design method has been established on the blade or location of radius. In this study, proper design method is proposed for each blade or location for radius according to hydrodynamic pitch angle.

• Journal of Ocean Engineering and Technology
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• v.35 no.4
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• pp.247-256
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• 2021

In order to minimize carbon emissions and greenhouse gas, the Energy Efficiency Design Index (EEDI) has become a major factor to be considered in recent years in a ship's design and operation phases. Energy-Saving Devices (ESDs) improve the EEDI of a vessel and make them environmentally friendly. In this research, the performance of an equalizing duct-type ESD installed upstream of a Korea Research Institute of Ships & Ocean Engineering (KRISO) Container Ship (KCS) model's propeller was investigated by computational fluid dynamics (CFD). Open-source CFD libraries, OpenFOAM, were used for computational analysis of the KCS with and without the ESD to verify the performance improvement. The flow field near the stern region and propulsive coefficients were considered for comparison. The results showed a considerable improvement when an ESD was used on the model. Using different sizes of the duct, the performance of the ESD was also compared. It was observed that with an increased duct size, the propulsive performance was improved.

• Journal of Korea Trade
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• v.26 no.1
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• pp.113-125
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• 2022

Purpose - The primary purpose of this study is to verify whether the target set out by the International Maritime Organization (IMO) for reducing carbon emissions from ships can be achieved by quantitatively analyzing the trends in technological advances of fuel oil consumption in the container shipping market. To achieve this purpose, several scenarios are designed considering various options such as eco-friendly fuels, low-speed operation, and the growth in ship size. Design/methodology - The vessel size and speed used in prior studies are utilized to estimate the fuel oil consumption of container ships and the pace of technological progress and Energy Efficiency Design Index (EEDI) regulations are added. A database of 5,260 container ships, as of 2019, is used for multiple linear regression and quantile regression analyses. Findings - The fuel oil consumption of vessels is predominantly affected by their speed, followed by their size, and the annual technological progress is estimated to be 0.57%. As the quantile increases, the influence of ship size and pace of technological progress increases, while the influence of speed and coefficient of EEDI variables decreases. Originality/value - The conservative estimation of carbon emission drawn by a quantitative analysis of the technological progress concerning the fuel efficiency of container vessels shows that it is not possible to achieve IMO targets. Therefore, innovative efforts beyond the current scope of technological progress are required.

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

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.92-92
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• 2017

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.576-582
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• 2016

To cope with international regulations, such as Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and so forth, and to enforce limitations on $CO_2$ emissions, green-ship technology to lower fuel consumption has been actively researched, and the development of an energy-saving device (ESD) is being pursued. In order to design an ESD for small and medium-sized domestic vessels, an analysis on flow characteristics has been performed in the present study. Through a model test and numerical analyses, the characteristics of flow around the stern bilge and bulb have been compared to improve wake quality and resistance performance. As a result of these comparisons and analyses, a vertical plate has been adopted,, as a new ESD. Design criteria for the proposed ESD are also suggested. By applying this new ESD, it is expected that the total resistance and average nominal wake can be reduced by 3.04 % and 18.8 %, respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.205-211
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• 2014

Interests on energy saving devices (ESDs) have been increased with the concern of the energy efficiency design index (EEDI) developed by the international maritime organization (IMO). To study the influence of ESDs, KVLCC2 with energy saving pre-swirl stator (PSS) was selected. To validate the computations, computed nominal wake of the model scale ship was compared with the experimental data, and the numerical uncertainty assessment was done for the full scale ship computations. The PSS changed rotational flow, which was assistant to the propeller thrust for the model and full scale ships. Performances of the full scale ships were predicted by ITTC methods, and new prediction method was proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.44-49
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• 2020

Recently, one of the major issues of shipbuilding and marine is the reduction of air and marine pollution emission to ships. In response, the International Maritime Organization (IMO) has concluded an international convention (MARPOL) to prevent pollution from ships. A Annex Six of The Convention restricts and regulates air and marine pollution of ship from exhausting gases. To this end, it is required to apply EEDI (Energy Efficiency Design Indicators) to the construction of new ships, and to minimize the emission of environmental pollutants by recommending the application of EEOI (Energy Efficiency Operation Indicators) to operational ships. Therefore, in this study, we propose to calculate the grade of operating efficiency (EG) of ships based on actual operational data for transport ships and to provide energy-efficient optimal path search information through analysis of marine environment data.