• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.321-327
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• 2010

마이크로 크기의 단일 알루미늄 해석을 위한 간단한 모델을 작성하고, 현상의 주요 파라메터를 도출하는 연구를 수행하였다. 금속 입자의 연소는 점화와 준정상상태의 연소 단계로 구성하였고, 각 단계는 액적 연소의 경우와 유사하게 보존 및 이송 방정식들을 사용하여 모사되었다. 모델은 기존의 실험 데이터와의 엄격한 비교를 통해 신뢰성을 검증하였고, 이 과정에서 현상의 주요 변수를 도출하여 그 영향을 평가하였다. 주요 변수로는 초기 입자크기, 산화 피막 두께, 대류 열전달의 유무, 외기온도, 압력 등이 선정되었고, 간단한 열역학적 모델임에도 불구하고 정량적으로 실험 데이터와 유사하게 각각의 파라메터의 영향을 평가할 수 있음을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.255-263
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• 2006

In order to measure the acoustic amplification factor of an Al/HTPB propellant, T-burner tests using pulsed DB/AB method were conducted. In the experiment, powdered aluminum content was varied to a certain extent. Simultaneous ignition on the internal surface of a propellant was achieved by the use of a fast ignition disk. From the experimental data, the damping factor for a non-zero aluminum content could not be calculated due to the fast attenuation of perturbed pressure. Therefore, the addition of aluminum particle was more than sufficient to stabilize pressure-coupled instability.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.128-130
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• 2017

수중추진을 위한 고체추진제로 알루미늄 분말의 수반응성을 높이기 위하여 $NaBH_4$를 첨가하였다. 알루미늄 분말은 $NaBH_4$의 첨가량에 따라 다른 연소특성을 보였다. $NaBH_4$를 첨가하였을 때 끓는점보다 훨씬 낮은 온도에서도 물과 반응하여 연소되었다. 본 연구에서 $NaBH_4$는 Al 분말과 증기 반응을 촉진시키는 효과적인 첨가제임을 확인하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.241-243
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• 2012

Experiments were conducted to get the design concepts for the continuous aluminum particle feeding system. Two opposed cylinders were used. Aluminum particles in one cylinder were ejected to the air by the supplying gas and the pressure of the other cylinder. It was not possible to eject more aluminum mass flowrate than that of gas if particles were just thrust by the pressure difference between two cylinders. Aluminum particle/air mixture in the flow system was successfully ignited by the electric spark.

• The Korean Journal of Ceramics
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• 제6권3호
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• pp.250-257
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• 2000

The feasibility of synthesizing SiC-AlN solid solution by field-activated combustion synthesis was demonstrated. At lower fields of 8-16.5V/cm, composites of AlN-rich and SiC-rich phases were synthesized, but at fields of 25-30 V/cm, the product was a 2H structure solid solution. Combustion synthesis of the solid solution by nitridation of aluminum with silicon carbide under a nitrogen gas pressure of 4-8 MPa was also investigated. The maximum combustion temperature and wave propagation velocity were found to be influenced by the electric field in the field-activated combustion synthesis, and by the green density and nitrogen pressure in the combustion nitridation. In both cases the formation of solid solutions is complete within seconds, considerably faster than in conventional methods which require hours.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.185-192
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• 1997

The combustion of cellulose insulation treated with Borax, Boric acid and Aluminum Sulfate as combustion retardants is examined by candle type combustion tester. The cellulose fibers in cellulose insulation are classified by diameter as less than 0.2mm, 0.2mm-0.5mm, 0.5mm-2mm and more than 2mm. The burning behavior of cellulose insulation are studied by LOI (Limit Oxygen Index: Beginning point of smoldering), L- point (Lower point of combustion transition from smoldering- flaming to flaming combustion), LOI, L-point and H-point rise with the increasing particle size of cellulose fibers because thermal decomposition rate of cellulose fiber decreases. The phenomena of combustion transition from smoldering to flaming combustion are determined by the generating rate of combustible gas and the formation rate of combustible gas mixture within the zone of cellulose fiber heated.

• 한국추진공학회지
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• 제23권2호
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• pp.78-86
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• 2019

복합 고체추진제에 포함된 금속 연료인 알루미늄은 산화피막에 의해 연소 표면에서 점화, 연소되지 못하고 일부분 녹아 주위 알루미늄 입자들과 응집한다. 추진제 성능 평가 및 설계를 위해 응집된 입자의 크기 및 분포를 예측하기 위해 모델링을 수행하였으며 직접 실험을 통해 응집된 입자의 크기 및 분포를 비교 및 검증하였다. 예측값은 실험과 동일하게 압력에 따라 평균직경이 감소하는 경향을 나타내었으나 압력이 증가할수록 오차가 증가하였다. 응집 입자 분포그래프는 최고점에서의 직경이 일치했지만 체적 분률에서 차이가 나타났다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.5-8
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• 2013

The ignition of aluminum particles under high pressure and temperature conditions is studied. The laser ablation method is used to generate aluminum particles exposed to pressures ranging between 0.35 and 2.2 GPa. A continuous wave $CO_2$ laser is then used to heat surface of the aluminum target until ignition is achieved. We confirm ignition by a spectroscopic analysis of AlO vibronic band of 484 nm wavelength. The radiant temperature is measured with respect to various pressures for tracing of required heating energy for ignition. Then the ignition temperature is deduced from the radiant temperature using the thermal diffusion equation. The established ignition criteria for corresponding temperature and pressure can be used in the modeling of detonation behavior of heavily aluminized high explosives or solid propellants.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.123-132
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• 2002

A numerical study was conducted to investigate the combustion phenomena of normal start and unstart processes based on ISL's RAMAC 30 experiments with different diluent amounts and fill pressures in a ram accelerator. The initial projectile launching speed was 1.8 km/s which corresponded to the superdetonative speed of the stoichiometric $H_2/O_2$ mixture diluted with 5 $CO_2$ or 4 $CO_2$. Experiments with same condition except for projectile surface material demonstrated that ignition was successful with an aluminum projectile, but no combustion was observed in case of a steel projectile. In this study, it was found that neither shock nor viscous heating was sufficient to ignite the mixture at a low speed of 1.8 km/s, as was found in the experiments using a steel projectile. However, we could succeed in igniting the mixtures by imposing a minimal amount of additional heat to the combustor section and simulate the normal start and unstart processes found in the experiments with an aluminum projectile. For the numerical simulation of supersonic combustion, multi-species Navier-Stokes equations coupled with a Baldwin-Lomax turbulence model and detailed chemistry reaction equations of $H_2/O_2/CO_2$ suitable for high-pressure gaseous combustion were considered. The governing equations were discretized by a high order accurate upwind scheme and solved in a fully coupled manner with a fully implicit, time accurate integration method. The numerical results matched almost exactly to the experimental results. As a result, it was found that the normal start and unstart processes depended on the strength of gas mixture, development of shock-induced combustion wave stabilized by the first separation bubble, and its size and location.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.77-80
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• 2013

An analytical study on performance of superdetonative mode ram accelerator was conducted for understanding the S225 experimental result of ISL. It would be noticeable that ISL S225 experimental result could be analytically simulated with the assumptions of inlet shockwave, equilibrium combustion chemistry, temperature dependent specific heat, and C-J oblique detonation in superdetonative operation mode. As result, the S225 experiment could be affected by heat of aluminum. Also, this study showed that the improper assumption, like isentropic assumption on shockwave, or constant specific heat on combustion, might cause misunderstanding about experimental result.