• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.201-202
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• 2021

Regulations on greenhouse gases emitted from ships in international shipping are being strengthened, and the greenhouse gas reduction target established by the International Maritime Organization is acting as a great challenge for shipping companies in terms of technical and operational aspects. The International Maritime Organization aims to reduce carbon intensity by 30% by 2030, 70% by 2050, and by 50% in terms of gross emissions compared to 2008. To realize this situation, the IMO adopted some short-term and mid-to-long-term measures and adopted technical measures such as the application of EEXI, an energy efficiency index, to existing ships from 2023, and the early application of EEDI phase 3 for some tpe of ships. In addition, reduction measures were introduced to reduce greenhouse gas in the operational aspect.

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.27-32
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• 2016

The reduction of $CO_2$ emissions has been a key target in the Marine Industry since the IMO's Marine Environment Protection Committee published its findings in 2009. The representative emission index is termed as the EEDI (Energy Efficiency Design Index) for the new ships. Among various flow control techniques ever proposed, the air lubrication method is the one of most promising one in terms of practical applicability. The present study examines the basic characteristics of the flat plate test with intention of applying the air lubrication technology to the reduction of the resistance of a ship. Image analysis technique is proposed as a tool to quantify the effectiveness of the air lubrication method.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.60-65
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• 2013

Now days, the demands of new type hull lines and optimum design in relation with the EEDI (Energy Efficiency Design Index) regulation and eco-friendly high efficiency vessel design are mandatory clauses in Euro financial crises era. Therefore, in correlation with the above, we tried to find the optimum results and revealed the alterations of supporting structure for liftable car deck latch on PCTC. Generally, PCTC (Pure Car & Truck Carrier) design has been performed by 2 pillar space model F. E analysis without vehicle loads on liftable car deck to evaluate the structural adaptability. So, we applied mentioned vehicle loads on pillar and side transverse web on model to compare with not applied model and performed the ultimate strength analysis of improved design for the safety evaluation.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.3
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• pp.135-145
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• 2018

This paper deals with the added resistance of a ship in waves using computational fluid dynamics (CFD). The ship added resistance is one of the key considerations in the design of energy-efficient ship. In this study, the added resistance of a LNG carrier in head waves is computed using a CFD code to consider the nonlinearity and the viscous effects. The unsteady Reynolds Averaged Navier-Stokes equation (RANS) is numerically solved and the volume of fluid (VOF) approach is used to simulate the free surface flows. The length of incident wave varies from half the ship length to twice the ship length. To investigate the nonlinearity effect, both the linear wave condition and the nonlinear wave condition are considered. The heave and pitch motions are calculated along with the added resistance, and the wave contours are obtained. Grid convergence test is conducted thoroughly to achieve the converged motion and resistance values. The calculated results are compared and validated with experimental data.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.10a
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• pp.39-40
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• 2011

The 62nd session of the MARINE Environment Protection Committee was held in London from 11 to 15 July 2011. Mandatory measures to reduce emissions of greenhouse gases (GHGs) from international shipping were adopted at the Committee. The amendment to MARPOL Annex VI includes a new chapter 4 to make mandatory the Energy Efficiency Design Index (EEDI) for new ships and the Ship Energy Efficiency Management Plan (SEEMP) for all ships. This first mandatory measures on energy efficiency will enter into force on 1 January 2013. This amendment to MARPOL Annex VI will significantly influences the vast majority of the international maritime community. This paper mainly discusses the main results of MEPC 62nd session including the recent Emission Control Area.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.577-587
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• 2017

The recent IMO MEPC regulation on EEDI, EEOI and increased fuel cost has worsened the financial condition of the small and medium sized passenger ferry companies, and it is situated to acquire the economic ships with a pretty high resistance performance. The purpose of this research is to develop a design method on the efficient gooseneck bulb for the middle-sized passenger ferry operated in the Far East Asian seas. The hull forms are designed by varying the gooseneck bulb parameters to find the changes on the resistance performance according to the shape of bulb. The numerical series tests are made to derive the regression equation for estimating the resistance through analyzing the data statistically. This equation is set as an objective function, and then using the optimization algorithm searches for the optimal combination of the design variables. After a hull form is designed corresponding to optimized parameters.

