• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제18회 학술발표대회 논문초록집
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• pp.10-13
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• 2002

Pogo is the instability resulting from the interaction between rocket structure and propulsion system of liquid propellant rocket. The coupling of structure and propulsion system can lead to severe problem in rocket. For the analysis of pogo, a time-invariant linearized mathematical model is developed for a selected flight time. Propulsion system is modeled using element representations for each components. The constitutive equation of propulsion system is a homogeneous second-order equation form in the Laplace domain. Rocket structure is modeled using FEM. From the results of modal analysis of structure, the behavior of structure can be represented. System equations for coupling structure and propulsion system are composed of all propulsion system equations and vehicle motion equations reacting on the vehicle by each component of propulsion system. The stability is obtained by the eigen solution of system matrix. The optimization of the design variables such as size, place of accumulator for suppressing pogo instability is carried out. This article of study can be used to determine the degree of stability, and guide the design of pogo suppression system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.384.1-384
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• 2002

Rocket propulsion systems generate very high level noise (acoustic loads), which is due to supersonic jet of rocket propulsion system. In practice, the sound power level of rocket propulsion systems is over 180 ㏈. This high level noise excites rocket structures and payloads, so that it causes the structural failure and electronic malfunctioning of payloads. Prediction method of acoustic loads of rocket enables us to determine the safety of payloads. (omitted)

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.475-478
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• 2005

Ducted 로켓은 가스발생기에서의 1차 불완전 연소반응 및 연소관 내에서의 흡입구로부터 공급되는 공기와의 2차 완전 연소반응을 통해 추력을 발생한다. 로켓의 사정거리는 추진제의 무게, 특히 연료의 무게에 의해 결정되므로 일반적인 고체 추진기관보다 연료효율이 높고 종말속도가 빠르므로 대공, 대함 등의 다양한 추진기관에 적용이 가능할 것으로 기대된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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• pp.207-210
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• 2003

The purpose of this work is to introduce the Remote Control System for KSR-III Liquid Rocket Propulsion System. We developed the high reliable Fire control System that needed for long distance control. We carried out a real time remote control and measuring for KSR-III lust Liquid Propulsion Rocket in Korea using TCP/IP Ethernet network method and Fiber-optic communication method. Also HMI operation program developed guarantee confidential control, monitoring and analysis for Fire control operation.

• 한국추진공학회지
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• 제23권3호
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• pp.112-118
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• 2019

수중운용 체계를 위한 로켓추진기관 개발에 대해 기술하였다. 추력조절이 가능한 LP(Liquid Propellant rocket)형 추진기관 및 HR(Hybrid Rocket)형 추진기관을 선정하여 시스템으로의 적용 가능성을 확인하였다. 축소형 액체로켓연소기 및 이동형 시험대를 개발하여 적용 가능성을 검토하였으며, 수상체계 적용을 위한 추력 1.5톤급 및 추력 1.8톤급 하이브리드 로켓 추진기관을 개발하였다. 시험결과 1.8-톤급 하이브리드 로켓이 수상운용을 위한 추진기관 요구 성능 및 수중 주행 안정성 목표를 성공적으로 달성하였다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.325-327
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• 2004

The longitudinal instability (POGO) of the rocket should not be occurred during the whole flight time for the large class liquid propulsion system to complete a mission successfully. The longitudinal instability is caused by the resonance between the propulsion system and rocket structure in the low frequency range below 50Hz, ordinarily. Analysis on the low frequency dynamic characteristics on the liquid propulsion system with staged combustion cycle engine system was performed as a preliminary study on the longitudinal instability analysis.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.512-521
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• 2017

This paper reports development process of a university-based sounding rocket using simplified hybrid rocket propulsion system for low-altitude flight application. A hybrid propulsion system was tried to be designed with as few components as possible for more economical, simpler and safer propulsion system, which is essential for the small scale sounding rocket operation as a CanSat carrier. Using blow-down feeding system and catalytic ignition as combustion starter, 250 N class hybrid rocket system was composed of three components: a composite tank, valves, and a thruster. With a composite tank filled with both hydrogen peroxide($H_2O_2$) as an oxidizer and nitrogen gas($N_2$) as a pressurant, the feeding pressure was operated in blowdown mode during thruster operation. The $MnO_2/Al_2O_3$ catalyst was fabricated for propellant decomposition, and ground test of propulsion system showed the almost theoretical temperature of decomposed $H_2O_2$ at the catalyst reactor, indicating sufficient catalyst efficiency for propellant decomposition. Auto-ignition of the high density polyethylene(HDPE) fuel grain successfully occurred by the decomposed $H_2O_2$ product without additional installation of any ignition devices. Performance test result was well matched with numerical internal ballistics conducted prior to the experimental propulsion system ground test. A sounding rocket using the developed hybrid rocket was designed, fabricated, flight simulated and launch tested. Six degree-of-freedom trajectory estimation code was developed and the comparison result between expected and experimental trajectory validated the accuracy of the developed trajectory estimation code. The fabricated sounding rocket was successfully launched showing the effectiveness of the simplified hybrid rocket propulsion system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.31-34
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• 2003

가압방식 로켓추진기관시스템의 작동점 변화 추적을 위하여 각 추진제 탱크의 압력, 수위 및 비행 가속도로부터 각 추진제질유량, 연소실압력을 계산할 수 있는 직접상사모델을 만들었다. KSR-III의 비행시험결과 예로 분석하였으며, 이 계산모델을 통하여 가압방식 로켓추진시스템의 작동점 변화의 경향성을 파악할 수 있음을 보였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.853-856
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• 2002

Rocket propulsion systems generate very high-level noise (acoustic loads), which is due to supersonic jet emitted by rocket engine. In practice, the sound power level of rocket propulsion systems is over 180 dB. This high level noise excites rocket structures and payloads, so that it causes the structural failure and electronic malfunction of payloads. Prediction method of acoustic loads of rocket enables us to determine the safety of payloads. A popular prediction method is based on NASA SP-8072. This method was used to predict the acoustic loads of KSR-III rocket. Measurement of acoustic loads by KSR-III propulsion system was performed in the stage qualification test. The predicted results were compared with the measured ones.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.424-427
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• 2008

The longitudinal instability (POGO) of the rocket should not be occurred during the whole flight time for the large class liquid propulsion system to complete a mission successfully. The longitudinal instability is caused by the resonance between the propulsion system and rocket structure in the low frequency range below 50Hz, ordinarily. We can consider various types of propulsion system in the early stage of rocket development. So the longitudinal instability analysis tool is needed for corresponding to each propulsion system. This article deals the generalized method applied to the analysis on the low frequency dynamic characteristics of various types of liquid propulsion system.