• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.450-450
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• 2004

• Journal of Energy Engineering
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• v.3 no.1
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• pp.54-61
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• 1994

계단형태의 고온발생장치로서, 고온의 흐름을 형성하고 난류유동이 없이 일정한 혼합기류를 만들 수 있는 2단격막구조 충격파관 장치를 이용하여, 혼합을 동반하지 않는 분무의 착화과정에 관한 실험을 수행하였다. 본 실험에서는 충격파관 속에 하향으로 설치된 초음파 분무기에 의해 자유낙하 상태에 있는 예혼합 분무주를 만들어서 반사충격파에 의해 순간적으로 단열압축시켜서 착화 현상을 관찰하였다. 고온영역과 저온영역에서 얻어진 활성화에너지는 큰 차이가 나며 본 연구에서 얻은 착화지연의 실험결과는 통상의 분무착화 실험인 전기로법, 급속압축기법, 고온기류속에 연료를 분사하는 방법과 다른 현상을 보였다. 그 대표적인 결과에 대한 예로는 착화지연에 대한 압력 의존성과 연료분사율의 영향이 일반적인 분무의 결과에 비해 적게 나타났다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.155-158
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• 2011

유속을 측정하기 위한 다양한 기법들 가운데 양방향 저속 차압 프로브(bi-directional low velocity pressure probe)는 고온의 연소생성물이 존재하는 조건에서 화재유동장의 속도 측정에 가장 적합한 방법으로 인식되어 왔다. 그러나 양방향 유속계의 프로브 상수(probe constant)는 레이놀즈 수와 유동과 프로브의 받음각(attack angle)에 크게 영향을 받게 된다. 본 연구에서는 화재유동장 측정 기법들을 비교 평가하고 양방향 유속계의 받음각에 따른 프로브 상수의 변화를 실험적으로 평가하여 양방향 유속계의 측정 오차를 정량함으로서 화재 유동장 측정의 신뢰성 향상을 위한 기초자료를 제공하고자 한다.

• Journal of Korea Foundry Society
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• v.27 no.6
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• pp.258-262
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• 2007

단섬유강화 고분자 복합재료의 고온압축 프레스 성형 시 유리섬유의 유동을 지배하는 인자인 유리섬유와 모재의 유동성에 관하여 연구하기 위하여 ?h트 스트랜드의 교차각도를 $30^{\circ},\;45^{\circ},\;60^{\circ}$로 배향하여 모재와 적층시킨 다음 열압축프레스를 사용하여 1차로 시트를 제작하고, 이 제작된 시트를 가열로로 가열하여 열압축프레스로 2차 고온압축 프레스 성형한다. 여기서, 압축속도와 압축비를 변화시켰을 때 발생되는 유리섬유의 배향에 관한 실험결과를 고찰한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.19-25
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• 2015

Numerical simulations of the hot gas valve with a pintle have been conducted in order to investigate the effect of numerical methods and computational domains. The grid sensitivity is checked by varying the grid number from 100,000 to 1,700,000. The existence of ambient region doesn't make the significant differences of the flow-field and the temperature distribution. Three turbulence models are adopted to figure out its influence on the thrust and temperature distribution: Spallart-Allmaras, RNG $k-{\varepsilon}$, $k-{\omega}$ SST. The thrusts of the hot gas valve are almost same in all cases of the simulation, however, there are about 5% difference in the temperature distribution. With the ambient region, the difference are observed in the temperature distribution with respect to the number of grids.

• Clean Technology
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• v.20 no.4
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• pp.359-366
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• 2014

Attrition characteristics of PKM1-SU particles, $CO_2$ absorbents for pre-combustion $CO_2$ capture process, and FCC particles, catalytic particles for hydro cracking of crude oil, were investigated at high temperature and high pressure conditions. Particle attrition tests were executed at various kinds of temperature ($0-400^{\circ}C$) and pressure (0-20 bar) conditions in a cylinder type bubbling fluidized bed with 15.1 cm diameter, 120 cm height and 1 mm orifice-sparger tube. Attrited particles before and after tests were analyzed by BET, optical microscopy, and particle size analyzer. Effects of bed material height (solid inventory) and steam injection were also verified by using ASTM D5757-95, conventional attrition test method.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.29-35
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• 2011

The behaviors of combustion-induced internal flows of SRM equipped with fin-slot grain and submerged nozzle are very complex and diverse. Cold air-flow tests for 2D and 3D scale models of SRM have been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tubes also has been visualized through employing various light source and recording directions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.181-185
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• 2010

The behavior of combustion-induced internal flow of SRM equipped with fin-slot grain and submerged nozzle is very complex and diverse. Cold air-flow test for 2D and 3D scale models of SRM has been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tube also has been visualized through employing various light source and recording directions.

• Resources Recycling
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• v.24 no.5
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• pp.3-14
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• 2015

This study investigated that status of domestic and international furnace desulfurization and desulfurization characteristics of limestone for fluidized bed use depending on the technology for CFBC one of the CCPs. Limestone-based desulfurizing agent is one of the superior elements which are optimal at around $850-950^{\circ}C$ on high temperature desulfurization. And effectiveness of desulfurization process can be determined by the desulfurization experiment method such as diffusion reaction of the diaphragm of the absorber surface, the size of the particles, the pores of the quantity, size and structure. And, desulfurization efficiency depending on geological and crystallographic properties and calcination process of limestone needs additional research in the future.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.82-87
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• 2001

The hot deformation behavior of Ti-6Al-2Sn-4Zr-6Mo(Ti6246) alloy was investigated in both the $\alpha$+$\beta$ and $\beta$-phase fields by conducting compression tests over a strain rate range of $10^{-3}s^{-1}$ to $10^0s^{-1}$. The flow stress was increased with increasing strain rate and decreasing test temperature. The flow curves obtained at temperatures below 90$0^{\circ}C$ exhibited a flow softening. However, in the $\beta$-phase field, above 95$0^{\circ}C$, the flow stress increased monotonically with plastic strain approaching steady state values. Constitutive equations for the dependence of flow stress on strain, strain rate, and temperature were developed through the analysis of the flow curves.