• Ocean Systems Engineering
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• v.5 no.2
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• pp.91-107
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• 2015

Ship hull optimization is categorized as a bound, multi variable, multi objective problem with nonlinear constraints. In such analysis, where the objective function representing the performance of the ship generally requires computationally involved hydrodynamic interaction evaluation methods, the objective functions are not smooth. Hence, the evolutionary techniques to attain the optimum hull forms is considered as the most practical strategy. In this study, a parametric ship hull form represented by B-Spline curves is optimized for multiple performance criteria using Genetic Algorithm. The methodology applied to automate the hull form generation, selection of optimization solvers and hydrodynamic parameter calculation for objective function and constraint definition are discussed here.

• TTA Journal
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• s.178
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• pp.8-13
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• 2018

최근 조선 및 해운경기가 급격히 위축되면서 해운사는 보다 많은 이익을 창출하기 위하여 첨단 ICT기술을 도입하여 최소 운항비 최대 이익 창출을 꾀하고 있다. IMO는 새로운 화두로서 자율운항선박이 운항 가능하도록 법적 개념 정립을 2020년까지 완료하도록 계획하고 있다. 산업계는 IMO의 NOx규제 Tier III(3.4 g/kWh, n<130), EEDI($CO_2$ 배출규제)의 Phase 1(Phase 0 대비 10%포인트 감소), Phase 2(Phase 1 대비 10%포인트 감소), EEOI 등 친환경선박 문제가 현안으로 대두되고 있는 상태에서 ICT와 결합하여 친환경 에코선박으로써 스마트선박이 문제를 해결하도록 기대하고 있다. 자율운항선박의 도입에 관해 많은 해운 전문가들 사이에 찬반의 의견이 분분하나 첨단 ICT를 도입하여 최소 운항비 최대 이익 창출을 추구하는 친환경 스마트선박의 도입에 대해서는 해운사 선주, 조선소 모두 앞을 다투고 있는 실정이다. 이러한 시점에서 세계 각 국가가 추진하고 있는 스마트자율운항선박의 연구와 기술 및 표준 동향과 우리나라가 추진하고 있는 연구와 산업계의 동향을 알아보고 새로운 전기를 맞이하게 될 글로벌 조선 산업의 미래를 조명해 보고자 한다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.582-587
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• 2016

연료효율에 대한 선주들의 요구와 그린쉽이라는 사회적 흐름에 맞춰 현재 연료 절감 장치에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 KVLCC2M의 반류개선 및 연료효율 증가를 위한 반원형 덕트의 변수 연구를 진행하였으며, 계산의 신뢰도를 검증하기 위해 서울대학교 선박저항성능 연구실에서 실시한 모형 시험결과와 비교하였다. 반원형 덕트의 크기와 길이방향 위치를 설계변수로 설정하여, 총 12가지 경우에 대한 CFD 계산을 시행하였으며, 계산 결과를 유동 정류를 통한 저항 감소와 반류 개선을 통한 프로펠러의 성능 개선 이라는 두 가지 기준으로 최적 조건을 선정하였다. 또한, 후처리를 통해 계산 결과를 추가적으로 분석하여 에너지 절감의 이론적인 배경을 찾았으며, 이를 바탕으로 반원형 덕트를 개선하여 부채꼴형 덕트를 새로이 설계하였다. 이에 대한 추가적인 계산 결과 최대 4%의 연료절감 효과를 최종 확인하였다.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.242-250
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• 2019

The speed and power performance of a ship is not only a guarantee issue between the ship owner and the ship-yard, but also is related with the Energy Efficiency Design Index (EEDI) regulation. Recently, International Organization for Standardization (ISO) published the procedure of the measurement and assessment for ship speed and power at sea trial. The results of speed and power performance measured in actual sea condition must inevitably include various uncertainty factors. In this study, the influence for systematic error of shaft power measurement system was examined using the Monte Carlo simulation. It is found that the expanded uncertainty of speed and power performance is approximately ${\pm}1.2%$ at the 95% confidence level(k=2) and most of the uncertainty factor is attributed to shaft torque measurement system.