• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.93-96
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• 2009

Advances in high speed flight technologies and engine efficiencies increase heat load on the aircraft. As the temperature of air flow is too high to cool the structure at hypersonic flight speeds, it is necessary to utilize the aircraft fuel as the primary coolant. By undergoing endothermic reaction, such as thermal decomposition or catalytic decomposition, aircraft fuels have heat sink potential. These fuels are called endothermic fuels. The endothermic reaction can be improved by catalysts, but limited by coke deposition. In this study the essential technologies of endothermic fuels are described, and intended to be used for basic research.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.2
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• pp.71-79
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• 2010

As hypersonic flight speeds and engines efficiencies increase, heat loads on an aircraft and it's engine increase. Because the temperature of the air flow is too high to cool the aircraft structure at hypersonic flight speeds, it is essential to use the aircraft fuel as the primary coolant. 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. The endothermic reactions are improved by catalysts which change the extent of reaction and product distribution. At high temperature, liquid hydrocarbons would lead to coke formation that can reduce the effectiveness of heat exchanger and cause rapid degradation of the catalyst, thus endothermic capacity of endothermic fuels is limited to the temperature at which coke doesn't form. In this study, the essential cooling technologies by applying endothermic fuels and the properties of the endothermic fuels are described.

• Journal of Aerospace System Engineering
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• v.13 no.4
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• pp.43-49
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• 2019

In this study, a test equipment which enables to feed endothermic fuel which is heated in the inside and outside environment of a high-speed vehicle and evaluate the heat exchangers' performance was designed and manufactured. For smooth operation of the test equipment, a test procedure that supplied endothermic fuel at high temperatures was established. The catalyst performance test was conducted based on the supply condition of the endothermic fuel and the amount of heat absorbed was analyzed. The validation of the test equipment was proved by comparing the results of catalytic reaction with the previous studies under similar reaction condition. This test equipment can be utilized in the endothermic reaction tests of catalyzed endothermic fuel under various conditions.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.4
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• pp.499-509
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• 1999

This study was carried out to investigate the effects of wearing disposable diaper with the endothermic agent on thermoregulatory response of infant. Five healthy female infants aged about 5 months were taken as a subject of this experiment. Experimental diapers were six kinds of disposable diaper constructed of nonwoven tissue, fluff pulp, super absorbent polymer, back sheet film, leg elastic, and 0g urea(A) 1g urea(B) , 2g urea(C), 3g urea (D), 4g urea(E) 5g, urea(F) respectively. Urea(98% or over purity) was used as an endothermic agent. Experiment was proceeded while infants were sleeping at 27.5$\pm$0.5$^{\circ}C$, 50$\pm$5% R.H, 0.04m/sec. Each disposable diaper's properties was tested. During the experiment rectal temperature skin temperature of 9 areas temperature inside the disposable diapers were measured, the results were as follows : 1) There was not significant difference among the diapers in absorption capacity retention capacity and rewet(p=0.05). The absorption under load was showed to A, B,

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.122-125
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• 1973

A study on the endothermic peak of transformation of the pyrolusite was made by using differential thermal curves for analytical reproducibility, and it was done in quantity on range from 50 mg to 450 mg of pyrolusite species. The separation of ${\alpha}-MnO_2$ peak was impossible due to the overlapping between $\alpha$ and pyrolusite peaks, and the pyrolusite was determined among the species, ${\gamma}-MnO_2$ and ${\delta}-MnO_2$, with an error ranging from $5{\%}$ to $10{\%}$.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.56-61
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• 2021

In this study, Al₂O₃ and H-ZSM-5 were coated on the inner wall of the stainless steel tube for the stable use of liquid hydrocarbon fuel and an endothermic catalyst used as coolant for hypersonic flying vehicles. Coke production is inevitable by the endothermic decomposition reaction of the liquid hydrocarbon fuel, and Fe, Ni metals induce the production of the filamentous coke by using a stainless steel tube reactor as a cooling channel. By coating the stainless steel with H-ZSM-5, Fe and Ni metals are prevented from being directly exposed to the liquid hydrocarbon fuel, and the formation of the filamentous coke is inhibited. In addition, Al₂O₃ is coated between the stainless steel and H-ZSM-5 to enhance adhesion bond strength.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.389-390
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• 2000

