• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.933-940
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• 2017

Draught and trim conditions are highly related to the loading condition of a vessel and are important factors in predicting ship manoeuverability. This paper estimates hydrodynamic coefficients from sea trial measurements with three different trim and draught conditions. A mathematical optimization method for system identification was applied to estimate the forces and moment acting on the hull. Also, fast time simulation software based on the Rheinmetall Defense model was applied to the whole estimation process, and a 4,500 Twenty-foot Equivalent Unit (TEU) class container carrier was chosen to collect sets of measurement data. Simulation results using both optimized coefficients and newly-calculated coefficients for validation agreed well with benchmark data. The results show mathematical optimization using sea measurement data enables hydrodynamic coefficients to be estimated more simply.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.453-459
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• 2020

A sea trial of the speed performance test is the one of the most important means of verifying a ship's performance, and the International Organization for Standardization established a standard for this test in 2015. Environmental disturbances such as wind and waves are always present under real sea conditions, however, so it is impossible to accurately estimate delivered horsepower under ideal conditions. These disruptive influences also make it difficult to evaluate the positive effect of recently developed energy-saving devices. In this study, uncertainty analysis of improved speed performance was carried out using Monte Carlo simulation to confirm the energy-saving efficiency of a ship equipped with an air-lubrication system. The findings showed the average power saving to be 3.2%, with the expanded uncertainty of ± 2.7% at a 95% confidence level (k=2).

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.405-413
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• 2005

본 연구에서는 3톤/일의 플라스틱 투입량을 기준으로 혼합폐플라스틱으로부터 대체연료유를 생산할 수 있는 소용량 중심의 폐플라스틱 유화설비를 설계 제작하였으며 장기간에 걸친 시운전을 통하여 유화설비의 운전성 평가에 대한 실증연구를 수행하였다. 대상 폐플라스틱으로는 플라스틱 재활용 업체에서 분리 선별된 폴리에틸렌과 폴리프로필렌 그리고 이들을 혼합한 폐플라스틱을 각각 적용하였으며 $400\sim420^{\circ}C$의 분해 운전온도에서 폐플라스틱의 종류에 따른 시운전 평가를 하였다. 본 실증연구로부터 폴리에틸렌의 경우에 있어서는 79%의 재생유 회수율을 그리고 폴리프로필렌의 경우에 있어서는 80%의 재생유 회수율을 각각 얻을 수 있었으며 플라스틱 종류별 안정적인 운전조건을 확보할 수 있었다. 또한 폐플라스틱 투입량에 대한 설계용량과 운전용량과의 비교로부터 약 40$\sim$50%의 설계오차가 발생한 것으로 평가되었으며 이는 유화설비의 설계를 위하여 사용된 혼합폐플라스틱의 부정확한 물성 값에 기인한 것으로 판단된다. 따라서 본 연구로부터 얻은 시운전결과를 바탕으로 설계인자들을 확립하는 과정이 반드시 필요할 것으로 판단된다.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.1
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• pp.53-60
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• 1999

Prior to sea trials, dock trials are usually carried out in order to check the main propulsion system and auxiliaries. At that time the motion of a ship is limited by mooring ropes. In Hyundai Heavy Industries, a simple equation is used to obtain propeller thrust which is used as an input data of mooring analysis. Recently the ship size and the engine power become larger. Therefore a careful analysis of the mooring condition is necessary in order to avoid possible accidents. In this study propeller thrust at deck trials is reviewed and examined through a series of model tests.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.69-75
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• 2016

This paper covers the result of construction and start-up tests of the KSLV(Korea Space Launch Vehicle)-II combustion chamber hot-firing test facility. This facility was constructed from 2012 to 2014. Start-up test of this facility began in the second half of 2014. Oxidizer cold flow test, fuel cold flow test and cooling water cold flow test were carried out as start-up test. Afterward, ignition test of combustion chamber was accomplished. The result of ignition test is applied to set up start-up sequence of KSLV-II combustion chamber and utilized as base line data for hot-firing test of low and normal design point.

• Nuclear industry
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• v.28 no.1 s.299
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• pp.66-75
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• 2008

• 전기의세계
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• v.62 no.6
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• pp.24-29
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• 2013

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.123-131
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• 2000

• Journal of the Korean Society for Railway
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• v.8 no.3 s.28
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• pp.45-53
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• 2005

• Electric Engineers Magazine
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• s.122
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• pp.46-55
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• 1992