수치계산을 이용한 LFG 혼합연료의 연소속도 상관식에 관한 연구

이창언,오창보,정익산,Lee, Chang-Eon,O, Chang-Bo,Jeong, Ik-San 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.11

In this study, the burning velocities of LFG and LFG mixed fuels have been numerically determined. C3 reaction mechanism involving 92 species and 621 reactions was adopted in the calculation. The computed burning velocities using C3 mechanism show good agreements with experimental data. Based on numerical results, the maximum burning velocities of LFG and LFG mixed fuels were correlated as a function of CH$_4$ and LFG component percentage at stoichiometric conditions. In addition, the correlations of burning velocities of LFG and LFG mixed fuels were obtained over a wide range of the equivalence ratio. The numerical results are well agreed with the burning velocity correlations. The burning velocity correlations for LFG and LFG mixed fuels suggested in this study can be applied to the practical utilization of LFG.

비정상 CH$_4$/공기 제트 확산화염에 관한 수치모사

이창언,오창보,Lee, Chang-Eon,O, Chang-Bo 대한기계학회 2001 大韓機械學會論文集B Vol.25 No.8

The dynamic structures of unsteady CH$_4$/Air jet diffusion flame with a flame-vortex interaction were numerically investigated. A timed-dependent, axisymmetric computational model and a low mach number approximation were employed in the present calculation. A two-step global reaction mechanism which considers 6 species, was used to calculate the reaction rates. The predicted results including the gravitational effect show that the large outer vortices and the small inner vortices can be well simulated without any additional disturbances near nozzle tip. It was found that the temperature and species concentrations have deviated values even for the same mixture fraction in the flame-vortex interaction region. It was also shown that the flame surface is not deformed by the inner vortex in upstream region, while in downstream region, the flame surface is compressed or stretched by the outer vortex roll-up. The present unsteady jet flame configuration accompanying a flame-vortex interaction is expected to give good implications for the unsteady structures of turbulent flames.

산화제 제어 확산화염의 화염구조 및 NO 생성 특성에 관한 수치해석적 연구

이창언,한지웅,Lee, Chang-Eon,Han, Ji-Ung 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.5

Numerical Study with detailed chemistry has been conducted to investigate the flame structure and NOx formation characteristics in oxygen -enhanced(CH$_4$/O$_2$-$N_2$) and oxygen-enhanced-EGR(CH$_4$/O$_2$-$CO_2$) counter diffusion flame with various strain rates. A small amount of $N_2$is included in oxygen-enhanced-EGR combustion, in order to consider the inevitable $N_2$contamination by $O_2$production process or air infiltration. The results are as follows : In CH$_4$/O$_2$-$CO_2$flame it is very important to adopt a radiation effect precisely because the effect of radiation changes flame structure significantly. In CH$_4$/O$_2$-$N_2$flame special strategy to minimize NO emission is needed because it is very sensitive to a small amount of $N_2$. Special attention is needed on CO emission by flame quenching, because of increased CO concentration. Spatial NO production rate of oxygen-enhanced combustion is different from that of air and oxygen-enhanced-EGR combustion in that thermal mechanism plays a role of destruction as well as production. In case CH$_4$/O$_2$-$CO_2$flame contains more than 40% $CO_2$it is possible to maintain the same EINO as that of CH$_4$/Air flame with accomplishing higher temperature than that of CH$_4$/Air flame. EINO decreases with increasing strain rate, and those effects are augmented in CH$_4$/O$_2$flame.

LFG 혼합연료의 화염 안정화 특성

이창언,황철홍,김선호,Lee, Chang-Eon,Hwang, Cheol-Hong,Kim, Seon-Ho 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.2

In this study, experiments were performed to investigate the characteristics of flame stabilization of the LFG mixing gas. LFG has merely half heating value compared with liquified natural gas but can be greatly utilized as a commercial fuel. In order to use LFG in practical combustors, Webbe Index and heating value of LFG mixing gas were adjusted by mixing LPG with LFG. The comparisons were conducted between CH$_4$and LFG mixing gas for searching the region of flame stabilization based upon the flame blowout at maximum fuel stream velocity. As a result, the flame stability of LFG mixing gas was not improved with that of CH$_4$in non-swirl and weak swirl diffusion flame. However, LFG mixing gas had wide flame stabilization region rather than CH$_4$with increasing ambient flow rate in strong swirl. It was also found that flame stability was affected by included quantity of inert gas such as CO$_2$in the weak swirl but by heating value of fuel in strong swirl.

GT-POWER를 이용한 신형 로터리 엔진의 1D 해석 모델 개발

박영준(Youngjoon Park),박태준(Taejoon Park),이창언(Chang-Eon Lee) 한국연소학회 2020 KOSCOSYMPOSIUM논문집 Vol.2020 No.9

This study develops 1D CFD simulation models for a new rotary engine originated from a three-lobes Gerotor pump(GP3 RTE). The models consider unique characteristics of GP3 RTE such as effective-area variations. The models are compared to identify each parameter effect and validated by comparing to 3D CFD result. The most advanced model well predict the performance indexes. The model may allow as a convenient tool for getting basic informations on optimizing design parameters of GP3 RTE without time-consuming 3D design change.

