• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.85-90
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• 2018

The objective of this paper is to observe effects of ignition position and time on ignition transition. A gaseous oxygen and liquid kerosene mixture is used as propellant with a shear-coaxial injector. In order to study the ignition delay time and combustion instability intensity, the pressure transducer was used. Sequences, excepting igniter operation time, were fixed to compare the ignition time only. Initial pressure peak and ignition delay time increased as the ignition time was delayed. Additionally, an unstable flame development zone was detected when the igniter was away from the injector.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.19-19
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• 1999

KSR 3단 AKM Motor Case를 개발하기 위해 추진기관 경량화에 가장 유리하고 비강도 및 비강성이 뛰어난 복합재 연소관을 고려하여 직경 300mm급의 축소형 모델을 선행 개발하였다. Netting 이론에 의해 연소관 두께를 결정하고 체적을 최소화 하기 위해 구형으로 연소관 형상을 설계하였다. 연소관을 제작하기 위한 맨드렐은 분리, 조립식으로 설계, 적용하였고 연소관 기밀 유지 및 추진기관 연소시 연소관을 보호하기 위한 삭마성 재료로 EPDM base의 고무 내열재 조성을 개발하였다. 고무 내열재는 맨드렐 위에 적층하고 Vacuum bagging 상태로 Autoclave에서 가황하여 적용하였다. 국내 최초로 Prepreg를 사용하는 Dry process로 고무 내열재가 적층된 맨드렐 위에 Winding하고, Vacuum bagging 상태에서 경화하여 연소관을 제작하였으며, 이 때 사용한 Carbor/Epoxy Perpreg 재료의 기계적 성질 및 열특성 시험을 병행하였다. 제작된 연소관은 수압 시험을 통하여 구조적 안정성을 입증하였고, NDT 검사를 통해 재료간 계면 상태를 분석하였다. 시험이 끝난 연소관은 향후 점화기 개발을 위하여 점화제 종류 및 약량을 변경하여 점화 시험을 수행하여 점화기 개발을 위한 기초 데이터를 확보하였다.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.81-84
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• 2004

다수의 소형 추진모터가 배치된 유도탄의 자세를 제어하기 위해서는 유도탄 비행 중 추진모터를 선택적으로 점화할 수 있는 추력 점화제어기가 필요하다. 점화 제어기가 추진모터 점화를 제어하기 위해서는 수십 채널의 많은 펄스 전류전원이 요구되며, 유도탄 특성상 소형으로 구현되고 고 신뢰성이 보장되어야 한다. 본 논문에서는 다채널 펄스 전류원의 고밀도 소형화 회로를 구현함에 있어 6Sigma 방법을 통하여 신뢰성을 분석하였고, 점화전류 확보를 위하여 필요한 회로경로의 최적화된 설계를 다루었다. 통계적 시뮬레이션을 이용한 설계 최적화는 실험결과를 통하여 그 유효성이 확인되었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.68-74
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• 2006

An experimental study was carried out to investigate the combustion characteristics of the slinger combustor. A combustion test rig was manufactured and installed in KARI combustor test facility. From the ignition test results, we found that there were two major factors influencing the ignition limits; by increasing the rotational speed and the air mass flow rate, a better ignition performance was attained. From the combustion test results, we obtained 99.6% combustion efficiency, 15% pattern factor, and 3% profile factor. The results in this work indicate that the ignition and combustion characteristics of a slinger combustor are markedly different from those of a conventional annular combustor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.85-92
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• 1998

In this paper, we design a sequential system controller, which is capable of processing parallel sequence, on the basis of analysis of control specification described by Petri Net with incidence matrix. The sequential system controller consists of input conditioning unit and petri net control unit which is composed of the token control unit and firing unit. The firing unit determines the firing condition of the transfer signal on the basis of the token status of token control unit. By the proposed scheme, we can easily develop and implement the sequential system controller of automated warehousing system, automated transportation system, elevator system, and so on, as it is possible to modify control specification by changing simply the content of incidence matrix ROM and to expand easily functional capacity as the result of modular design.design.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.750-755
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• 2011

The ignition characteristics of liquid rocket engine thrust chambers which have been developed by domestic technology were analyzed. Analysis results showed that low frequency fluctuation appeared in a partial ignition range according to different temperature profiles and vaporous state in the oxidizer manifold with startup sequences. This low frequency fluctuation wasn't developed as a malfunction factor, but this fluctuation is thought to be taken a continuous concern considering interfaces with engine system and launch vehicle.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.9-14
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• 2007

In this paper, four types of igniters were modeled and their characteristics were researched. And then we analyzed and experimented the effect on the control IC operation in this system. Due to the high ignition voltage, the DC power line on control IC is contaminated with the impulsive noise voltage. So the control IC operation is stopped. Therefore we have found that contamination of DC power noise is reduced by shielding, grounding pattern, and filtering method. We showed that the experimental results are agreed with the theoritical value obtained by the four types of ignitor models.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.397-400
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• 2008

Traditional propellants which have a hypergolic characteristic have a high performance but also have disadvantages of toxicity and complex handling requirement. In order to replace these propellants, one of the alternatives is hydrogen peroxide which generates high temperature oxygen and water vapor after catalytic reaction. In this paper, autoignition characteristics of kerosene by decomposed hydrogen peroxide were investigated to perform fundamental research for designing a thruster using hydrogen peroxide and kerosene propellants. Contraction ratio, whether flame holder exists or not, and feeding pressure of propellants were selected as variables. From the experiments for different mixture ratio, we confirmed the ignition stability is strongly affected by a feeding pressure of propellants.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.15-15
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• 1997

본 연구는 전방점화 방식(the head-end ignition)을 채택하고 있는 composite 고체 추진기관(구룡 1모타)을 이용하여 후방점화 방식(the after-end ignition)에 의한 점화 가능성을 검토하였으며, 점화 방식 차이에 따른 추진기관의 초기 연소거동의 차이점을 고찰하고자 한 실험 연구로서, 후방 점화장치를 설계·제작하여 지상연소시험을 수행하였다. 점화장치는 착화장치(initiation system)와 에너지 방출장치(energy release system), 구조물(Hardware)로 구성되는데, 착화장치는 기존의 K2 squib를 사용하였고, 에너지 방출장치는 FRP튜브에 MTV pellet 점화제를 사용하였으며, 점화기를 후방에 부착시키는 방법으로는 flexible finger 형태의 locking sleeve를 설계하여 노즐목에 고정하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.553-556
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• 2009

In this study, ignition tests of a gas turbine combustor were performed to evaluate an ignition loop at low temperature condition. An experimental setup was constructed to simulate low temperature condition with a heat exchanger using dry ice as a coolant. Various low temperature conditions could be created by controlling the amount of air though the heat exchanger. The results showed that ignition limit decreased with air temperature.