최근 지구 온난화의 55% 이상을 차지하고 있는 이산화탄소를 유용한 화합물로 전환하고자 메탄을 환원제로 사용한 이산화탄소 개질반응으로부터 합성가스 생성에 관한 연구가 활발히 진행되고 있다. 메탄의 이산화탄소 개질반응은 수증기 개질반응보다 낮은 합성 가스비의 생성, 온실효과를 유발하는 이산화탄소의 저감, 반응의 높은 흡열도를 이용한 화학에너지 전송 시스템의 응용 면에서 그 의의가 있다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.31-31
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• 1998

위성체의 보조추진시스템은 임구궤도까지의 궤도진입 및 임무궤도상에서의 속도 또는 자세제어에 필요한 임펄스를 제공한다. 단일하이드라진 추력기는 하이드라진(H$_2$H$_4$)과 자발적 촉매(Shell 405)의 발열 및 흡열 열분해 반응에 의해 발생하는 질소($N_2$), 수소(H$_2$), 암모니아(NH$_3$), 혼합가스를 노즐을 통해 방출하므로써 요구되는 impulse를 얻는다. 단일하이드라진 추력기 설계는 주입기, 촉매대, 노즐과 기타 설계 형태에 따른 다지관, 링, 스크린, 지지판 등의 부수적인 부품으로 구성된다. 추력기 제작 과정은 크게 piece-parts 기계가공, HEA(Head End Assembly)와 TCA(Thrust Chamber Assembly)로 구성되고 각 세부공정마다 전수시험 및 검사를 가진다. 연소시험설비는 최소 모사진 공 수준이 고도 100,000 ft(8.4 torr)를 만족시킬 수 있는 진공설비, 시험제어부, 성능변수 측정 및 처리부, 추진제 가압 공급부, 기타 환경 안전 및 부대 설비로 구성된다. 추력기 연소성능시험 절차는 추진제 충전 및 오염 여부 표본 검사, 가압 및 공급 라인 이상여부 확인, 추력기 장착, 추진제 가압 및 공급, 시험장치 보정, 진공 모사 및 연소성능시험, data 처리 등으로 구성된다.

• Polymer(Korea)
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• v.24 no.3
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• pp.306-313
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• 2000

Polycaprolactone (PCL) macromer containing terminal methacrylate group was synthesized by ring-opening polymerization. The number average molecular weight of PCL macromer was 11600 g/mole and polydispersity index was 1.09. The synthesized PCL macromer was copolymerized with styrene by stable free radical polymerization using 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), benzoyl peroxide, and well-defined poly(styrene-g-caprolactone)s were synthesized. The synthesized copolymers was characterized by $^1$H-NMR and gel permeation chromatography equipped with multiangle laser light scattering detector. Thermal properties of graft copolymers were investigated by DSC.

• Clean Technology
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• v.22 no.3
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• pp.190-195
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• 2016

The thermal decomposition of waste energetic materials such as TNT, RDX and composition B in a commercial rotary kiln has previously been carried out. As part of the demilitarization process, the thermal decomposition of homogeneous double base propellant (DB) used in M8 and consisting predominantly of nitrocellulose and nitroglycerine is examined with respect to a number of operating conditions. A single condensed phase reaction with 4 species and 365 gas phase reactions and 59 species are considered. Simulation results show the sensitivity of the thermal decomposition of DB with temperature and velocity. At relatively low velocity with constant inlet hot air temperature, temperature in the rotary kiln was found to be highest, 953 K and 1300 K for cases 3 and 6 respectively. Illustrating that optimum operating temperature can be achieved by controlling the inlet velocity without additional cooling systems.