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

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

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회B
• /
• pp.3073-3078
• /
• 2008

In this study to find out the amount of soot, LII method, which utilizes a laser, was used in laminar diffusion flame and based upon the temperature and soot measured from the turbulent Diesel diffusion flame in the constant-volume chamber using the two-color method. Through these experiments, we could know that the LII signal is generally proportional to the soot amount in a laminar diffusion flame. And we could acquire the temperature and soot using the two-color method in a turbulent Diesel diffusion flame effectively. In addition to, this experiment revealed that the KL factor was high on parts of the chamber where the temperature dropped. On the other hand, the KL factor was low where the temperature increased rapidly. Also, it was possible to measure the highest temperature of a turbulent Diesel diffusion flame is approximately 2300K.

• 한국자동차공학회논문집
• /
• 제2권2호
• /
• pp.12-23
• /
• 1994

In order to investigate the effect of turbulent intensity on combustion characteristics, new flame factor model was developed. The principal study is the evaluation of interaction of swirl, tumble and unstrutural component of flow characteristics and correlation between turbulent intensity and flame factor. Computational and experimental study has been, performed such as quasi-dimensional cycle simulation, three dimensional flow analysis, engine performance test and diagnostic simulation. From these studies, it was found that flame factor was a function of engine speed and turbulent intensity.

• 한국자동차공학회논문집
• /
• 제7권7호
• /
• pp.42-53
• /
• 1999

Two dimensional flame temperature and KL value distribution from the luminous flame containing soot in a DI diesel engine were measured by the tow-color method using tow different wavelengths of the flame image. The combustion chamber of a DI diesel engine was visualized by elongating the piston and cylinder and the flame in the combustion chamber was photographed on a nega-color film using a high speed camera. In this study, color CCD camera was used to digitize the three color density of the film exposed to the flame and standard lamp . The accuracy of the measuring method depends on the calibration line of film made from a high temperature standard tungsten lamp. The formation and oxidization of soot in the diesel engine were studied by observing measured time history of KL factor and flame temperature . Also , effects of various shapes of combustion chamber and fuel injection on flame temperature. Also, effects of various shapes of combustion chamber and fuel injection on flame temperature and KL value distribution were examined.

• 한국연소학회지
• /
• 제3권1호
• /
• pp.31-39
• /
• 1998

The local instantaneous flame temperature and soot concentration in a D. I. diesel engine were measured using a two-color method. The proposed method based on the continuous spectra! radiation from the soot particles in the flame is applicable to industrial Diesel engines without major modifications of their main characteristics because of simplicity and relative ease of application. Measurements were performed at two locations inside the combustion chamber of a D. I. diesel engine. Effects of different engine speeds and loads, fuel injection timings, combustion chamber shapes on flame temperature and KL factor, which is qualitatively proportional to soot concentrations, were examined. Flame temperature change were observed with increasing engine speed and load. The higher the flame temperature is, the lower the KL factor is.

• 방사성폐기물학회지
• /
• 제18권3호
• /
• pp.395-405
• /
• 2020

Compartment fire tests were performed using kerosene and Jet A-1 as fire sources to evaluate the relationship between flame temperature and opening size. The tests were performed for a fire caused by the release of kerosene owing to vehicle impact, and for a fire caused by the release of Jet-A-1 owing to airplane collision. The compartment fire tests were performed using a 1/3-scale model of a metal storage cask when the flame temperature was deemed to be the highest. We found the combustion time of Jet-A-1 to be shorter than that of kerosene, and consequently, the flame temperature of Jet-A-1 was measured to be higher than that of kerosene. When the opening was installed on the compartment roof, even though the area of the opening was small, the ventilation factor was large, resulting in a high flame temperature and long combustion. Therefore, the position of the opening is a crucial factor that affects the flame temperature. When the metal storage cask was stored in the compartment, the flame temperature decreased proportionally with the energy that the metal storage cask received from the flame.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2001년도 제23회 KOSCO SYMPOSIUM 논문집
• /
• pp.97-103
• /
• 2001

The characteristics of flame stability have been studied experimentally using a slot burner. The blowout conditions of a fuel-lean premixed laminar flame, which is located in the middle of fuel-rich premixed laminar flames, are identified for propane, ethylene, and methane flames. The fuel-rich flames could stabilize the fuel-lean flame for the equivalence ratio as low as 0.2. The laminar flame speed along with the heat release rate is likely to be the important factor in stabilizing a fuel-lean flame. The increase of heat release rate on a fuel-rich flame lowers the equivalence ratio limit for the stable fuel-lean flames. The stability of fuel-lean flames, however, was not sensitive to the equivalence ratio of a fuel-rich flame.

• 한국가시화정보학회:학술대회논문집
• /
• 한국가시화정보학회 2007년도 추계학술대회
• /
• pp.149-154
• /
• 2007

This study examines the effect of acoustic excitation using forced coaxial air on the flame characteristics of turbulent hydrogen nonpremixed flames. A resonance frequency was selected to acoustically excite the coaxial air jet due to its ability to effectively amplify the acoustic amplitude and reduce flame length and NOx emissions. Acoustic excitation causes the flame length to decrease by 15 % and consequently, a 25 % reduction in EINOx is achieved, compared to a flame without acoustic excitation. Moreover, acoustic excitation induces periodical fluctuation of the coaxial air velocity, thus resulting in slight fluctuation of the fuel velocity. From phase-lock PIV and OH PLIF measurement, the local flow properties at the flame surface were investigated under acoustic forcing. During flame-vortex interaction in the near field region, the entrainment velocity and the flame surface area increased locally near the vortex. This increase in flame surface area and entrainment velocity is believed to be a crucial factor in reducing flame length and NOx emission in coaxial jet flames with acoustic excitation. Local flame extinction occurred frequently when subjected to an excessive strain rate, indicating that intense mass transfer of fuel and air occurs radially inward at the flame surface.

• Journal of Mechanical Science and Technology
• /
• 제16권4호
• /
• pp.564-571
• /
• 2002

Three-dimensional numerical analysis of the turbulent premixed flame propagation in a constant volume combustion chamber is performed using the KIVA-3V code (Amsden et. al. 1997) by the flame surface density (FSD) model. A simple near-wall boundary condition is eaployed to describe the interaction between turbulent premixed flame and the wall. A mean stretch factor is introduced to include the stretch and curvature effects of turbulence. The results from the FSD model are compared with the experimental results of schlieren photos and pressure measurements. It is found that the burned mass rate and flame propagation by the FSD model are in reasonable agreement with the experimental results. The FSD combustion model proved to be effective for description of turbulent premixed flames.