• Proceedings of the KWS Conference
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• v.43
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• pp.213-215
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• 2004

Water jet propulsion system has high efficiency on middle to high speed, and it provides better safety than conventional screw propeller because it has not projected propeller and rudder. So many leisure boat and high-speed ferries use this propulsion system. We developed water-jet propulsion unit for small planning boat, and launched that in the boat, after that we tested water-jet unit in the lake. As a result, we certify heat dissipation at the bearing housing and reverse duct's shape for neutral position are important at the design, and alignment water-jet unit and keel line are important at the launching, and ship's resistance performance and jet's propulsion performance also are needed to consideration.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1992.11a
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• pp.35-38
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• 1992

The feasibility of magnetohydrodynamic (MHD) Ship propulsion using superconduction magnets is reviewed in light of recent advances in high-temperature superconducting. The propulsion using a screw propeller in the noise reduction has it's own limitation. The epochal noiseless MHD propulsion method which does not have this disadvantage is studying nowadays. The subject of a marine MHD as propulsion has been examined before and was found to be interesting because of relatively low magnetic flux densities. It is demonstrated that the MHD propulsion is technically interesting with high magnetic flux density. The development of large-scale magnets using the high-temperature superconductors now under development could make it practical to construct submersibles for high-speed and silent operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.426-430
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• 2005

The COMS(Communication, Ocean and Meteorological Satellite) is the first developed three-axis stabilization multi-function satellite on geostationary earth orbit(GEO) in korea, presently scheduled to be launched in 2008. The COMS propulsion system provides the thrust and torque required for the insertion into GEO, attitude and orbit control/adjustment of spacecraft. In this paper, system design of propulsion system, basic functions and design requirement of components are described.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.797-800
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• 2011

For the space launch vehicle, propulsion system is the most important subsystem among others. For the evaluation of development level for rocket engine, integrated system test performed in appropriate facility is needed. In this study, test article and major parameters for certifying the propulsion system of launch vehicle were reviewed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.31-34
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• 2003

To trace the working point of pressure-fed rocket propulsion system, direct analogy model was suggested, by which propellant mass flow rate and combustion chamber pressure were calculated from propellant tank pressures, levels and flight acceleration. In this paper, the analysis of KSR-III flight test results was taken by example, and it can be described that working point transition tendency of pressure-fed rocket propulsion system can be calculated by this direct analogy model.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.1
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• pp.75-82
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• 2014

In vibration analysis of ships, the principle aim is to determine the natural frequencies and excitation frequencies, and use this information to avoid resonances and vibration damage. The simplest method is to prevent resonance conditions, which is effective as long as the natural frequencies and excitation frequencies can be regarded as independent from environmental conditions. For ships that use electric propulsion systems, the sources of vibration are reduced compared with those caused by a diesel engine or other combustion-based propulsion systems. However, the frequency spectrum of these vibrations may be different; therefore, to understand the characteristics of the electric propulsion, we also should investigate how the ship responds to these vibrations. We focused on a 1,000-ton deadweight (DWT) ocean-research vessel using an electric propulsion system and analyzed the response to vibration.

• Journal of Mechanical Science and Technology
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• v.18 no.5
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• pp.847-856
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• 2004

Heaters for the spacecraft propulsion system are sized to prevent propellant from catastrophic freezing. For this purpose, thermal mathematical model (TMM) of the propulsion system is developed. Calculation output is compared with the results obtained from thermal vacuum test in order to check the validity of TMM. Despite a little discrepancy between the two types of results, both of them are qualitatively compatible. It is concluded that the propulsion system heaters are correctly sized and TMM can be used as a thermal design tool for the spacecraft propulsion system.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.2
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• pp.1-17
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• 1994

잠수함추진방식은 크게 원자력 추진과 재래식 추진으로 나눌수 있다. 최근에는 재래식 추진방식과 하이브리드 개념으로 운용될 수 있는 AIP(Air Independent Propulsion)방식도 활발히 연구되고 있다. AIP추진으로는 폐회로 디젤기관추진(Closed Cycle Diesel Engine Propulsion), 연료전지추진(Fuel Cell Propulsion), 스터링기관추진(Stirling Engine Propulsion) 및 폐회로터빈추진(Closed Cycle Turbin Propulsion) 등이 있다. 이러한 잠수함 추진체계에 대해 앞으로 크게 세부분으로 나누어 그 현황과 발전추세를 살펴보고자 한다. 즉, 초기의 순수전기추진방식으로 불리는 재래식 추진체계, 재래식 추진방식의 한계를 극복하기 위해 최근 활발히 연구되고 있는 외기와 무관한 추진장치인 폐회로 추진체계, 그리고 궁극적으로는 에너지의 문제로 귀착되어 거의 무한대의 에너지원을 가지고 있는 원자력 추진체계로 구분하여 그 현황과 발전내용을 살펴 봄으로써 잠수함추진체계의 국내연구 개발방향정립에 조금이나마 보탬이 되었으면 합니다. 또한 차세대 추진장치로 불리는 전자유체 추진방식에 대해서는 한국박용기관 학회지 1993년 4월호 "박용전자유체(MHD) 추진장치"를 참조하시기 바랍니다.조하시기 바랍니다.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.41-44
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• 2007

Korea Aerospace Research Institute (KARI) has jointly developed a bipropellant propulsion system for Communication, Ocean and Meteorological Satellite (COMS) with EADS Astrium in UK. The technology relevant to a bipropellant propulsion system is quite new one in Korea, which is transferred for the first time, with development of COMS propulsion system. It hasn't ever attempted before, and hasn't got any general idea itself as well, in Korea. The COMS Chemical Propulsion System (CPS) is designed to perform both the orbital injection function, to take the spacecraft from transfer orbit to Geostationary Earth Orbit (GEO), and all on-station propulsive functions throughout the lifetime of the satellite. All station keeping manoeuvres are performed using the CPS. The design, manufacture and testing of COMS CPS are addressed in this paper. Feasibility of COMS CPS applicable to the other advanced mission is investigated as well.

• Journal of the Korean Society of Systems Engineering
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• v.1 no.1
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• pp.61-66
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• 2005

In executing the large scale national project, such as development of space launch vehicle, it is most important to guarantee the technological reliability. However the reliability analysis of launch vehicle is different from other mass product goods because of the limitation of budget and number of tests. In this study, the reliability analysis technique of the propulsion system, which is one of the major sub-systems of launch vehicle is illustrated and applied to the liquid rocket engine of KSR-III.