열교환기 위치에 따른 NOx 및 CO 생성특성

김종민(Jong-Min Kim),이승로(Seungro Lee),금성민(Sung-Min Kum),이호연(Ho-Yeon Lee),윤희중(Hee-Jung Yun),이창언(Chang-Eon Lee) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.38

Recently, strict pollutant regulations of NOx emission and increasing awareness of the environmental damage stimulated interest in research to obtain useful information regarding CO and NOx reductions at the same time. In this study, Premixed flame was experiment to reduce CO and NOx emission level by heat exchanger location in which burner and first heat location distance(L₁) and first and second heat location(L₂) changed. To reduce the NOx emission, first heat exchanger location(L₁) was decided near the flame. After first heat exchanger(L₁) was decided for the optimal NOx emission(about 30 ppm), in order to decide the optimal CO emission(about 30ppm), seocond heat exchanger location(L₂) was tested and decided for several cases. Finally, the optimal location of heat exchanger for minimal CO and NOx emission simultaneously was determined and suggested.

진보진영 내부의 남남갈등과 해소방안

이창언(Lee, Chang Eon) 건국대학교 인문학연구원 2016 통일인문학 Vol.65 No.-

1987년 이후 남남갈등은 분단체제의 극복을 전면화한 NL 세력이 등장하면서 전면화되고 질적으로 다른 차원으로 심화된다. 1980년대 중반 이후 NL 세력 주도로 전개된 통일운동의 이슈는 연방제 통일, 북미 평화협정체결, 상호불가침 선언, 군축과 비핵지대화, 주한미군 철수, 핵무기 철거, 국가보안법 폐지 등이었고 북한바로알기 운동이 진행되면서 보수와의 담론경쟁은 물론 진보진영 내부의 논쟁도 강화된다. 이 글은 남남갈등의 한 축이라고 할 수 있는 진보진영 내부의 갈등의 기원과 현황, 이의 해소 방안을 다룬다. 특히 1987년 이후 남남갈등의 중심축에 있었던 NL 세력을 분석 대상으로 삼는다. 여기서는 북한정권 친화적인 노선에 대한 동화가 가능했던 원인과 과정, 이들의 주장이 가진 빛과 그늘, 그리고 건설적인 차원에서 갈등해소 방안을 제시하고자 한다. 이 글은 진보진영 내부의 남남갈등이 ‘민족해방론’에 내장된 편향성 때문에 진보진영의 대 시민적 정당성을 약화시키고 있다고 본다. 따라서 스스로 자신의 노선과 운동 레퍼토리를 현대적으로 재구성(혁신)하지 않으면 반복될 갈등임을 강조하며 혁신의 과제를 제시하고자 한다. Internal conflict of liberals in South Korea since 1987 has been raised across the board and has been escalated to another level after the National Liberation(NL) force which laid stress on overcoming division of the Korean peninsular appeared. After the mid 1980s, the key issues of the reunification movement led by the NL force were the reunification based on confederate system, the conclusion of a peace treaty between North Korea and the United States, declaration of mutual non aggression, disarmament and denuclearization, withdrawal of the USFK, removal of nuclear weapons, and abolition of the National Security Law. With the public movement to learn North Korea correctly, the argument about those issues amongst the liberals became intensified as well as the NL force"s discourse competition against the conservatives. This article discusses the origins and the present state of the internal conflict in the liberals which has been an axis of the political conflict in South Korea and suggests the solution of the conflict. Most of all, this study analyzed the NL force that has stood in the centric axis of that conflict since 1987. We are here concerned with the cause and the course how the NL force could assimilate the friendly line to the North Korean regime, and the light and shadow of the NL"s position. Then a positive solution to solve the conflict will be presented. This article describes the internal conflict of the liberals caused by the inclination inside the national liberation theory has weakened the liberals" validity in the civil society. Therefore, we suggest the task for innovation, with emphasizing the crisis of the liberals will be repeated unless they reconstruct their movement in modern way.

[일반논문] 한국학생운동의 연구 경향과 과제에 관한 연구 - 연구방법론을 중심으로 -

이창언(Lee Chang-Eon) 역사학연구소 2005 역사연구 Vol.- No.15

기초과학연구논집 - 1991 년 연구실적편 - / 생물학 : 도시발전에 따른 주변지역의 곤충상의 변화

이창언(Chang Eon Lee),박상옥(Sang Ock Park),김희용(Hee Ryong Kim) 대구가톨릭대학교 자연과학연구소 1991 기초과학연구논문집 -연구실적편- Vol.1991 No.-

유신체제 하 학생운동의 집합적 정체성과 저항의 관계

이창언(Lee, Chang-Eon) 역사학연구소 2012 역사연구 Vol.- No.23

This study analyzes the participation of the students into the movement and continuation factor of the resistance under the depressive revitalizing reforms system. It pays attention to the process of conversion as a historical behavior through the interaction in the ‘special place’ and social constitution of the meaning. In the other words, this study investigates how did the student left in the specific historical and social conditions formulate the collective identity and the symbolic phase through putting the meaning to the social events and contradictions and analyzing processes for them. This study emphasizes that the ‘collective identity’ is the changing process of the conventional politics, social value and regulation in the multi organizational field not as a process of straightforward accepting and adaptation of them. It was resulted from the concentration to the diversified mutual interactions of the collective identity and the cultural processes that the binding and mobilization of the students and the creation of the anti hegemony approaches from the viewpoint that they were affected by the existing organization, informal network and own low cultural identity. This study accepts the structural tension, dissatisfaction and the importance of the socio-psychological process besides the role of the movement organization as a strategic behavior. On this matter, this study tries to link to the diversified approaching methods which explain the micro-macro and structure-behavior to improve the analytical explanatory power by the combination of the theories not by the simple description on the data.