A MEMS glass membrane igniter for improved ignition delay and reproducibility

Seo, Daeban,Jeong, Juyoung,Kim, Taekyu,Lee, Jongkwang Elsevier Sequoia 2017 Sensors and actuators. A Physical Vol.258 No.-

<P><B>Abstract</B></P> <P>A MEMS igniter with improved ignition characteristics and reproducibility is described. A glass wafer was selected as the igniter material for high membrane structural stability. To improve the reproducibility of the igniter, the membrane was designed to realize a flat surface and uniform thickness, which are essential factors for reproducibility. A heater is designed at the under surface of the membrane for direct contact with the propellant. It was expected that this would improve ignition delay compared with the previous glass-ceramic membrane igniter. Numerical simulations are performed to predict and compare ignition characteristics. The designed glass membrane igniter is realized as an array-type using a MEMS fabrication process with a glass wafer. Performance evaluation of the fabricated igniter is conducted through a firing test. At the cubesat’s operational voltage of 15V, the measured ignition delay was 17.1ms, which is almost the same as the numerical simulation result. Additionally, this result is 34.45% shorter than the measured ignition delay of the previous glass ceramic membrane igniter. The reproducibility is evaluated by consecutively igniting five igniters at 15V. The calculated average ignition delay and its coefficient of variation are 17.08ms and 12%, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This study describes a MEMS igniter for improved ignition characteristics with high structural stability and a uniform membrane thickness. </LI> <LI> A glass membrane which had a flat surface and uniform thickness was selected as the igniter material for high membrane structural stability. </LI> <LI> Numerical simulations were performed to predict and compare ignition characteristics. </LI> <LI> The designed glass membrane igniter was realized as an array-type using a MEMS fabrication process with a glass wafer. </LI> <LI> The measured average ignition delay and ignition energy were 17.08ms and 25.6mJ, respectively. </LI> </UL> </P>

소형 점화기의 Pyro Shock 감소 방안

양희원,노영희,송기혁,방기복,고영균 한국항공우주학회 2012 한국항공우주학회 학술발표회 논문집 Vol.2012 No.11

소형추진기관에 적용된 소형 점화기에서 pyro shock의 발생을 확인하였으며, 추진기관 안전성 및 성능에 영향을 미치는 pyro shock을 감소시키기 위하여 점화기의 점화제양 및 내부구조물을 변경하였다. 개선된 점화기의 pyro shock 감소 여부를 확인하기 위하여 CBT 성능 시험을 실시하였으며, 점화기의 기밀여부를 확인하기 위하여 습도시험을 실시하였다. 그 결과 점화기의 최대압력 도달시간이 크게 증가함을 확인하였으며, 습도시험 후에도 성능의 변화가 없음을 확인하였다. 시험 결과를 바탕으로 최종 개선 방안을 선택하였으며, 개선된 점화기를 추진기관에 적용하여 pyro shock 발생여부를 확인하였다. 그 결과 개선된 점화기의 pyro shock이 크게 감소함을 확인하였다. In this study, we observed pyro shock generated by a compact igniter used in a small rocket motor, and thus we modified the amount of ignition agent and material of inner part of igniter to reduce the pyro shock which affects the rocket motor safety and performance. CBT performance test was conducted to verify the decrease of pyro shock from the modified igniter, and the humidity storage test was also conducted to confirm the leakage of the igniter. As a result, the achievement time to the maximum pressure of the igniter was decreased, and there was no change of the performance of the igniter after the humidity storage test. With the final modification method chosen, we applied the modified igniter to a rocket motor and observed the decrease that pyro shock of the modified igniter was considerably decreased.

450 N급 메탄-산소 로켓 엔진을 위한 스파크 토치 점화기 개발

박신영(Sinyoung Park),최이담(Edam Choi),한은조(Eunjo Han),김진건(Jin Geon Kim),이다혜(Dahae Lee),이은광(Eunkwang Lee),이민우(Minwoo Lee) 항공우주시스템공학회 2024 항공우주시스템공학회지 Vol.18 No.1

Adopting an engine igniter with high efficiency and ignition performance is essential for reliable operation of liquid rocket engines. In this study, we developed a spark torch igniter for a 450 N-scale methane-oxygen liquid rocket engine by conducting numerical analyses, igniter manufacturing and validation. Specifically, we conducted a parametric study for maximizing the enthalpy at the igniter exit, specifically by adjusting the mass flow rate, nozzle area ratio, fuel-oxidizer mixture ratio, and the igniter length-to-diameter. The heat transferred via the igniter nozzle exit was computed using 3-dimensional numerical simulations. We also manufactured and tested the igniter based on a deduced design to confirm ignition performance of the designed spark torch igniter. The igniter developed through this study could contribute to the development of practical propulsion systems such as upper-stage engines of small launch vehicles.

