• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.83-89
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• 2011

A design plan was proposed for determining combustor configuration of regenerative- cooled liquid rocket engine in the process of preliminary design. Rocket performance and regenerative cooling results were calculated using the properties of combustion gas estimated in CEA. For required thrust, chamber pressure, atmosphere pressure and propellant mixture ratio the mass flow rate of propellants and combustor performance were predicted by one-dimensional and experimental correlations. Finally, determinable plan for the contour of combustor were presented through Rao nozzle design method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.37-42
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• 2010

A design plan was proposed for determining combustor configuration of regenerative- cooled liquid rocket engine in the process of preliminary design. Rocket performance and regenerative cooling results were calculated using the properties of combustion gas estimated in CEA. For required thrust, chamber pressure, atmosphere pressure and propellant mixture ratio the mass flow rate of propellants and combustor performance were predicted using one-dimensional and experimental equations. Finally, determinable plan for contour of combustor were presented through Rao nozzle design method.

• Bulletin of the Society of Naval Architects of Korea
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• v.41 no.2
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• pp.86-93
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• 2004

일반적으로 액화암모니아, LPG, 메탄, 부탄 등을 운송하는 가스운반선은 가스를 비등점 이하의 온도로 낮춰서 액화하여 운송하는 선박으로, 가스의 비등점이 -3$0^{\circ}C$에서 -4$0^{\circ}C$ 내외의 저온이므로 대기압 상태에서는 냉각되어 액화상태 약 -48$^{\circ}C$ 유지로 화물탱크에 저장 운반되어야 하는 여러 가지 제약조건이 따른다. 이러한 가스를 보관하는 탱크는 주로 저온에 강한 니켈강을 쓰게 되며 완벽한 고도의 용접기술을 필요로 하고, 저온상태의 화물 저장 운송을 위해서는 대형 냉동기와 보온설비도 필요하다. (중략)

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.395-402
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• 2010

Baffle injectors are protruded into the combustion chamber and form an anti-pulsating baffle to prevent high-frequency combustion instabilities in transverse modes. Being exposed to a high heat-flux environment, the baffle injector has self-cooling passages through which kerosene is convected and heated. The baffle injector with 20 spiral cooling channels has been developed and successfully applied to 30 $ton_f$-class combustors without any performance loss due to an additional cooling. In this work, numerical analysis of conjugate heat transfer in baffle injectors with various cooling channel designs has been performed in order to reduce the fabrication cost which would be considerably increased for the 75 $ton_f$-class combustor. Prior to the application to a full-scale combustor, the thermal durability of the modified design has been verified through the subscale hot-firing tests.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.139-149
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• 2011

The combustion chamber and nozzle of a liquid rocket engine need thermal protection against the high temperature combustion gas. The nozzle extension of a high-altitude engine also has to be compatible with high temperature environment and several kinds of cooling methods including gas film cooling, ablative cooling and radiative cooling are used. Especially for an upper-stage nozzle extension having a large expansion ratio, the weight impact on the launcher performance is crucial and it necessitated the development of light-weight refractory material. The present survey on the nozzle extension materials employed in the liquid rocket engines of USA, Russia and European Union has revealed a trend that the heavier metals like stainless steels and titanium alloys are being substituted with light weight carbon fiber or ceramic matrix composite materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.1046-1052
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which was operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreased the thermal load and strain of the cooling channel structure. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.802-807
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was also conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which is operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion data were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreases the thermal load and strain of the cooling channel. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.1
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• pp.54-65
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• 1994

Performance of naturally circulating cooling system of $SF_6$ gas charged transformer was simulated and the variations of gas flow rate, maximum coil temperature, gas temperature and cooling air temperature were investigated with respect to the height of radiator, interplates distance and heat generation rate at core. The results show that the height of radiator most significantly affects the performance of natural circulating cooling system of transformer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.34-40
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• 2006

For a cooling performance research of the combustor operated in a extreme environment of a high temperature and high pressure, we accomplished a cooling performance analysis. Generally a heat transfer characteristic in cooling passage is known well experimentally and theoretically, however heat flux in the combustion chamber isn't. In this study, fluid flow combined with heat transfer and thermal structural analysis is accomplished about a combustor nozzle. We tried to analyze the cooling performance with a heat transfer characteristic of a gas and coolant side in the view point of quantity on the mass flow rate to be supplied to the cooling channel. And finally, evaluation on the thermal and structural safety of nozzle wall material was accomplished.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.147-150
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• 2007

In this study, cooling characteristics of combustion gas were investigated by injecting liquid nitrogen into liquid rocket combustion chamber. A injection ring of liquid nitrogen was installed between a combustion chamber and a mixing chamber which was designed for mixing of combustion gas and nitrogen. At first, a ignition test of liquid rocket engine was conducted to verify a stable combustion process and 10 second combustion tests were successfully conducted. The results showed that combustion gas of LRE could be cooled by using liquid nitrogen.