• 한국연소학회:학술대회논문집
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• 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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• pp.137-142
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• 2003

In order to investigate the effect of fuel mixing on PAH and soot formation, four species of methane, ethane, propane and propene have been mixed in counterlfow ethylene diffusion flame. Laser-induced incandescene and laser-induced fluorescene techniques were employed to measure soot volume fraction and polycyclic aromatic hydrocarbon (PAH) concentration, respectively. Results showed that the mixing of ethane (or propane) in ethylene diffusion flame produces more PAHs and soot than those of propene, even though the propene diffusion flame produces more PAHs and soot than that of propane and ethane. Considering that propene directly dehydrogenates to propargyl radical, this behavior implied that the enhancement of PAH and soot formation by the fuel mixing of ethylene and ethane (or propane) cannot be explained by propargyl radical directly dehydrogenated from ethane (or propane).

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.112-117
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• 2004

The effects of laser heating on soot formation and oxidation of propylene diffusion flames have been studied experimentally under nearly sooting conditions. The non-sooting flame can be converted to a sooting flame when the laser light heats up a flame at 7 mm height, while a sooting flame can be changed to a non-sooting flame when a flame is heated with laser light at flame height of 13 mm. The selective heating at the soot formation and/or oxidation region determines the sooting behavior of a diffusion flame. The increased soot/flame temperatures are most likely to be responsible for both the decreased and increased soot formation/oxidation.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.139-140
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• 2012

In laminar non-premixed flame situation, the flamelet model is not suitable for simulating slow processor like soot and radiation. Thus in this study, we overcome this limitation by using the transient flamelet model. Also, for soot formation on laminar non-premixed flame, transient flamelet coupled with two-equation soot model has been adopted due to its inherent advantages in terms of accuracy and availability. Based on numerical results, the detailed discussion has been made for the precise structure and soot formation processes in the pressurized methane air flames.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.137-138
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• 2012

The two-equation soot model based on the transient laminar flamelet model is implemented for soot formation of laminar non-premixed $CH_4/Air$ flame with detailed chemical reaction mechanism and complex thermodynamic properties. The soot model represents nucleation, growth and oxidation with gas-phase chemistry. This represented unsteady flamelet soot model has been tested and compared using well verified reference calculation result obtained solving the Full Transport Equations method.

• 대한기계학회논문집B
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• 제20권9호
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• pp.3007-3014
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• 1996

The instantaneous flame temperature and soot formation and oxidation in a D.I. diesel engine are measured using a two-color method. The proposed method based on the continuous spectral radiation from the soot particles in the flame is applicable to industrial diesel engines without major modifications of their main characteristics. Measurements are performed at one location inside the combustion chamber of a D.I. diesel engine. Effects of different engine speeds and loads on flame temperature and KL factor which is an index of soot concentration were examined. Little temperature change were observed with increasing rpm, while increased with loads. The higher the flame temperature is, the lower the KL factor is.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.3-9
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• 2003

By utilizing a semi-empirical soot model, the applicability of the laminar flamelet concept for simulating the formation and oxidation of soot in the laminar diffusion flame has been studied. The source terms for two transport equations of the soot formation and oxidation are calculated in the mixture fraction/scalar dissipation rate space for laminar flamelets and stored in a library. In this study, emphasis is given to the interaction associated with radiation and soot formation. The radiative heat loss is obtained by solving the radiative transfer equation using the unstructured grid finite volume method with the WSGGM. The calculated temperatures and soot volume fractions agree relatively well with the experimental data and the previous numerical results of Kaplan et al. using the detailed chemistry.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.173-182
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• 1997

The instantaneous flame temperature and soot formation and oxidation in a D. I. diesel engine are measured by using a two-color method. The proposed method based on the continuous spectral radiation from the soot particles in flames is applicable to industrial diesel engines without major modifications of their main characteristics. Measurements are performed at one location inside the combustion chamber of a D.I. diesel engine. Effects of different engine speeds and loads on flame temperature and KL factor which is an index of soot concentrations were examined. A little temperature change were observed with increasing engine speed, while increased with loads. The higher the flame temperature is, the lower the KL factor is.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.261-264
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• 2015

Soot particles of diesel and bunker-A with different sulfur contents were generated by pyrolysis with varying conditions of fuel flow rate and residence time in the ceramic tube at $1300^{\circ}C$. TEM and particle size analyzer were used for analysing the primary and the secondary particle size distributions. The results showed that the sulfur content in fuel influences soot inception while the fuel concentration and residence time affects the growth of incepted soot particles.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.257-260
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• 2015

Light extinction characteristics of soot particles in ethylene and propane inverse diffusion flames have been experimentally investigated. The measured data suggested that the refractive index of soot particles varies with light wavelength due to PAH contents existing during the soot growth process. The results showed that the scattering effect is less important as the size of secondary particles rarely affects the optical properties of the soot even when the size is large enough to deviate from Rayleigh assumptions.

• 한국분무공학회지
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• 제15권1호
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• pp.31-37
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• 2010

The aim of this work is to investigate the spray and combustion characteristics of dimethyl-ether (DME) at various injection conditions. The spray characteristics such as spray tip penetration and spray cone angle were experimentally studied from the spray images which obtained from the spray visualization system. Combustion and emissions characteristics were numerically investigated by using KIVA-3V code coupled with Chemkin chemistry solver. From these results, it revealed that DME spray had a shorter spray tip penetration and wider spray cone angle than that of diesel spray due to the low density, low surface tension, and fast evaporation characteristics. At the constant heating value condition, DME fuel showed higher peak combustion pressure and earlier ignition timing, because of high cetane number and superior evaporation characteristics. In addition, the combustion of DME exhausted more $NO_x$ emission and lower HC emission due to the active combustion reaction in the combustion chamber. The result shows that DME had a little soot emission due to its molecular structure characteristics with no direct connection between carbons.