http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
바이오디젤 및 디젤 연료에 대한 반응 메커니즘과 분무 특성 비교 연구
이영재(Young J. Lee),허강열(Kang Y. Huh) 한국연소학회 2011 KOSCOSYMPOSIUM논문집 Vol.- No.43
This paper describes study on the effects of diesel and biodiesel fuels on spray, combustion and emission characteristics. A combined mechanism of methyl butanoate and n-heptane is employed to model ignition and combustion processes. One mole of soybean oil is composed of one mole of methyl butanoate and two moles of n-heptane as a simplification. The fuel property library in KIVA is expanded to include the thermophysical properties of biodiesel. Spray simulations are performed without combustion to validate the biodiesel properties. Engine simulation is performed in terms of the biodiesel surrogate for practical combustion application.
HCCI 연소 모사를 위한 n-heptane 상세 및 축소 반응 메커니즘 비교/검증에 대한 연구
이영재(Young J. Lee),허강열(Kang Y. Huh) 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-
In this paper detailed and reduced chemical kinetic reaction mechanisms of n-heptane are investigated to understand the complexities of HCCI combustion. The detailed, skeletal and reduced n-heptane kinetic mechanisms are tested for comparison of ignition delays, PSR solution and mole fraction profiles of some radicals. The locally deterministic approach is employed to consider spatial inhomogeneities in an HCCI engine by the KIVA A and CHEMKIN package. Results show some discrepancy between measured and calculated pressures with estimated residual fractions.
디젤 엔진 운전 조건에서 분무 연소 과정과 난류 화염 구조 특성에 대한 해석
이영재(Young J. Lee),허강열(Kang Y. Huh) 한국연소학회 2009 한국연소학회지 Vol.14 No.3
Simulation is performed to analyze the characteristics of turbulent spray combustion in a diesel engine condition. An extended Conditional Moment Closure (CMC) model is employed to resolve coupling between chemistry and turbulence. Relevant time and length scales and dimensionless numbers are estimated at the tip and the mid spray region during spray development and combustion. The liquid volume fractions are small enough to support validity of droplets assumed as point sources in two-phase flow. The mean scalar dissipation rates (SDR) are lower than the extinction limit to show flame stability throughout the combustion period. The Kolmogorov scales remain relatively constant, while the integral scales increase with decay of turbulence. The chemical time scale decreases abruptly to a small value as ignition occurs with subsequent heat release. The Da and Ka show opposite trends due to variation in the chemical time scale. More work is in progress to identify the spray combustion regimes.
직접 관계 그래프(DRG)를 이용한 디젤 연료의 상세 화학 반응 기구 축소화
이영재(Young J. Lee),허강열(Kang Y. Huh) 한국연소학회 2011 한국연소학회지 Vol.16 No.2
It is a challenging task to apply large detailed chemical mechanisms of fuel oxidation in simulation of complex combustion phenomena. There exist a few systematic methodologies to reduce detailed chemical mechanisms to smaller sizes involving less computational load. This research work concerns generation of a skeletal chemical mechanism by a directed relation graph with specified accuracy requirement. Two sequential stages for mechanism reduction are followed in a perfectly stirred reactor(PSR) for high temperature chemistry and to consider the autoignition delay time for low and high temperature chemistry. Reduction was performed for the detailed chemical mechanism of n-heptane consisting of 561 species and 2539 elementary reaction steps. Validation results show acceptable agreement for the autoignition delay time and the PSR calculation in wide parametric ranges of pressure, temperature and equivalence ratio.