• 공업화학
• /
• 제22권4호
• /
• pp.433-438
• /
• 2011

본 연구에서는 SNCR 공정에서 온도, NSR, 산소 농도가 질소산화물 제거 효율에 미치는 영향을 실험과 CHEMKIN-II 프로그램을 사용하여 수치적으로 조사하였다. 산소가 없는 조건에서 NO 제거 효율은 반응기 온도에 따라 증가하였다. 반면 산소농도가 4%일 때, NO 제거 효율은 $900{\sim}950^{\circ}C$에서 최대를 나타내었다. 산소의 존재는 저온에서 NO 제거를 증가시키는 것으로 나타났다. 산소농도와 무관하게 NO 제거 효율은 NSR에 따라 증가하였다. CHEMKIN-II에 의해 예측된 NO 제거 효율의 온도와 NSR-의존성은 실험결과와 유사하였다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
• /
• pp.105-106
• /
• 2012

This study is numerical analysis about optimal conditions of GDICI (gasoline direct injection compression ignition) engine operation using intake preheating. Numerical modeling was performed by using the KIVA-3V Release2 code integrated Chemkin chemistry solver II. For validation of numerical model, experiments were performed on a single-cylinder engine. Throughout the numerical simulations under variable conditions, the ranges of optimal conditions were found.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
• /
• pp.377-380
• /
• 2005

산소 및 공기와 반응시 크랙된 JP-7 연료의 점화 특성에 관한 연구를 넓은 범위의 압력(1-20atm)과 온도(1200-2000K), 당량비(0.5-1.5)에 대해서 수행하였다. Chemkin-II Package와 최소 자승법을 이용하여 $\tau=Aexp(E/RT)[F]^{a}[O_2]^{b}$형태로 점화 지연시간을 계산하고 각 변수 사이의 상호관계를 검증하였다. 크랙된 JP-7 연료에서 $C_3$ 탄화수소 계열 성분의 영향을 두 가지 다른 크랙된 JP-7연료의 조성에 대하여 점화지연 시간을 비교하였으며, 액체 JP-7 연료의 점화 지연 시간과도 비교하여 보았다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.89-92
• /
• 2004

This work describes a model development and numerical simulation of detailed combustion mechanisms of RDX/GAP/BTIN propellants. The analysis is based on the conservation equations of mass, energy, and species concentrations for both the condensed and gas phases, and takes into account finite-rate chemical kinetics and variable thermophysical properties. The model has been applied to study the combustion wave structures and burning characteristics of RDX/GAP/BTIN propellants over a broad range of pressures. Reasonably good agreement is achieved between the calculated and measured burning rate at atmospheric pressure. But the model calculation does not result in dark zone experimentally observed.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
• /
• pp.109-112
• /
• 2015

This article describes a cellular instability and laminar burning velocity of simulated synthetic natural gas(SNG) including 3% hydrogen. In this study, experimental apparatus is employed using cylindrical bomb combustor, and investigation is carried out with high speed camera and Schlieren system. The cellular instability is caused by the buoyancy, hydrodynamic instability. Unstretched burning velocity can be determined by extrapolated stretch rate of zero point from measured results. These results were also compared with numerical calculation by Chemkin package with GRI 3.0, USC-II, WANG, C3 Fuel mechanism. As an experimental conditions, equivalence ratios was adjusted from 0.8 to 1.3. From results of this work, the one was found that the cellular instability has occurred by effect of thermal expansion rate and flame thickness. As the other results, unstretched laminar burning velocity was best coincided with GRI 3.0 mechanism.

• 한국수소및신에너지학회논문집
• /
• 제34권6호
• /
• pp.748-757
• /
• 2023

Numerical analysis was conducted to confirm the characteristics of extinction behavior in NH₃/CH₄ counterflow symmetrical flames. Numerical simulations were run on CHEMKIN-PRO, using the OPPDIF code, with Okafor's mechanisms, which had the lowest error rate compared to Colson's experimental data in the our previous part I study. The chemical interactions of merged flames were examined by analyzing the production rate of major chemical species and key radicals with the volume fractional percentage of ammonia and global strain rate. The interaction phenomenon of the flames could be identified by observing the main chemical reaction path of the merged flames at the stagnation plane.