Numerical analysis of the thermal characteristics of a gas-dynamic ignition system

이재원,임대홍,서성현,강상훈 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5

As a multiple-start ignition method for liquid-fuel rocket engines, the gas-dynamic igniter has many advantages, such as a simple configuration, low weight and high structural strength. However, because of the complexity of the flow of the working fluid, the details of the thermal processes involved are not clearly understood. In this study, the thermal and flow characteristics of a gas-dynamic igniter are investigated through numerical simulations using the software OpenFOAM. The simulation results show that the pressure within the igniter undergoes oscillations. The axial flow velocity decreases across the pressure wave front so that the kinetic energy of the flow is converted to thermal energy. The temperature increase within the oscillation tube of the igniter is strongly correlated with the entry mass flow. Therefore, the tube inlet area should be designed according to the igniter nozzle flow to achieve the best performance from a gasdynamic igniter.

아마추어 소형로켓 점화기 성능 향상을 위한 실험적 연구

심주현(Juhyen Sim),임승빈(Seungvin Lim),박상섭(Sangsub Park),박완주(Wanju Park),이진성(Jinsung Lee),최재원(Jaewon Choi),홍주현(Juhyun Hong),채재우(Jaeou Chae) 한국추진공학회 2008 한국추진공학회 학술대회논문집 Vol.2008 No.5

현재 인하 로케트 연구회에서는 소형 로켓 모터 점화를 위해 흑색화약 및 PVA수지를 혼합하여 점화기를 제작하고 있다. 하지만 제작 과정의 모호함으로 인해 그 성능이 일정하지 않아, 점화기로서 부족한 점으로 지적되고 있다. 따라서 흑색화약 및 PVA수지의 혼합비에 따른 연소 특성을 파악하여 추진제 점화기 요구 조건 충족 조건을 실험적으로 확인하였다. 특히 추진제 점화기의 요구 조건인 추진제 점화 온도 및 안정 연소 압력 조성에 대하여 중점적으로 다루었으며, 산화제와 연소 촉매의 비율에 따른 연소 가스의 온도 및 압력 변화를 통해 그 경향성을 알 수 있었다. Inha Rocket Research Institute has made the igniter that is combination of black powder and PVA polymer for ignition small rocket. But recent igniter is not satisfy because of the performance of igniter is not identified. So, we confirmed requirement of igniter by comparing of ratio of black powder and PVA through experimental method. Especially we studied with ignition temperature for propellant and stable combustion pressure that is requirements of propellant. We can know the tendency of combustion properties by ratio of oxidizer and combustion catalyst through changing of temperature and pressure of exhaust gas of igniter.

킥모터 점화기 개발 및 성능 시험

고현석(Hyeonseok Koh),길경섭(Gyoung-Sub Kil),김병훈(Byung-Hun Kim),조인현(In-Hyun Cho) 한국항공우주연구원 2007 항공우주기술 Vol.6 No.1

파이로젠 형 점화기를 KSLV-I 킥모터 시스템 요구 조건을 만족하도록 설계하였다. 비행모델 제작에 앞서 신뢰성을 확보하기 위해 구조시험, 환경시험, 연소시험을 수행하였다. 점화기 구성품들의 구조적 강도를 확인하기 위해 수압 시험을 수행하였다. 극심한 환경 조건에서 점화기가 정상적으로 작동하는 지를 확인하기 위해 충격 및 진동 시험을 고려하였다. 그리고 초기 조건의 변화에 따른 점화 특성을 이해하기 위해서 연소시험을 수행하였다. 최종적으로 지상 시험을 통해 킥모터 추진제를 점화시키기에 충분한 에너지를 공급할 수 있다는 것을 검증하였다. A pyrogen type igniter was designed to satisfy the requirements of KSLV-I Kick Motor system. To insure the reliability of the igniter before the production of the flight model, we have been performed the structure, environmental, combustion tests. The hydraulic test was carried out to confirm the strength of the components of the igniter. The shock and vibration tests were considered to check whether the igniter operates normally under the severe environmental condition. The combustion tests were also performed to understand the ignition characteristics with the variation of initial condition. Finally, we confirmed that the igniter could provide the acceptable energy to ignite the propellant of kick motor at the ground test.

