• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.39-43
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• 2005

In this paper, we describe the contents of the achievement of basic experiments for manufacturing and evaluating a micro-rocket using solid propellant, as the device of the micro thrust generator which can be used for attitude control of satellites. We try to analyze performance of the rocket through visualization of the motor jet, and adopt various ignition methods to obtain confidence in ignition problem. For this purpose, we develop and test two different types of thrust measurement system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.381-385
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• 2005

Recently, spacecraft technology trends can be expressed three words, i.e. 'faster, cheaper and smaller'. Among these systems, micro propulsion device is an essential component. Also micro nozzle is the most important part in the micro propulsion device. In case of cold-gas thruster, micro nozzle converts the stored energy in a pressurized gas into kinetic energy through expansion ratio. In this paper we report characteristics of micro nozzle with throat expansion ratio and ratio of specific heats. We measure thrusts using strain gauge based thrust measurement system. We can estimate the micro nozzle performance through experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.45-48
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• 2007

Conventional force sensors such as piezoelectric sensor has limitations for measuring micro/nano-scale thrust. In this study we developed nano-scale measurement system using laser displacement sensor and cantilever. And electrospray microthruster was fabricated by using stainless capillary and extraction electrode, to generate nano-scale thrust. The measurement system can measure the around 90 nN thrust from this thruster. In addition, we designed and fabricated electrospray micro thruster based on PMMA(Polymethyl methacrylate), which has a nozzle protruded from the substrate.

• KIPE Magazine
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• v.14 no.5
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• pp.36-41
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• 2009

전기철도차량에는 대용량 추진제어 컨버터/인버터부터 소용량 스위칭 모드 전원장치에 이르기까지 철도차량의 운행에 필요한 각종 동력 및 전력을 공급하기 위한 여러 가지 형태의 전력변환장치가 사용되고 있다. 그 중 가장 대표적인 전력변환장치가 추진제어인버터와 보조전원장치이다. 전기철도차량의 성능평가는 전력변환장치의 성능평가라 할 수 있을 정도로 많은 비중을 전력변환장치가 차지하고 있다. 한국철도기술연구원은 국토해양부로부터 지정받은 성능시험기관으로서 국내 도시철도 및 철도차량의 성능평가를 수행하고 있다. 성능시험은 차량의 제작공정에 따라 부품시험, 구성품시험, 완성차시험, 예비주행 및 본선시운전의 각 단계별로 실시하고 그 시험기준으로 도시철도차량의 성능시험에관한기준 및 철도차량성능시험 시행지침이 적용된다. 성능시험기준을 근간으로 추진제어인버터와 보조전원장치의 성능시험 대한 시험항목과 시험방법에 대하여 소개한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.77-80
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• 2006

Insensitive Munitions(IM) of solid propulsion system are defined as munitions that fulfil the performance and operational requirements, but will minimize the violence of a reaction when subjected to inadvertant stimuli. It should be clear that the reaction violence of rocket motor subjected to thermal stimuli can be mitigated by reducing confinement prior to propellant reaction. Devices designed to do this by venting the rocket motor case are commonly referred to as mitigation devices. The objective of this paper is to introduce the technical information related to the pyrotechnic mitigation devices for insensitive munition of solid rocket motor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.36-40
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• 2008

Minimization of nozzle induces many flow losses in micro-propulsion system. In this study, we studied about thermal transpiration based new conceptual micro propulsion system to overcome these losses. Thermal transpiration device(Knudsen pump) having no moving parts can self-pump the gaseous propellant by temperature gradient only (cold to hot). We designed, fabricated the knudsen pump and analyzed pressure gradient efficiency of membrane according to Knudsen number under vacuum condition. In this paper, we compared mass flow rate of Knudsen pump by using different membrane type ; Polyimide and Hangi, Korean traditional paper.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.13-13
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• 2000

일반적으로 고체추진 로켓 모타의 개발단계 때 공통적으로 수행되는 주시험(main test)으로는 추력, 압력, 회전률 등의 성능측정을 하기 위한 정적연소시험(static firing test), 내부 정수압(hydrostatic pressure)에 의한 폭발 압력 시험, 연소중이나 연소 후 케이스에 대한 굽힘 강성 시험, 이외에 노화 시험, 환경시험 등이 요구된다. 그러나 신궁과 같은 휴대용 대공 시스템의 추진기관 개발의 경우에는 사수를 보호하기 위해 여러 가지 안전장치들이 설계되고, 이러한 장치들의 성능에 대한 요구 조건들을 확인하기 위한 특수시험(specific test)들이 필요하게 된다. 이러한 특수시험을 위한 각종 시험대들을, 위에서 언급한 주시험을 위해 사용되는 정적시험대(static test bench)들과 구분하기 위해 동적 시험대(DTB : Dynamic Test Bench)라고 한다. 본 연구에서는 신궁 추진기관의 사출모타 점화에서 비행모타 점화에 이르는 일련의 비행절차를 확인하기 위한 동적 시험대 설계 및 제작, 계측장치 구성 및 데이터 획득 방법 등에 관한 내용을 소개하며, 동적 시험대에서 수회에 걸쳐 수행된 동적 시험 결과를 분석/정리하였다.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.4
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• pp.11-18
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• 1998

This study describes sea trial tests for a waterjet propulsion system attached in the hybrid super high speed cargo ship named "Narae". A measuring technique of jet velocity, gross thrust and impeller torque for the waterjet system is explained. From the measured data in sea trial test, performance of the waterjet propulsion system is analyzed and compared with model test results of a similar waterjet system which was carried out in 1996. The erective horse power estimated from sea trial tests shows a good agreement with resistance test results of the model ship. The optimum rising height is estimated as 0.75 m, and the overall efficiency of the waterjet system is predicted as 0.315 at 15 knots. Useful data such as the pump performance, the jet efficiency, the losses of inlet duct and nozzle were obtained. Test results show a similar behavior to the model test results.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.1
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• pp.98-106
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• 2022

To develop reliable dual pulse rocket motor, vacuum ignition performance at high altitude and design stability for rupture pressure of the Pulse Separation Device(PSD) are required. In this study, rupture pressure analysis method for the membrane type PSD of the dual pulse rocket motor was developed. The PSD rupture pressure formulation was derived from strain-pressure relationships. The PSD vacuum rupture test apparatus and the PSD 1 second vacuum ignition test apparatus were developed, which can simulate the high altitude vacuum environment. Rupture pressure of PSD was analyzed by conducting the PSD vacuum rupture test, and design values of PSD were derived. Finally, vacuum ignition performance and rupture pressure of the designed PSD were validated with PSD 1 second vacuum ignition test.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1059-1060
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• 2008

추진장치는 차량의 안전에 큰 영향을 주는 핵심 장치로 철도 선진국들은 이 장치의 크기 및 무게 저감, 스위칭 소음과 노이즈 저감 등에 대한 연구를 활발히 수행하고 있다. 본 논문에서는 한국형 틸팅열차용 주전력변환장치 역행시험결과를 통해 제작된 추진장치의 성능이 양호함을 확인하였다.