• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.399-404
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• 2010

Test results including the variation of propellant-inlet pressure, pulsed thrust, and environment vacuum with the accompanying thermal responses are presented for the pulse-mode operation of a set of monopropellant hydrazine thrusters producing $0.95lb_f$ of nominal steady-state thrust at an inlet pressure of 350 psia. The test data are reduced into the impulse bit, specific impulse, and force centroid that are the factors typically characterizing pulse-mode performance of small rocket engines. With a scrutiny to the performance parameters, their comparison to the reference criteria of 1 lbf standard monopropellant rocket engine are successfully made.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.409-411
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• 2017

미사일 추력기 체계에 적용되는 하이드라진[$N_2H_4$]추진제는 MSDS-OHS 유해성 분류상 급성독성 물질로서 사용이 제한되고 있는 바, 다양한 대체물질이 개발 중이다. 최근 해외에서 안전성과 취급이 우수한 질산 히드록실암모늄[$NH_3OHNO_3$]과 암모늄 디나이트라마이드[$NH_4N(NO_2)_2$] 기반 단일계 액상추진제가 개발중이며, 이 물질들을 이용한 추력기 시스템 적용 시험이 진행되고 있다. 그러나 저온에서의 연로물질 산성화 반응으로 인한 디나이트라마이드[$N(NO_2)_2{^-}$] 물질의 분해는 나이트레이트[$NO_3{^-}$] 이온 생성을 촉진시키며, 부수적으로 발생하는 침전물은 촉매 및 노즐의 막힘 현상을 유발하므로 추력기 성능의 저해요인으로 작용한다. 그러므로 저온분해 방지를 위한 첨가제 조성 개발 및 열분해 특성 연구가 최근의 관심사이다. 본 연구는 합성/정제/추출한 암모늄 디나이트라마이드 산화제를 주요 조성물로 적용하였으며, 염기성 안정화제를 질량비율 4~5% 첨가하여 산성화 반응을 억제시킨 단일계 액상추진제(KMP) 형태로 제조하였다. 합성한 추진제는 시차주사열량계(DSC)를 이용하여 분해온도를 측정하여 열안정성을 평가해보았다.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.1
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• pp.19-26
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• 2009

The response characteristics of $H_2O_2$ monopropellant thrusters at a pulse mode were presented in this paper. A catalyst bed was fixed to $MnO_2$/$Al_2O_3$ to investigate the thruster design effect to response time. Three different thrusters (50 N class) having different injectors, ullage volumes, catalyst grain sizes, and reactor volumes were prepared to investigate the response characteristics. As a result, the ignition delay, pressure rising and tail-off time of case 2-2 thruster with 16-20 mesh catalyst size were 14, 108, 94 ms respectively, which were comparable to requirement of response time at commercial hydrazine thrusters.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.185-189
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• 2007

A hydrogen peroxide monopropellant thruster has been developed to research performance characteristics of silver catalyst bed. The experiment data and evaluation result from the fire tests with five catalyst beds are presented A scheme of catalyst arrangement is presented for high concentrated hydrogen peroxide.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.1-2
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• 1997

인공위성용 추력기는 위성의 자세제어 및 궤도조정용 소형 액체추진기관으로서 개발기술은 인공위성 그 자체는 물론 위성 발사체와 유도 미사일의 추진기관에 이르기까지 다양하게 확장 적용할 수 있는 핵심 기반기술이다. 때문에 선진국으로부터의 기술 이전을 기대하기 힘든 품목으로, 자체 개발을 통해 위성이나 유도무기에 장착 운용시험을 하기에도 막대한 비용 때문에 회피되고 있는 실정이다. (주)한화는 정부에서 국책과제로 추진하고 있는 KOMPSAT 위성 개발사업에 참여하여 소형 액체 추진기관인 단일 추진제 추력기의 개발을 추진하였다 1994년 11월 사업착수 이래 미국 TRW사로부터 추력기 설계, 해석 및 제작 기술을 이전 받았으며, 추력기 제작/시험 시설을 완공하여 TRW사의 제품 품질 요구조건(product assurance requirements)에 의거 제작에 착수하였다. 현재 총 8세트의 이중 추력기 모듈(dual thruster module)을 제작 납품하였으며 또한 추력기 자체의 핵심 부품을 원부자재 가공으로부터 제작하고 이의 인증 시험을 성공적으로 완료하였다. 현재 국산화 추력기를 KOMPSAT 위성에 장착하기 위한 이중 추력기 모듈 제작이 진행 중에 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.1-10
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• 2010

Design and performance evaluation of $H_2O_2$ monopropellant thrusters to be used at reaction control of space launch vehicles were presented in this paper. Design thrust level was determined as 100, 250 Newton which is nominal thrust level for commercial space launch vehicles. Qualification thruster models including solenoid valves were developed after the reactor design were evaluated at engineering thruster models. Each thruster was evaluated by measurement of characteristic velocity, thrust, specific impulse, and pulse response times at sea level test condition.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.97-97
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• 2004

현재 KSLV-I에서 탑재부의 Pitch, Yaw, Roll의 3축 제어 및 2단부의 Roll 제어를 위해 사용되는 보조 추진 시스템은 구성이 단순하며, 신뢰성이 높은 것으로 알려져 있는 단일 추진제인 하이드라진을 이용하는 추진 시스템을 고려하고 있다. 이러한 하이드라진 추진 시스템은 추력실 전방에 설치되어 있는 추력기 밸브의 ON/OFF를 이용하여 추력을 조절하게 되는데, 이 때 추력기 밸브의 빠른 작동으로 인해 수격현상에 의한 급격한 압력 상승이 발생하게 되어 구조물의 손상을 발생하게 된다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.757-763
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• 2017

The combustion test of LMP-103S, a propellant based on ADN(Ammonium Dinitramide), was performed with a 50 mN scale micro-thruster. The micro-thruster was made with photosensitive glass using MEMS manufacturing process. $Pt/{\gamma}-Al_2O_3$ was used as a catalyst to decompose LMP-103S. After injecting 90 wt.% hydrogen peroxide into combustion chamber to preheat the catalyst, LMP-103S was injected for the combustion test. As a result, the ignition and combustion of LMP-103S was confirmed in platinum catalyst environment with the combustion chamber temperature going up to $650^{\circ}C$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.269-272
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• 2009

Catalytic decomposition of nitrous oxide was investigated experimentally. Two noble metal catalyst (Pt, Ir) were chosen to decompose nitrous oxide. Each catalyst was tested with different chamber pressure and preheating temperature. Ir decomposed $N_2O$ at lower temperature ($230^{\circ}C$) and suitable for $N_2O$ decomposition. In addition, the minimum required preheating temperature decreased as the chamber pressure increased. However, deactivation of Ir catalyst was observed during the experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.49-52
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• 2009

The response times of monopropellant thrusters at a pulse mode were investigated experimentally as design parameters and feed pressure conditions. Five different model thrusters as injection direction/uniformity, aspect ratio of reactor, volumes of manifold and chamber were designed. As a results, two parameters, aspect ratio and manifold volume, were directly related to response characteristics. Additionally, chugging instability at reaction chamber was observed when pressure drop across the catalyst bed was increased due to high aspect ratio or when low pressure was built at reaction chamber.