열전지의 신뢰성에 미치는 파이로테크닉 부품의 특성분석

정해원(Hae-Won Cheong),강승호(Sung-Ho Kang),김기열(Kiyoul Kim),조장현(Jang-Hyeon Cho),류병태(Byungtae Ryu),백승수(Seung-Su Baek) 한국추진공학회 2019 한국추진공학회지 Vol.23 No.1

Thermal batteries are also called molten-salt batteries as the electrolyte is mainly composed of molten salt. The molten-salt electrolyte is a solid that does not conduct electricity at room temperature, but when it is melted by a pyrotechnic heat source, it becomes an excellent ionic conductor. Thermal batteries are a kind of pyrotechnic battery because they operate only when the solid electrolyte is melted by the heat energy provided by pyrotechnic materials. Pyrotechnic components used in a thermal battery include heat sources, fuse strips, and an igniter. The reliability of these pyrotechnic components critically affects the reliability and performance of the battery that must supply electricity stably to guided munitions even under extreme environmental conditions. Different igniter types offer different advantages: notch-type igniters offer improved ignition probability, whereas film-type igniters offer improved safety. The addition of metal oxides to the heat paper could improve the burn rate, and the ignition reliability could be greatly improved by using it with a flame igniter at the same time. Using a two-step reduction process, high-purity Fe particles in coral form can be safely obtained.

성냥과 KNSB의 연쇄적인 연소 반응을 활용한 SRM용 점화기 개발

유은주(Eun-Joo Yoo),김요한(Yo-Han Kim),박성현(Seong-Hyeon Park),서형권(Hyeong-Gwon Seo),손윤재(Yun-Jae Son),이기원(Gi-Won Lee) 한국추진공학회 2022 한국추진공학회 학술대회논문집 Vol.2022 No.5

본 논문에서는 SRM의 연료인 KNSB를 연소시키기 위해, 성냥과 KNSB의 연쇄적인 연소 반응을 활용하여 SRM용 점화기를 개발하였고, 이는 기존 사용하던 점화기에 비해 46%p 가량 높은 성공률을 기록했다. 재료의 물성과 실험을 바탕으로 전력원의 전력에 따른 점화기의 점화 지연 시간을 추산했으며, 가장 효율적인 전력 구간과 그에 따른 최소 지연 시간을 측정했다. 데이터를 근거로 본 점화기의 적정사용전력은 45.4~56.4W로 규정하였다. In this paper, in order to burn KNSB, the fuel of SRM, an igniter for SRM was developed by utilizing a chain combustion reaction of a match and KNSB. The success rate has been increased by approximately 46%p, compared to the existing igniter. Based on properties of ingredients and experiments conducted, ignition delay time according to power of the source was calculated. Also, most efficient power range and minimum ignition delay time under the condition were measured. As a result, proper power for the igniter is defined as 45.4W~56.4W.

A Study on Electronic Ballast for Metal Halide Lamps with Adaptive Ignition

Jo, Gye-Hyun,Song, Myoung-Suk,Park, Chong--Yeun The Korean Institute of Electrical Engineers 2004 KIEE International Transactions on Electrical Mach Vol.b4 No.1

Metal halide lamps have been made suitable for use in outdoor illumination systems over many years. They are also widely used in application and commercial lighting due to their attracting properties such as good quality color, rendering and high efficiency. Over the past few years, a considerable number of studies have been conducted on the electronic ballast with hot restarting and resonance phenomenon. However, very few attempts have been made at the adaptive ignition method according to lamp state. This paper proposes an electronic ballast for metal halide lamps with an igniter for adaptive ignition. The proposed electronic ballast can generate different ignition voltages according to the arc tube state. The experimental results showed that the proposed ballast circuit using adaptive igniter is suitable for 70W HQI lamps.

파이로스타터용 점화기 개발

박호준(Ho Jun Park),홍문근(Moongeun Hong),권미라(Mira kwon),이수용(Soo Yong Lee) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.11

파이로스타터는 일종의 가스발생기로써, 내부에 충전되는 저온 고체 추진제의 연소가스를 통해 시동에 필요한 에너지를 터빈에 공급한다. 파이로스타터의 연소관에 충전된 저온 고체추진제를 연소시키기 위한 초기 에너지를 공급해 주기 위해서는 파이로스타터 및 고체추진제의 특성과 형상에 맞는 점화기 설계가 필요하다. 이에 C.B.T 시험을 수행하여 초기 연소실 내부의 충분한 압력 증가를 확보할 수 있는 점화기의 주요 설계 인자를 결정하였다. 파이로스타터의 연계연소시험을 통해 신뢰성 있는 점화 특성을 확인하였고, 점화장약 충전량에 대한 간단한 해석을 수행하였다. A pyrostarter is a sort of gas generator, which supplies the energy to drive turbines by the combustion gas of a solid propellant charged internally. The igniter of the pyrostarter should guarantee the ignition reliability expecially for the solid propellant with a low fame temperature. For the development of the igniter, several closed bomb testes have been performed to decide several design parameters to get a sufficient chamber pressure build-up for the ignition. Moreover, as a result of the firing testes with pyrostarters, the ignition reliability have been verified and the amount of igniter propellants has been reviewed.