• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.89-92
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• 2009

Because many research using concentrated hydrogen peroxide as propellant is studied, research for distillation method for domestic production of rocket grade hydrogen peroxide is needed. To distill hydrogen peroxide, vacuum distillation will be used because of heat decomposition of hydrogen peroxide. Distillation pressure is 30 torr which is determined by Raoult's law to distill under $40^{\circ}C$. Variable of distillation experiment is distillation temperature. And the comparison of distillation results was done by yield and operation time. In the result, generally, yield was lower and the water in receiver had higher concentration with shorter distillation time. And with similar time, when distillation temperature was higher, yield was lower and hydrogen peroxide became higher concentration.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.2
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• pp.44-53
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• 2003

A vertical hot-firing test facility was established to carry out the IPPT(Integrated Propulsion Performance Test) and SQT(Stage Qualification Test) of KSR-III(Korea Sounding Rocket-III). The components for actual launcher were mostly used, hence these tests were carried out under the condition of relatively lower safety margin. To perform hot-firing tests with the maximum safety, an engine emergency blockage system was investigated and applied. An emergency blockage system using combustion chamber pressures and acceleration signals was set up to monitor ignition delay and fail, flame out, propellant feeding status, unstable combustion and excessive structural vibration. With such a system, the test safety could be secured by rapid judgement and follow-up measures, which made IPPT and SQT be safely completed.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.31-36
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• 2007

Combustion performance characteristics of subscale high-pressure combustor were investigated at 70 bar combustion pressure. All tests were successfully performed without any damage on the combustor. The mixing characteristics and distribution pattern of the injectors were found to have considerable influence on the combustion performance. The characteristic velocity of the combustor was higher in the injector with internal mixing than that of external mixing and in the injector with smaller mass flowrate. The pressure fluctuations at the propellant manifolds and the combustion chamber were measured to be less than 3% of the mean combustion pressure to meet the combustion stability criterion and to prove stable combustion characteristics of the combustor.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.23-30
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• 2007

The effectiveness of a pogo suppression device (PSD) on the response of piping system simulating the propellant supply lines of the rocket engines was investigated experimentally by other researchers. In this study, the simplified analytical model was made, and the key parameters which are difficult to derive theoretically were identified in combination with the previous experimental work. In other words, the flow transient equations for a PSD system and the key parameters used to decide the instability of the system from the linearized transfer function including inertance, compliance, and resistance were derived. From the analysis, the values of key parameters could be determined from the experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1144-1147
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• 2017

It was reviewed about the pressure oscillation on the inlet of turbo-pump at the moment of engine startup and shutdown. Specially, This research was performed how much is the effect of PSD(Pogo Suppression Device) about the pressure oscillation on the inlet of turbo-pump at the moment of engine startup and shutdown. For analysis, propellant tank PSD and Engine are modelled with Flowmaster which is the commercial 1D program. As the analysis results, even though the PSD is installed in the pipeline, the pressure drop or rising at the moment of engine startup and shutdown is same compared to the case without PSD. However, it was confirmed that PSD reduces the pressure oscillation of the high frequency band as the original purpose of PSD.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.838-842
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• 2017

The thruster valve, which is one of the key components applied to the mono-propellant system for the satellite, has a circular plate spring structure. It can be designed as a structure that does not have positional deformation and particles by friction and repetitive motion. In this study, finite element analysis and verification were performed by setting the width of the circular plate spring as a design parameter with the material, thickness and radius of the circular plate spring as fixed variables. The linearity of the spring constant is shown by the graph that is spring force with displacement. It is confirmed that the optimization design of the circular plate spring is possible by the spring force tendency according to the total area of circular plate spring.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.109-116
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• 2012

A vent-relief valve performs as a safety-valve assembly for liquid propellant feeding system of space launch vehicle, which relives pressurant propellant tanks during the filling and the flight. At vent mode, valve is opened and closed by driving pneumatic pressure, and at relief mode, valve is automatically operated to set relief pressure. In this study, we have analyzed a basic layout of vent-relief valve which is designed using foreign LVs(Saturn) to satisfy requirements of Korean Space Launch Vehicle. The simulation model of vent-relief valve is designed by using the AMESim code to verify design parameters and evaluate pneumatic behaviors of valve. In this study, we performed dynamic characteristic simulations on design parameters. And we could predict opening/closing time and pressures, operating performances on design parameters. Using this results, we could suggest detail design and boundary conditions of design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.72-78
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• 2005

We conducted the performance test of micronozzle having nozzle throat diameter of 1.0, 0.5, 0.25 mm in an ambient pressure. We used N2 gas as a cold gas propellant. We varied chamber pressure from 2 to 20 bar and measured the thrust and mass flow rate. Through the test, we concluded that viscous losses were increased with decreasing chamber pressure. We found that micronozzle performance was higher than orifice performance through thrust comparison.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.329-332
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• 2012

The droplet behavior of 83.9 wt.% HAN water solution was investigated experimentally with various ambient temperature and nitrogen environment. At the initial stage of evaporation under thermal decomposition temperature of HAN, gradual decreasing of droplet diameter was observed. After that, the droplet started to expand due to the internal pressure build up by water nucleation inside the droplet. The micro explosion was observed at higher temperature than the decomposition temperature of HAN and the remaining droplet showed similar behavior of single composition droplet. The decreasing rate was augmented as the ambient temperature increasing.

• Journal of Applied Reliability
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• v.5 no.3
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• pp.343-355
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• 2005

As the propellants decompose, they release nitrogen oxides which reduce the shelf life of the propellants by accelerating decomposition rate. The activated carbon fiber was used to extend the shelf life of the propellants that was stockpiled by the military. It is found that the activated carbon fiber adsorbs the nitrogen oxides which were produced by spontaneous reaction of the propellants. As a result, the activated carbon fiber extend the shelf life of the propellants by reducing decomposition rate of the propellants. If 20g of propellant store with 2g of activated carbon fiber, the shelf life of the propellants can be lengthened by 1.4 times.