• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.196-200
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• 2012

To acquire indigenous development abilities of a future space launcher, bi-propellant liquid rocket engines using environmentally clean propellants such as hydrogen peroxide and methane have been developed by Chungnam national university. The necessary development technologies for the future liquid rocket engines were defined and have been acquired step-by-step in advance by sub-scale liquid rocket engines. Core techniques of design/manufacture/experiments to develop a future prototype liquid rocket engine will be obtained by this study.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.35-44
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• 2011

Mathematical modelling for liquid rocket engine(LRE) main components were conducted to predict the dynamic characteristics when the LRE operates at the transient condition, which include engine start up, shut down, or thrust control. Propellant feeding system is composed of fuel and oxidizer feeding components except for regenerative cooling channel for the fuel circuit. Components modeling of pump, pipe, orifice, control valve, regenerative cooling channel and injector was serially made. Hydraulic tests of scale down component were made in order to validate modelling components. The mathematical models of engine components were integrated into LRE transient simulation program in concomitant with experimental validation.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.63-69
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• 2011

In this study, we developed a dispersion analysis program of the gas-generator cycle liquid propellant rocket engine by expanding the mode analysis software(GEMAT). The performance dispersions of an engine that are arisen from the internal dispersion factors of engine's sub-components were formulated and solved to find the effects of each dispersion factor. We were also able to present the calculation method to find the required pressure margin for the compensation of those dispersion to satisfy the required performances of engine. Using this method, we could propose a novel procedure of compensating during the ground firing test which would induce the performance improvement by lessening the pumps discharge pressures or augmenting the combustion chamber pressure.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.120-126
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• 2005

The method of decreasing the ecological risk for the LRE(Liquid Rocket Engine) test is developed, working on the cryogenic oxidizer and the high-boiling fuel(Kerosene). This Method is based on the study that contains a technical solution method and an accident occurrence range for decreasing of accident probability and damage. This paper contains schematic on the all risk circumstance bring to accident, block-diagram for an accident growth process in case of the propellant leakage, technical solution method and risk reduction evaluation method. It will be used to alternative method for the risk reduction of complex technical systems.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.1
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• pp.68-76
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• 2022

Upper stage of the Korea Space Launch Vehicle-II(KSLV-II) uses a 7-tons class liquid rocket engine and is an open gas generator cycle with a turbopump supply method that uses kerosene/liquid oxygen as the propellant combination. This study first provided a brief overview of the design and development process of the upper stage engine. In addition, it introduced the solutions and results applied to some of the problems that occurred during the development process of the upper stage engine.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1061-1067
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• 2017

Since the 1960s hydrazine is used as a propellant to power rocket, satellites or deep space missions. Due to hydrazine's high toxicity and operating cost, the request for Green Propellant as energetic ionic liquids(HAN, ADN), nitrous oxide blends is growing. Nitrous Oxide Fuel Blend(NOFB) having advantage of a bipropellant performance as well as the advantage of a mono-propellant in respect to the simple propellant tank and feed system. It is worth replacing traditional hydrazine based propellant system if handled and designed properly.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.267-270
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• 2002

Combustion instability, which is one of the most undesirable phenomena in the development of liquid Propellant rocket engine, can cause serious damage to the rocket itself, and must be evaded by all means. Unfortunately, KSR-III rocket went through the combustion instability during engine start at the propulsion test article No.2. To resolve the problem, time sequence has been changed, and the baffle system has been applied. In consequence of the change, stable combustion was achieved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.364.2-364
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• 2002

Thermoacoustic oscillation, which stems from phase correlation between unsteady heat release and acoustic fluctuation, can cause severe vibration and incite the excessive local heat transfer inside the rocket engine. It is very important to understand and prevent this phenomenon in the way of rocket engine development. In this study, the propulsion test facility of KSR-III, which is the first liquid propellant rocket developed by KARI, will be introduced. and the characteristics of thermoacoustic ocillation occurred at the facility will be examined.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.46-52
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• 2002

Characteristics of flow rate control has been studied for a cavitating venturi adopted in a liquid rocket propellant feed system. Both experiment and numerical simulation have been performed to give about 10% discrepancy of mass flow rate for cavitating flow regime. Mass flow rate is confirmed to be saturated for pressure difference higher than $3{\times}10^5$pa when the upstream pressure is fixed to $22.8{\times}10^5$pa and the downstream pressure is varied. The evaporation amount depends substantially to non-condensable gas concentration. However the mass flow rate characteristics is relatively insensitive to the mass fraction of non-condensable gas. So it reduces by only 2% when the non-condensable gas concentration is increased from 1.5PPM to 150PPM. From the previous comparison the expansion of the non-condensable gas and the evaporation of liquid are verified to gave same effect to the pressure recovery pattern.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.89-94
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• 2010

Fuselage propellant feeding system should supply propellants to engine with required flow rate, temperature and pressure. Propellant vibration in engine and feeding line changes feeding characteristics, and frequently inhibits to satisfy the required feeding requirements. Sloshing and POGO vibration are known to be the major vibration phenomena. Concerning sloshing and POGO, vehicle control and structural dynamics aspects are extensively studied, whereas, its effect on propellant feeding performance is not clearly understood. This paper focuses on the deviation of required feeding performance due to propellant vibration. Overall characteristics of propellant vibration and its effect on propellant supply to engine are reviewed and control mechanism for suppressing vibration is introduced.