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.

특집 2 : 민주화운동단체에 대한 정치사회학적 고찰 3 ; 한국사회 구조변동과 사회운동의 내적 구성 변화 -한국민주청년단체협의회의 프레임 분쟁과 조직분화를 중심으로

이창언 ( Chang Eon Lee ) 민주화운동기념사업회 한국민주주의연구소 2013 기억과 전망 Vol.0 No.29

본 연구는 1990년대 민족해방운동 계열이 주도한 최대 청년운동조직인 ‘한국민주청년단체협의회(이하 한청협)’의 출범과 분화과정을 고찰하는 것이다. 한청협의 출범과 분화의 과정은 지구적-한국적 전환의 시기, 사회운동의 레퍼토리(repertory)와 그것의 변화과정을 보여준다. 특히 거시 구조적 사회변동, 이에 대한 인식, 해석 틀, 행위전략을 둘러싼 경합을 시계열적으로 추적해 (1) 한청협의 성격과 특징, (2) 내적 긴장과 갈등, (3) 프레임 분쟁에 대한 평가를 중심으로 논의를 진행한다. 이를 바탕으로 개괄적으로나마 현 시기 진보적 정치 · 사회운동의 위기의 원인에 대한 역사적 연원(淵源)도 살펴본다. 한청협 내부의 프레임 분쟁은 정치조직과 통일운동에 대한 첨예한 경합과 각축이었다. 이를 분석하기 위해서는 (1) 기회와 위협에 대한 인식, (2) 한국사회 구조변동, 사회운동의 방향과 과제를 둘러싼 인식의 차이에 대한 이해가 필수적인 전제이다. 한청협의 성장과 분화과정은 NL론의 양면성(성공의 조건과 혁신의 불가능성)을 보여주는 역사적 사건이다. 한청협 프레임 분쟁은 (1) NL론 등장과 확산 이후 NL노선에 대한 최초의 집단적 문제제기이고, (2) 통합 진보당 등 NL주류세력의 운동 패턴과 한계, 그로부터 기인한 현 시기진보정치 위기의 근원을 추적하는 역사적 사건으로서 대단히 중요한 의미가 있다. The purpose of this research is to investigate the establishment and diversification procedure of the Association of Youth Organization for Democracy in Korea(AYOK), which was the largest youth movement organization led by the National Liberation Movement line in 1990s. The overall procedure of establishment and dissolution of AYOK shows repertory of social movement and its changing procedure in the global and Korean transition period. In this research, macroscopic structural social change, recognition of this, interpretation frame, competition over activity strategy are traced in the time series and discussion is proceeded with respect to evaluation of (1) nature and characteristics of AYOK, (2) its internal tension and conflicts, and (3) frame disputes. Based on this, the historical origin of reasons for the crisis of the present progressive political and social movement is investigated at least generally. The frame dispute in AYOK was acute competition and fight over political organization and unification movement. The essential premise for this is the understanding of differences between (1) perceptions on opportunity and threat, and (2) perceptions on structural change of Korean Society, direction and tasks of social movement. The procedure of growth and diversification of AYOK was a historical incident that showed the double-sidedness(condition of success and impossibility of reform) of the NL ideology. The AYOK frame dispute has a very important meaning (1) as the first collective problem posing to the policy line of NL after the advent of NL ideology, and (2) as a historical incident that is traced to be the source of the movement pattern and limitation of the Unified Progressive Party main stream faction and the crisis of present progressive political faction that resulted from it.

[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.