• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.247-248
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• 2015

Korea rapidly arranged urbanization and overpopulation with high growth of economy and all kinds of decrepit facilities are scattered all over the downtown. If there is a strong wind in fire, fire is rapidly increased by various fire spread factors. And Korea cannot build prediction model of urban fire combustion phenomena because there is no studies that physically explains the suitable flame phenomena for its real state. In this study, for development of Korean Urban fire Simulation on Attenuation of Radiant Heat Flux from Water Screen.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 춘계 학술대회논문집
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• pp.35-40
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• 2002

The dynamic behaviors of the single vortex in a reacting and non-reacting methane-air jet flow were investigated numerically. The numerical method was based on a predictor-corrector for low Mach number flow A two-step global reaction mechanism was adopted as a combustion model. After fuel and air were developed entirely in computational domain, the single vortex was generated by an axisymmetric jet that was impulsed to emit a cold fuel. Through comparisons of single vortex in reacting and non-reacting jet flow, it was found that global dynamic behaviors and the mechanisms leading to the formation, transport processes of vortex ring were influenced significantly by heat release from reaction. In addition, the interaction between a single vortex and flame bulge generated by buoyance effect in a reacting jet flow was found.

• 대한기계학회논문집B
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• 제31권2호
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• pp.109-115
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• 2007

Airframe-integrated Scramjet engines of NASA Langley type consist of a compressor, a combustion chamber and a nozzle. When some disturbances occur in one module of the engine, its influences are propagated to other modules. In this study, it is investigated numerically how shock waves were caused by thermal choking in one module propagate upstream and how they influence adjacent modules. The calculations are carried out in 2-dimensional supersonic viscous flow model using explicit TVD scheme in generalized coordinates. The adverse pressure gradient caused by heat addition brings about separation of the wall boundary layers and formation of the oblique shock wave that proceed to upstream. This moving shock wave formed one module blocks the flow coming into the adjacent modules, which makes the modules unstarted.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3125-3130
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• 2008

Coal is one of the most abundant and cheapest energy sources in the earth, but its typical combustion product, $CO_2$, is related with serious recent environmental issues such as global warming. The Integrated Coal Gasification Combined Cycle (IGCC) with $CO_2$ sequestration is one of the most promising options to produce electricity using a relatively cheap fuel (coal) with minimum impact on environment. In IGCC power generation systems, some chemical reactions are required to gasify coal to produce syngases such as $H_2$ and CO, which would be burnt in the combustor to produce heat for power generation, with a penalty of additional energy consumption. In this paper, several chemical reactions for the gasification of coal are considered and their characteristics are investigated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2856-2861
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• 2008

A catalytic burner has been developed to utilize thermal energy from the fossil fuel without nitrogen oxides (NOx) emission. The burner is shaped into a mat to maximize the heating surface. Premixed combustion has been developed to be used in a closed chamber, such as a radiation type industrial dryer. The burner yields the thermal energy in the form of thermal radiation in the infrared regime, which is proved to be effective to dry organic substances for low moisture condition. Thermal efficiency including the sensible heat is better correlated to the moisture compared to the dry rate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2922-2927
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• 2008

The test of engine performance using the engine dynamometer needs technical researchers and facilities. A variety of CAE analysis programs and DoE(Design of Experiments) are used to analyze data efficiently instead of tests. The study got data from simulations of WAVE that used to model the SI engine to identify performance of engine. DoE makes it possible to know effectiveness of factors for power, BSFC, volume efficiency and find optimum condition in each factor through minimizing number of experiments. CA50 has effect on power and BSFC as volume efficiency is related with cylinder liner temperature and heat coefficients. The final result in DoE could be identified of consistency above 98% after substituting the data to WAVE.

• 설비공학논문집
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• 제7권4호
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• pp.600-610
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• 1995

When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1998년도 제10회 학술강연회논문집
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• pp.29-29
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• 1998

고체 추진제 연소불안정에 관한 해석은 준-정상 1차원 해석인 QSHOD(Quasi-Steady Homogcneous One-Dimension)에 의하여 단순화된 지배방정식을 이용하여 응축영역을 해석하는 것이 일반적이다. 이때 외부교란에 대한 기체영역과 표면반응 영역의 응답은 화학반응이 발생하지 않는 고체영역의 응답에 비하여 매우 빠르므로 준-정상적인 거동을 한다. 본 연구에서는 복사열전달에 의한 열속(heat flux)이 고체 추진제의 표면에 존재하며 이 중의 일부가 고체영역에서 흡수될 때 표면에서의 선형교란을 고려한 ZN(Zeldovich-Novozhilov) 방법을 이용하여 연소불안정 현상을 이론적으로 해석하여 연소불안정 현상을 설명할 수 있는 연소 응답함수를 구하였다. 본 연구에서 얻어진 응답함수를 해석함으로써, Zebrowski등$^{(5)}$ 에 의하여 얻어진 복사열 교란에 대한 응답함수가 과소 평가된 응답특성을 나타내고 있음을 알았다. 또한 응답함수의 고유불안정성을 판별하는 민감계수 r과 k의 영역의 해석으로부터 SOn등$^{(6)}$ 에 의하여 밝혀진 안정 경계선의 안정한 영역보다 본 연구에서 구한 안정 경계영역이 줄어드는 경향을 보여주고 있다. 이것은 (6)에서 과소 평가된 복사열전달의 영향을 수정한 결과 때문이다.

• 대한기계학회논문집
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• 제12권6호
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• pp.1438-1449
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• 1988

본 연구에서는 입자유동을 연속유체(continuous fluid)라 간주하는 2유체모델 을 적용하였고(Fig.2 참조), 실제 유동으로 2상난류제트유동, 관유동에 개발된 모델을 적용하여 모델의 타당성을 검토하였다.

• 한국세라믹학회지
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• 제37권8호
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• pp.768-773
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• 2000

Alnite clinker, which is based on CaO-SiO2-CaCl2 system, was synthesized by recycling Cl-containing waste, and its hydraulic properties were onvestigated. Alinite coinkers with two different chemical compositions were burned for 10∼30 minutes in the range of temperature, 1350∼1450$^{\circ}C$. The microstructures of those clinkers were characterized by powder X-ray diiffracuion analysis, optical microscope, and scanning electronic microscope and heat of hydration of alinite cements which was measured in order to investigate hydraulic properties. X-ray analysis shwoed that f-CaO in both clinkers with different compositions significantly was decreased with transforming C2S(belite) to C3S(alite). From the results of microscopy and scanning electron microscopy(SEM), crystal of synthesized alite(C3S) was larger and better crystallinity than that of ordinary portland cement.