• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.5
• /
• pp.90-100
• /
• 2019

Hypergolic thrusters have been extensively researched and applied to spacecraft propulsion based on their simplicity and high reliability of ignition. Research on the impingement characteristics of $N_2O_4$/amine has been profoundly carried out since the 1960s in advanced countries, especially the United States. Recently, enhancements to advanced hypergolic thrusters using MON/MMH have been planned by NASA to improve compactness and high performance. In this work, technical studies were investigated on the mixing of hypergolic propellant and its combustion instabilities such as reactive separation flow and popping.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.545-550
• /
• 2012

High Energy density metal powder has high melting point of oxide film. By this, the ignition source that can make a thermal effect of high-temperature during short time is needed to overcome ignition disturbance mechanism by oxide film. So effective ignition does not occurred with hydrocarbon ignitor, $H_2-O_2$ ignitor, high power laser. But steam plasma can be generate about 5000 K temperature field in short order. Because a steam plasma uses steam as the working gas, it is environmental-friendly and economical. Therefore in this study, we analyze steam plasma temperature field and radical species with optical emission spectroscopy method in order to apply steam plasma ignitor to metal combustion system and cloud particle ignition was identified in visual.

• Journal of the Korean Society of Safety
• /
• v.19 no.4 s.68
• /
• pp.141-149
• /
• 2004

The automobile equipped with a gasoline engine uses the ignition coil, namely, a high voltage generator, to make the mixed fuel ignited and burned in the combustion chamber, which results in the power to drive the engine. The ignition coil functions to convert a low voltage of the primary into a hiか voltage of the secondary by switching method, which will be transmitted to the electrode. Here, if the ignition coil has a defect even a little, it cannot function well. In this study, it was chosen epoxy molding ignition coil in recently and epoxy resin which is insulation material as specimens, and it was measured the characteristics of the partial discharge occurring to the specimens when those were applied to a voltage, and thereby, it was researched and analyzed the distribution of phase angle, amount and count of discharge due to the changing voltage, And as the result is applying to the actual automobile ignition system, it can be expected the enhancement of the performance of the ignition coil and the reliability of the electrical equipment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.252-255
• /
• 2007

Recently military industrial company, utilizing company funded R&D and goverment and industry contracts, has developed ACTS/DACS technology. This technology can be utilized to rapidly steer "smart" bullets, "smart" rounds, tactical missile, cruise missile and kill vehicles for both endo- and exoatmospheric applications. The ACTS/DACS typically consists of a Smart Bus Controller(SCB), a proprietary network firing bus, Smart Pyrotechnic Devices(SPD), rocket motors, and a structure. The SCB communicates with the SPDs over the propretary network firing bus. Each rocket motor contains an SPD which provides rocket motor ignition. Firing energy is stored locally in the SPD so surge currents do not occur in the system as rocket motors are fired. This approach allows multiple, truly simultaneous firings without the need for large, dedicated batteries. Each SPD also functions as a network tranceiver and high reliability fir set all in the space of a single-sided 10 millimeter diameter circuit. The present work develops a new means for igniting explosive materials. The volume of semiconductor bridge (SCB) is over 30 times smaller than a conventional hot wire. We believe that the present work has a potential for development of a new igniter such as smart pyrotechnic device.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.953-961
• /
• 2011

A numerical model of the igniter for the interior ballistics has been developed combining the lumped parameter model with the theoretical equation of the orifice. With the developed model of the igniter, the numerical study on characteristics of the interior ballistics according to the igniter configuration in terms of the igniter length, the side hole diameter, and the distribution of side holes has been conducted. As results of the calculation of the pressure difference between the breech and shot base, the low frequency oscillations have been influenced by the igniter length, while the high frequency oscillations have been affected by the side hole diameter and the distribution of side holes.

• Proceedings of the Korean Society for Cognitive Science Conference
• /
• 2002.05a
• /
• pp.131-136
• /
• 2002

한국어 CVC 음절의 하위 단위는 초성자음과 모음을 포함하는 음절체(body)와 종성자음(coda)으로 이루어져 있고, 영어 음절은 초성(onset)과, 모음과 종성자음을 포함하는 각운(rime)으로 이루어져 있다고 한다. 본 연구에서는 한국인이 영어의 음절을 한국어 음절 정보처리 방법으로 정보처리 하는지를 알아보고자 하였다 실험 조건으로는 음절체 일치 조건(예, 각-감, cap-cat), 각운 일치 조건(예, 남감, pat-cat), 그리고 두 자음 일치 통제조건(예, 김-감, cut-cat)과 무관련 통제 조건(예, ***-감, ***-cat)이 사용되었다. 실험 과제로는 점화 어휘판단 과제(primed lexical decision task)를 수행하였다. 만약 음절체 일치 조건에서의 점화효과가 각운 일치 조건에서의 점화효과보다 크다면 한국인의 음절분절 단위가 음절체-종성(body-coda) 구조일 것으로 예상할 수 있고 각운 조건에서의 점화효과가 더 크다면 그 단위가 초성-각운(onset-rime)구조일 것으로 예상할 수 있다. 실험 결과, 한국어 음절의 경우 각운 일치 조건의 점화 효과가 음절체 일치 조건의 점화 효과보다 크게 나타나 음절체-종성 구조로의 하위 단위 분석을 지지했다. 그러나 영어의 경우에는 각운 일치 조건의 점화 효과가 음절체 일치 조건의 점화 효과보다 크게 나타나 초성-각운 구조로의 분석을 지지하였다. 따라서 한국인이 시각 단어를 재인할 때에는 언어 특정적인 분석을 수행한다는 결과를 얻었다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.17 no.2
• /
• pp.105-113
• /
• 2013

A numerical model of the igniter for the interior ballistics has been developed by combining lumped parameter model with the theoretical equation of orifice. With the developed model of the igniter, the numerical study on characteristics of the interior ballistics has been conducted according to the igniter configuration in terms of igniter length, side hole diameter, and distribution of side holes. As results of the calculation of the pressure difference between the breech and shot base, the low-cycle oscillations have been influenced by the igniter length, while the high-cycle oscillations have been affected by the side hole diameter and the distribution of side holes.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.35.1-35.1
• /
• 2005

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• v.y2005m4
• /
• pp.377-380
• /
• 2005

A study of ignition characteristics of cracked JP-7 fuel with both oxygen and air has been conducted over a wide range of pressures (1-20 atm), temperatures (1200-2000 K), and equivalence ratios (0.5-1.5). Correlations of ignition delay, of the form, $\tau=Aexp(E/RT)[F]^{a}[O_2]^{b}$ are established using the Chemkin-II package and least square analysis. The effect of $C_3$ hydrocarbons in cracked JP-7 fuel is examined by comparing the ignition delays for two different cracked compositions. A comparison for ignition delay is also made with the experimental results obtained by injecting liquid JP-7 fuel in air using a shock tube apparatus.

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