• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.48-55
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• 2014

In present study, design and hot fire tests of the pryostarter are conducted. To prevent the turbopump RPM overshoot, regressive mass flow rate profile is applied. Sudden decrease of the mass flow rate at the end of the propellant burning is realized as well. Firing test results show good agreements with the design requirements. Through the study with ignition substance variations, combustion products and ignition performances are improved.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.1
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• pp.18-27
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• 2003

To perform combined tests with propellant feeding system and engine, which were developed for KSR-III launcher, vertical test stand was organized and a series of hot-fire combustion tests were carried out with engines of several injector faceplate types. In hot-fire tests in vertical installation, combustion instabilities occurred right after ignition with an engine without baffle, and such combustion instabilities did not occur at ignition add during mainstage operation for an engine with STS or composite baffle. 1.regular and temporary pressure pulsations(popping) were detected during steady operation with a baffle engine, however a development to combustion instabilities with resonant mode was highly suppressed by baffle. With a series of tests, it was confirmed that the last developed engine, which has composite baffle, was operated successfully in KSR-III flight propulsion system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.142-143
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• 2011

As mentioned above, various safety measures are considered and discussed as hijacking of Korean vessels by pirates is increasing. Thus, the standard for ship's facilities has been partially revised and setting up an evacuation shelter on all vessels sailing dangerous zone has been reinforced. This research aims to discuss crew Citadel set up that has to sail long haul. In addition, measures against potential gas flow have to be taken due to recent pirate armed and portable rocket attacks. There is also a possibility of fire outbreak within the vessel due to its nature. Thus, this research assesses the relevant number of crew Citadel theoretically. It will also make a model by estimating the relevant number of shelters in the event of fire outbreak and implement simulation using FDS.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.135-141
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• 2005

The procedure of conceptual and detailed design of sub-scale combustor using bipropellant swirl or impinging injector with external or internal mixing for a liquid rocket engine are described in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl or impinging injector and 18 main swirl or impinging injectors.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.59-66
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• 2002

A vertical test stand based on launcher propulsion system was constructed and several tests for the determination of cyclogram were carried out. To make an accurate estimation, static and dynamic pressures were measured and analyzed. Especially, static pressure measurements using fast response sensors without extension tubes were used to determine operation sequence more evidently. The standard operation times of final valves were determined in cold flow tests with an engine head, and fire formation time in combustion chamber was checked in an ignition test with an ignitor only. On the basis of these tests, ignition sequence was established and combustion test cyclogram was finally determined. According to combustion test, test results were well matched with the determined cyclogram within 0.05 sec.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.3
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• pp.350-357
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• 2014

MRDS is a short range missile/rocket defense system which protects a main battle tank(MBT) from threats at a short range. It is composed of 2 radars, 2 infrared trackers(IRT)s, 1 fire control computer(FCC), 2 launchers and countermeasures. In this paper, the radar and the IRT models based on sensing errors, the FCC model based on filtering errors, the launcher model based on driving errors and the countermeasure model based on flying errors are proposed to analyze the defense performance with the approaching RPG-7 and the moving MBT. The simulation results are presented to evaluate and verify the effectiveness of the proposed method.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.5
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• pp.84-91
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• 2010

For the successful development of 75-tonf-class liquid rocket engine, a plenty of tests on each engine component have to be performed and this is equally true for a combustor. However the test facility which is in operation at Korea Aerospace Research Institute lacks its capacity to perform fire tests of a 75 tonf class combustor at its nominal thrust. Since the test facility has to be ready prior to the start of development tests, it is very urgent to establish the test facility. The preliminary design of a test facility for a 75 tonf class combustor which was performed according to such a necessity is described in the paper.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.46-54
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• 2015

Nitrous oxide is known as green and safe propellant, and can be supplied by its own vapor pressure. So, many liquid propulsion research institutes and university laboratories use nitrous oxide as oxidizer of experimental liquid rocket engine. However, the unknown explosions occurred twice during hot fire experiments using subscale ethanol/nitrous oxide thruster. In this paper, we surmised that the explosions were caused by the decomposition of nitrous oxide in the injector body and the recondensation of nitrous oxide. Improvement and the safe handling methods are suggested.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.58-62
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• 2012

In this study, the hybrid rocket was developed that has a thrust of 1000 kgf level. The static fire test was shown that the thrust was 700 kgf level and trajectory was predicted by the maximum altitude of 12.5 km. The L/D ratio of KHyRoc-I has 28, but the KHyRoc-II were designed the small L/D ratio(18.3) using the seamless aluminium tube(Diameter : 250 mm). And KHyRoc-II has a thrust of 900 kgf level, that is designed with internal ballistics and trajectory was predicted by the maximum altitude of 7.4 km.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1995.05a
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• pp.171-175
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• 1995

Semiconductor diode lasers that can generate one watt or more of optical energy for tens of milliseconds (quasi continuous wave) are now readily available. Several researchers have demonstrated that this power level, when properly coupled, can reliably initiate pyrotechnic mixtures. This means that the initiator containing the pyrotechnic can be protected against inadvertent initiation from electromagnetic radiation or electrostatic discharge by a conducting Faraday cage surrounding the explosive. Only a small dielectric window penetrates the housing of the initiator, thereby eliminating the conductors necessitated by a bridgewire electroexplosive device. The diode laser itself, however, functions at a low voltage (typically 3 volts) and hence is susceptible to inadvertent function from power supply short circuits, electrostatic discharge or induced RF energy. The rocket motor arm-fire device de-scribed in this paper uses a diode laser, but protects it from unintentional function with a Radio Frequency Attenuating Coupler (RFAC).The RFAC, invented by ML Aviation, a UK company, transfers power into a Faraday cage via magnetic flux, thereby protecting the diode, its drive circuit and the pyrotechnic from all electromagnetic and electrostatic hazards. The first production application of a diode laser and RFAC device was by the Korean Agency for Defense Development.