• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.59-63
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• 2010

Seven different size of orifice were applied in a constant volume combustion chamber for evaluating the effects of torch-ignition on combustion. The initial flame development and flame propagation were analyzed by the mass fraction burn and combustion enhancement rate. The combustion pressures were measured to calculate the mass fraction burn and the combustion enhancement rates. In addition, the flame propagations were visualized by the shadowgraph method for the qualitative comparison. The result showed that the combustion pressure and mass burned fraction were increased when using the torch-ignition device. The combustion enhancement rates of torch-ignition cases were improved in comparison with conventional spark ignition. Finally, the visualization results showed that the torch-ignition induced faster burn than conventional spark ignition due to the earlier transition to turbulent flame and larger flame surface, during the initial stage.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.166-170
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• 2010

Six different size of torch-ignition device were applied in a constant volume combustion chamber for evaluating the effects of torch-ignition on combustion. The torch-ignition device was designed six different volumes and same orifice size. The combustion pressures were measured to calculate the mass burn fraction and combustion enhancement rate. In addition, the flame propagations were visualized by shadowgraph method for the qualitative comparison. The result showed that the combustion pressure and mass burn fraction were increased when using the torch ignition device. And the combustion duration were decreased. The combustion enhancement rates of torch-ignition cases were improved in comparison with conventional spark ignition. Finally, the visualization results showed that the torch-ignition device the torch-ignition induced faster burn than conventional spark ignition due to the earlier transition to turbulent flame and larger flame surface, during the initial stage. And the initial flame propagation was effected torch-ignition volume.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.363-366
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• 2011

Mixing and combustion experiments with a vent slot mixer were performed in Mach 2 supersonic wind tunnel. Helium and hydrogen gases each were used for the mixing and the combustion experiment with a plasma jet (PJ) torch. The vent slot mixer holds plenty of fuel in the downstream mixing region, even though the fuel is transversely injected. In case of the combustion, the injected fuel is ignited by the PJ torch, and then unburned mixture is burned by shock-induced combustion downstream. Thermal choking in the combustor leads to shock trains in the isolator, causing the unstable combustion.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.53-63
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• 2024

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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.125-134
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• 2015

This is the third paper on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine. It is the first in this series to discuss the effects of the torch device on combustion. The results show that an optimum orifice ratio exists regardless of the torch volume, and a few adverse effects on the combustion are observed for an excessively small orifice ratio. In addition, the torch ignition decreases the initial burn duration, and the decrease in the heat transfer caused by this decreased duration contributes to an increase in the peak combustion pressure. Finally, the torch mostly plays a positive role in shortening the main burn duration when the combustion condition is worsened by a lower methane fraction. Yet, the torch decreases the initial burn duration rather than the main burn as the methane fraction increases.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.88-95
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• 2019

The hydrogen torch ignition system has been widely used to ignite a pure aluminum for aluminum powder combustion system because of its simple ignition method. However, the conventional hydrogen torch ignition system has a disadvantage that requires a high-pressure tank to supply hydrogen, which leads to the increase of the weight. In order to solve this problem, a hydrogen ignition system using $NaBH_4$, a solid chemical hydride, was designed in this study. The thermal decomposition of $NaBH_4$ was initiated approximately at $500^{\circ}C$ and hydrogen was generated. The parameters affecting the thermal decomposition characteristics of $NaBH_4$ were analyzed and the aluminum combustion test was carried out using $NaBH_4$-based hydrogen ignition system to study the applicability to a practical aluminum-combustion propulsion system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.135-146
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• 2015

This paper is the fourth on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine and the second dealing with torch ignition. It discusses the combustion characteristics of torch ignition on the basis of the heat release and visualization. The results show that the jet and/or spout from the torch promote combustion by accelerating the flame front in the main combustion chamber. In addition, a hot gas jet exists when the orifice diameter is 4 mm, whereas the flame passes directly through the orifice if the diameter is 6 mm or greater. In addition, the effect of torch ignition differs according to the combination of the methane fraction, torch volume, and orifice size because various combustion processes occur as a result of the interaction of these parameters. Finally, it was found that the most suitable torch should have an orifice diameter of not less than 6 mm and an area ratio of not more than 0.15 to secure a consistent combustion process in a real engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.91-97
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• 2015

After-burner test facility for gas generators of 75 tonf class liquid rocket engines was designed, which was verified by the facility certification test of the Combustion Chamber Test Facility(CCTF). The purpose of the certification test of the after-burner test facility is to verify the combustion stability of gas torches equipped in the gas generator and the after-burner test facility by using methane and oxygen gases. In the case of the autonomous test, the supply system provided steadily methane and oxygen gases to the after-burner system without pressure drop. The combustion pressure of the gas torch approached the design requirement. In the case of the coupled test, the gas generator ignition and the fuel-rich exhaust gas combustion were successfully carried out, leading to the verification of the test facility.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.54-65
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• 2022

We are developing a compact ignition device that can provide a multi-ignition capability for an upper stage methane engine of a two staged small satellite launch vehicle. Firstly, the multi-ignition device is designed and built as an integral part of an additively manufactured mixing head. Secondly, the ignition device requires no separate high-pressure vessels to store ignition propellants as they are branched out from the main feed lines for the mixing head. We performed experiments at various levels, including igniter autonomous tests, thrust chamber ignition and combustion tests on the new compact ignition device which is integrated in the thrust chamber of one-tonf class liquid oxygen/liquid methane engine, and confirmed stable ignition performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.213-216
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• 2009

In order to see the flame behavior in the gas turbine combustor, combustion test was performed by using sector combustor. Ignition test with torch ignition system was carried out at the various combustor inlet velocity and air fuel ratio. Also, flame blow out limit was measured by changing fuel flow rate with fixed air mass flow rate. In the test results, stable ignition is possible at air excess ratio of 6 and this limit is gradually increased with combustor inlet air velocity. The minimum blow out limit is about 4 at 40 m/s of combustor inlet velocity. This blow out limit is also increased up to about 10 with increasing combustor inlet velocity.