• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.507-510
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• 2009

The small size of hybrid rocket using PE-$LN_2O$ was designed, constructed and launched for a development basic technology of Hybrid rocket vehicle. The hybrid engine ignition system was designed with valve system using external actuator and confirmed working without any fault. To design fuel grain an internal ballistics design was carried out, and to estimate rockets flight path an external ballistics analysis was carried out. So the rocket was designed and constructed, and the launch test proves that hybrid rocket's design was suitable. The hybrid rocket(weight : 9kg, diameter : 110 mm, height : 1.7 m) was launched successfully. But parachute was deployed on mid-flight and the mission could not finish its purposed flight. Some of problems were found in this activity but next launch vehicle will be improved.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.97-102
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• 2013

A prestudy on expendable turbine engine for high-speed vehicle was conducted. After two possible mission profiles were established to decide the engine requirements, design point analysis was performed with the values of design parameter which were obtained from similar class engines, references, etc. The results showed that specific net thrust and specific fuel consumption with turbine inlet temperature of 3,600 R are 2,599.4 ft/s and 1.483 lb/(lb*h) respectively at the flight condition of sea level, Mach 1.2. It was also found that major design parameters for determining maximum net thrust were turbine inlet temperature for low supersonic and transonic flight speed and compressor exit temperature for high supersonic flight speed from the results of performance analysis on the two possible mission profiles. In addition, simple turbojet engine with an axial compressor, a straight annular combustor, an one stage axial turbine and a fixed throat area converge-diverge exhaust nozzle was proposed as the configuration of simple low cost lightweight turbine engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.5
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• pp.79-91
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• 2008

The present article is intended to introduce the X-51A Scramjet Engine Demonstrator-Wave Rider (SED-WR) program and its core technologies to the korean propulsion community. The X-51A program is lead by the U.S. Air Force Research Laboratory (AFRL) and is sponsored by the U.S. Defense Advanced Research Projects Agency (DARPA). Most of the contents is taken from the paper by Hank et al.[1] with the supplemental materials from additional references. X-51A is a hypersonic experimental vehicle for the flight test of the hydrocarbon fuel-cooled scramjet engine developed by the AFRL HyTech program. The scramjet engine and the hypersonic flight technologies may enter the era of practical use by the completion of the ground tests in 2008 followed by the flight tests scheduled in 2009.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.79-84
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• 2011

This paper presents development activities of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the first rear-drive variant of the GE's T700 engine which is proven for military applications in the world. The main workscope of the development includes a modification from a front-drive engine to a rear-drive one, an performance enhancement of the power turbine and an incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. The first engine run for development and qualification test was successfully completed in 2008. Since the PFRT(Preliminary Flight Rating Test) has been completed, the first flight of the engine installed in the first prototype of KUH has been successfully demonstrated in March, 2010 and the engine installation compatibility tests are being carried out during KUH flight test. The test and evaluation for qualification has been done except for the low cycle fatigue test up to date.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.4
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• pp.74-80
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• 2014

This paper describes the development of the dual-thrust flight motor for enhancing the hit probability of unguided rockets. We designed dual-thrust flight motor by shape modification of the double base propellant with high burning rate, and confirmed the dual-thrust performance by static firing tests. The test results showed the thrust ratio of about 1:7.6 between sustaining phase and boosting phase, and had a quietly normal dual-thrust characteristics. And the results showed that there was not the fire extinction phenomenon of propellant due to the pressure drop.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.70-77
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• 2014

In this paper, the development of unique model of the 2.75 inch rocket propulsion system is described. Recently developed korean 2.75 inch rocket propulsion system shows the improvement of a flame stability resulted from a change in the configuration of propellant grain, and of an incidental ignition protection function using the EMI(electromagnetic interference) filter on ignition system. Moreover it is shown that a directional flight stability is improved by increasing the number of fins and changing the nozzle configuration. Static firing test and thermal shock test were conducted for the validation before flight, and flight test of 210 rounds of rockets was conducted to verify the trajectory uniformity. In addition, intellectual property issues can be overcome with the unique korean 2.75 inch rocket motor as well as the performance improvement.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.62-69
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• 2014

This paper presents a preliminary study of a convergent divergent nozzle in an afterburning turbofan engine of a supersonic aircraft engine. In order to design a convergent divergent nozzle, cycle model of a low bypass afterburning turbofan engine of which thrust class is 29,000 lbf at a sea level static condition is established. The cycle analysis at the design point is conducted by Gasturb 12 software and one dimensional gas properties at a downstream direction of the turbine are obtained. The dimension and configuration of an model turbofan engine are derived from take-off operation with wet reheat condition. The off-design cycle calculation is conducted at the all flight envelope on the maximum flight Mach number of 2.0 and maximum flight altitude of 15,000 m.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.628-635
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• 2010

Properties of bleed air that is air source of ECS(Environmental Control System) can be rapidly changed with airplane engine operating conditions during flight. Therefore, ECS can be operated at a high performance or not during flight. So, high performance ACM has to be developed in order to flight safely. A adaptability of phase changing heat exchanger was esteemed at ACM type ECS in this study. As a result of this study, it is found that ECS outlet temperature can be controlled in a certain range with the phase changing phenomenon.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.506-511
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• 2010

This paper presents development activities of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the first rear-drive variant of the GE's T700 engine which is proven for military applications in the world. The main workscope of the development includes a modification from a front-drive engine to a rear-drive one, an performance enhancement of the power turbine and an incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. The first engine run for development and qualification test was successfully completed in 2008. Since the PFRT(Preliminary Flight Rating Test) has been completed, the first flight of the engine installed in the first prototype of KUH has been successfully demonstrated in March, 2010 and the engine installation compatibility tests are being carried out during KUH flight test. The test and evaluation for qualification of the engine has been done except for the LCF test up to date.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.2
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• pp.71-79
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• 2010

As hypersonic flight speeds and engines efficiencies increase, heat loads on an aircraft and it's engine increase. Because the temperature of the air flow is too high to cool the aircraft structure at hypersonic flight speeds, it is essential to use the aircraft fuel as the primary coolant. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. The endothermic reactions are improved by catalysts which change the extent of reaction and product distribution. At high temperature, liquid hydrocarbons would lead to coke formation that can reduce the effectiveness of heat exchanger and cause rapid degradation of the catalyst, thus endothermic capacity of endothermic fuels is limited to the temperature at which coke doesn't form. In this study, the essential cooling technologies by applying endothermic fuels and the properties of the endothermic fuels are described.