• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.17-25
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• 2017

An experimental study was performed for the combustion-field visualization of the burner which burns the liquid hydrocarbon fuel atomized by an ultrasonic oscillator. Configurations of the flame and temperature gradient were caught by both high-speed camera and thermo-graphic camera, and those images were analyzed in detail through a post-processing. In addition, the fuel consumption was measured using the balance during the combustion reaction. As a result, the consumption of atomized fuel increased with the increasing flow-rate of carrier-gas, but any correlation between the air/fuel ratio and carrier-gas flow-rate was not found at the low flow-rate condition. Also, the combustion-field grew and reaction-temperature rose due to the strengthening of combustion reaction with the increasing flow-rate of carrier-gas and power consumption of ultrasonic oscillator.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.3
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• pp.246-251
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• 2017

To fabricate a hydrocarbon polymer electrolyte composite membrane incorporated with Pt nanoparticle, the polymer electrolyte membrane made of a sulfonated-fluorinated hydrophilic-hydrophobic block copolymer (SFBC) and sulfonated poly (ether ether ketone) (SPEEK) blend in the wight ratio of 1 : 1 was synthesized, and a simple drying process was used in order to incorporate Pt nanoparticle into the SFBC/SPEEK film by reducing platinum (II) bis (acetylacetonate), Pt $(acac)_2$. The distribution of the Pt nanoparticles was observed by transmission electron microscopy (TEM), and mechanical and thermal properties were tested by universal testing machine (UTM) and thermogravimetry analyzer (TGA). Cation conductivity, ion exchange capacity (IEC) and I-V characteristics were estimated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.330-333
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• 2008

Present paper introduces the research activities on fuel-air mixing and combustion of supersonic turbulent flows in scramjet combustor carried out in Aerospace Combustion and Propulsion Laboratory of the department of Aerospace Engineering of the Pusan national University. Also, an introduction will be given to the characteristics of the supercritical hydrocarbon fuel combustion in a practical scramjet engine and its numerical modeling approaches.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.47-54
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• 2002

This paper presents the results of an experimental investigation on the combustion of single droplets and 1-D droplet arrays of jet A-1 fuel droplets in atmospheric pressure. Experimental results indicate that burning rate constants$({\kappa}_c)$ of jet A-1 fuel droplets were independent of initial droplet size as $0.915{mm}^2$/sec. It was acquired a general relationship expressing the variation of $d^2$ with time for droplet burning For 1-D droplet arrays $(l/d_o$=1.208{\sim}2.922)$/TEX>, the burning rate constant ${\kappa}_c$ decreased with decreasing droplet spacing $l/d_o$ and, The effect on combustion rate constant ${\kappa}_c$ was stronger to second fuel droplet than third fuel droplet with uniform droplet distance

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.32-39
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• 2018

Supercritical injection behavior of liquid hydrocarbon compounds, which are used as main components of propellant fuel, was analyzed. Decane and Methylcyclohexane (MCH) with different critical points were selected as experimental fluid and Shadowgraphy technique was used. Decane and MCH behave differently in the initial state under the subcritical condition. However, near the critical point, the enthalpy of evaporation became close to 0, so that phase change into supercritical fluid occurred, not vaporization process, and no breakup of both fluids occurred.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.1-9
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• 2011

Researches on hypersonic aircraft technologies have been carried out to increase flight speeds. However, increase in flight speeds causes heat loads that could lead structural change of aircraft's component. Researches on cooling technologies using endothermic fuels are progressing in the USA, France and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical condition of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.279-286
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• 2010

Hypersonic aircraft technologies have been developed with increase in flight speeds. As hypersonic flight speeds increase, heat loads on an aircraft and it's engine increase. Researches on cooling technologies using endothermic fuels are progressing in the USA, France, and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical phase of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.89-92
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• 2006

수소에너지는 화석연료 사용의 증가로 인한 환경오염 및 자원고갈의 문제점을 해결해 줄 수 있는 미래의 청정한 에너지이다. 현재 주 에너지원인 화석연료의 사용에 의하여 배출된 오염물질이 지구온난화와 같은 문제점들을 일으킨다. 이러한 문제점들을 없애줄 수 있는 대안 중 하나가 수소에너지이다. 수소에너지는 자원이 풍부하며 연소시에 오염물질이 배출되지 않는 장점이 있다. 수소에너지는 수소를 연소시켜서 얻는 에너지로써, 수소를 태우면 같은 무게의 가솔린 보다 3배나 많은 에너지를 방출한다. 수소를 생산하는 방법 중 가장 이상적인 방법은 물을 분해하는 방법이다. 그러나 이 방법은 수소를 대량으로 생산하기에는 아직 기술에 대한 확보가 되어있질 않으며, 경제성도 떨어진다는 단점이 있다. 현재 많이 쓰이는 방법 중 탄화수소류의 메탄을 수증기 개질하는 방법이 있다. 메탄 수증기 개질방법은 환경오염물질인 CO나 $CO_2$를 배출한다는 것과 높은 열원이 필요하다 본 연구에서는 C-H결합에너지가 낮아 메탄보다 분해하기 쉬운 부탄의 직접분해로 수소를 생산하고자 한다. 부탄 직접분해는 환경오염물질인 CO나 $CO_2$가 발생되지 않는 장점이 있다. 부탄 분해반응은 $500{\sim}1100^{\circ}C$의 범위에서 이루어 졌으며, 촉매는 탄소계인 카본블랙을 사용하였고, 촉매의 성능을 비교하기 위하여 열분해반응이 동시에 수행되었다.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.1-10
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• 2018

An experimental study was performed for the behavior of the burner flame which results from burning of the liquid hydrocarbon fuel atomized by an ultrasonic transducer. Configurations of the flame and combustion-field were caught by both high-speed camera and thermo-graphic camera, and those images were analyzed in detail through a image post-processing. As a result, the combustion-field grew and reaction-temperature rose due to the strengthening of combustion reaction with the increasing flow-rate of carrier-gas. In addition, a phenomenon of flame flickering was discussed through the comparative analysis of the variational behavior between the visible flame and IR (Infrared) flame-field. Also, the flickering frequency of the flame was confirmed through FFT (Fast Fourier Transform) analysis employing the flame area.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.415-417
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• 2009

A low temperature decal (LTD) transfer method is tried to fabricated hydrocarbon (HC) membrane based MEA. Sandwiched structures of outer ionomer/catalyst/carbon coating/substrate, which had been developed for Nafion membrane, are used for transfer of catalyst to the HC membrane. Performances of the HC MEA before and after 500hr continuous operation are compared and it is found that a severe delamination occurs at the interface between the HC membrane and the catalyst layer, which is the main reason of the low performance and its degradation. The delamination is due probably to the different nature of HC membrane to the Nafion ionomer. A substitutional method, therefore, is suggested to overcome this. In such a way, the outer ionomer process is removed and the low transfer rate of catalyst by skipping the ionomer process is compensated with optimization of other process variables such as transfer time or temperature. The resulting performance is superior to the original LTD method, which can be explained in terms of low resistive components both in ohmic and kinetic.