• 한국연소학회지
• /
• 제10권3호
• /
• pp.10-16
• /
• 2005

Detailed flame structures of the counterflow flames of $CH_4/Air$ formed with $CO_2$ and $H_2O$ addition are studied numerically. The detailed chemical reactions are modeled by using the OPPDIF and CHEMKIN-II code. Only the $CO_2$ and $H_2O$ are assumed to participate in radiative heat transfer while all other gases are assumed to be transparent. The discrete ordinates method(DOM) and the narrow band based WSGGM with a gray gas regrouping technique(WSGGM-RG) are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the counter flow flames. The results compared with the SNB model show that the WSGGM-RG is successful in modeling the counterflow flames with non-gray gas mixture. The numerical results show that the addition of $CO_2$ and $H_2O$ to the oxidant nozzle lowers the peak temperature and the NO concentration in flame.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
• /
• pp.117-128
• /
• 1999

The removal of nitrogen oxides(NOx) from $N_{2}/O_{2}$ gas using a pulsed corona discharge was investigated as a function of the reduced electric field(E/N) and the energy density(J/L). A kinetic model was developed to characterize the chemical reactions taking place in a pulsed corona discharge reactor. The model calculates the fractional concentrations of radical species at each pulse-on period and utilizes the radicals to remove NOx for the subsequent pulse-off period. Electron collision reaction data are calculated using ELENDIF program to solve Boltzmann equation for electron energy distribution function, and the subsequent chemical reactions are calculated using CHEMKIN-II program to solve stiff ODE(ordinary differential equation) problems for species concentrations. The corona discharge energy per pulse and the time-space averaged E/N were obtained by fitting the model to experimental data. The model calculation shows good agreement with the experimental data, and predicts the formation of other species such as $NO_{2}$, $O_{3}$ and $N_{2}O$.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
• /
• pp.215-218
• /
• 2012

In this study, syngas laminar burning velocities with various hydrogen contents were studied using both experimental measurements and kinetic simulations. The laminar burning velocities were measured by the angle method of Bunsen flame configuration and the numerical calculations including burning velocities were made using CHEMKIN Package with USC-Mech II. A large range of syngas mixture compositions such as 10:90%, 25:75%, 50:50%, 75:25% and equivalence ratio from lean condition of 0.5 to rich condition of 5.0 have been conducted. The experimental results of burning velocity were in good agreement with previous other research data and numerical simulation. Also, it was shown that the experimental measurements of laminar burning velocity linearly increased with the increasing of $H_2$ content although the flame speed of hydrogen is faster about ten times than carbon monoxide. This phenomenon is attributed to the rapid production of the hydrogen related radicals such as H and OH at the early stage of combustion, which is confirmed the linear increasing of radical concentrations on kinetic simulation.

• 한국자동차공학회논문집
• /
• 제8권5호
• /
• pp.67-77
• /
• 2000

Investigated was the effect of propene(C3H6) on the NO-NO2 conversion in dry exhaust gases from lean burn engine using a pulsed corona discharge. A kinetic model was developed to characterize the plasma chemistry in simulated exhausts containing propene. The model uses ELENDIF program to solve Boltzmann equation for electron energy distribution function, and CHEMKIN-II program to solve stiff ODE(ordinary differential equation) problems for species concentrations. The corona discharge energy per pulse and the time-space averaged E/N were obtained by fitting the model to experimental data. The model calculation shows good agreement for NO and NO2 concentrations with the experimental data, and predicts the formation of byproducts such as CH2O, CH3HCO, CO AND CH3NO2 Propene enhances the NOx conversion enormously at lower energy density and the NOx conversion increases with the increase of initial propene and oxygen concentration, and temperature.