• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.105-109
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• 2007

Three methods of nozzle flow analysis, frozen-equilibrium, shifting-equilibrium and non-equilibrium approaches, were used to rocket nozzle flow, those were coupled with the methods of computational fluid dynamics code. For a design of high temperature rocket nozzle, chemical equilibrium analysis which shares the same numerical characteristics with frozen flow analysis can be an efficient design tool for predicting maximum thermodynamic performance of the nozzle. In this study, shifting-equilibrium flow analysis was carried out for the 30 $ton_f$-class KARl liquid rocket engine nozzle together with frozen flow. The performance evaluation based on the 30 $ton_f$-class KARl LRE nozzle flow analyses will provide an understanding of the thermochemical process in the nozzle and performances of nozzle.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.1-13
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• 2021

Effects of the nozzle wall angles on the supersonic flow field in a thrust optimized nozzle were numerically investigated. The combustor and operating condition of 30-tonf rocket engine was selected to study the optimum nozzle shape. The nozzle flow of combustion products was realized by the shifting equilibrium calculation for the propellant of kerosene-LOx. The change of nozzle wall angles induced different developing patterns of the internal and secondary shock wave. The optimum nozzle was obtained when the internal shock was in a specific position at the nozzle outlet. The nozzle wall angles of the optimum nozzle were very similar to those of the optimum nozzle which does not consider the shock wave.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.4
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• pp.63-72
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• 2013

A Mach 5 nozzle and a diffuser of the Scramjet Engine Test Facility (SETF) were made for a hydrocarbon-fueled scramjet engine. SETF, attached with a diffuser guide, started with a model of 60% blockage, though the model engine could not start by over expansion of the facility nozzle. The model was moved into the nozzle to escape the shock generated from the nozzle exit, both SETF and the engine could start. The pitot rake experiments (blockage of 2.3%) were done for measuring the core flow in the test section. From the pitot experiments, the core flow was expanded by an under expansion. It means that the core flow in the test section was related with a model blockage. SETF and the engine with a blockage of 33% work normally. From a series of experiments, SETF started with a normal shock efficiency of 58%, regardless of a blockage ratio.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.157-161
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• 2004

The colse type of engine system, in which the combustion gas after the gas-turbine with high temperature is supplied to the combustion chamber, was selected to increase the energy characteristics in making the rocket engine scheme which makes 1700kN thrust. The nozzle was designed with consideration of film cooling, nozzle efficiency, and the real state of cobmustion gas during the expansion in nozzle. The change of gas state and the composition of the gas through the nozzle was studied by the graphic, too.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.109-115
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• 2011

Development cases of space launch vehicle upper stage engine were studied. HM-7, Vinci, LE-5, RL10 engines are representative upper stage engines of Europe, Japan, and United States. It was realized that upper stage engines were developed with more than two engine test facilities and the development period was 5 to 8 years accompanied with 10~11 engines.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.395-399
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• 2009

Advanced afterburner used in the most modernized gas turbine has new designing paradigm to cope with reinforced power density. The most distinct change is the designing trend to integrate fuel injectors and flame holder in order to manage higher temperature of inlet air. F414 and F110-GE-132 engine adopted this methodology and installed a variable nozzle utilizing CMC(Ceramic Matric Composite) material and active cooling of nozzle flap with ejector nozzle in order to enhance the life cycle of engine components and an economical aspect. These technological trends can be utilized for an advanced ramjet engine and combined cycle engine like TBCC.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.50-55
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• 2004

Performance predictions of the propulsion system were conducted for a 900㎏ class Canard Rotor/Wing vehicle. The main components of the propulsion system are turbojet engine, exhaust ducts and nozzles. The internal flow of the duct was considered as one-dimensional, compressible and viscous flow. Adequate governing equations including centrifugal force effect were applied to the analysis of the duct flows. Results such as available power, available thrust, engine throttle, mass flow rates, rotor RPM and cruise nozzle area were presented for rotary-wing mode and transition mode.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.3
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• pp.241-247
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• 1997

터보 노즐에 유동하는 가스 에너지의 변화와 그위상의 조정에 의하여 디젤엔진의 성능 개선 가능성을 검토 하였다. 그리고 디젤기관의 각실린더와 터빈 노즐 면적과 가스의 유동에 대한 동기화를 실시함으로써 엔진 성능 또한 개선할 수 있었다.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.69-76
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• 2001

VCO nozzle is devised to minimize the HC emission and has been applied on some HSDI diesel engines. But it is not well reported whether VCO nozzle would be advantageous over SAC nozzle in a small HSDI diesel engine. In this paper it is presented that characteristics of VCO and SAC nozzle under common rail fuel injection system and their effects on the performance in a small HSDI diesel engine.