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.

한국 절지동물 연구의 과거 및 현재와 발전방향

이창언,김원,권용정,Lee, Chang-Eon,Kim, Won,Kwon, Yong-Jung 한국동물분류학회 1991 Animal Systematics, Evolution and Diversity Vol.7 No.1

절지동물은 지금까지 전세계적으로 기록된 동물 총 수의 3/4이상을 차지 하고 있으며, 지구상의 거의 모든 서식처에 살고 있다. 그러므로 절지동물은 우리 인간생활과 벌정한 관계를 맺고 었으며, 이에따라 절지동물의 연구는 동서고금을 막론하고 국가적인 차원에서 지원되고 있다. 그러나 우리의 상황은 선진국 에 비하여 상당히 뒤떨어져 있는 바, 보다 체계적인 연구를 바탕으로 순수학문 과 응용분야가 함께 발전할 수 있도록 국가정책의 배려가 절실하게 요구되고 있다. 따라서 본 논문은 이러한 필요성에 입각하여, 절지동물의 대부분을 차지하고 있는 곤충류와 갑각류를 대상으로 하여 한국 절지동물 연구에 관하여 고찰하였다. 과거 및 현재에 관한 논의에서는 한국산 절지동물의 연구사, 국가정책에 이용된 예, 표본의 보존현황 등을 조사하였으며, 연구의 발전방향에 관한 부분 에서는 이러한 과거 및 현재에 대한 조사를 바탕으로 하여 몇가지 중요사항을 논의하였는데, 이에는 범국가적 표본시설의 건립, 자료의 전산화, 연구방법의 체계적 다양화, 해충관리 전략의 확립, 자연보호와 환경관리에의 기여, 실험재료로서의 으용, 국민복지생활 증진을 위한 연구, 전문인력의 양성과 국가적 지원의 대책 등이 포함되어 있다. The arthropods are the most diverse and successful animal group making up more than three quarters of the total animal species. They also live in a great diversity of habitats on the earth. Because of these unavoidable circumstances, the human life has always been affected by them. Therefore, in many countries from the past, governments have supported the studies of the arthropods on the basis of the national policy. However, the present situation of ours is far behind the other advanced contries, Now we urgently need governmental support fro the development of both the basic and the applied fields of arthropod studies in the well organized manner. Facing with this necessity, the present article reviewed the studies of Korean arthopods based on insect and crustacean representing most of the arthopods. Several subjects were reviewed in the section of the past and present studies on Korean arthropods. These are the studies on Korean arthropods in the past and present, their application to the national strategy, and the present condition of curating specimens, etc. From these reviews, several important points were suggested in the section of future plan. These are such subjects as the establishment of national institution for the curation of specimens , computerizing the data, diversification of research techniques, valid strategy concerning the control of harmful contribution to the nature conversation and environmental management , use as a research animal, the enhancement of public welfare, training of specialists, and policies for the national programs.

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.

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.

GT-POWER를 이용한 신형 로터리 엔진의 1D 해석 모델 개발

박영준(Youngjoon Park),박태준(Taejoon Park),이창언(Chang-Eon Lee) 한국자동차공학회 2021 한국 자동차공학회논문집 Vol.29 No.1

In this study, 1D CFD simulation models are developed by using GT-POWER for a new rotary engine, which originated from a three-lobe gerotor pump(GP3 RTE). The unique characteristics of the GP3 rotary engine, such as the effective area variations of intake/exhaust windows and ports, are taken into consideration for the models. The models are compared in order to identify the effects of each parameter, and validated by comparing with the 3D CFD result. The most advanced model predicts the performance of the GP3 RTE in terms of trapped fuel mass, indicated power, indicated efficiency, and fraction of EGR almost the same as the CONVERGE model. The model may be used as a powerful and convenient tool for obtaining basic information on unique behavior and optimizing the design parameters of GP3 RTE without a time-consuming 3D design change.

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.

가스연소분야 신기술 및 기기개발 방안 연구

이창언(Chang-eon Lee),박태준(Taejoon Park),김도현(DoHyun Kim),이중성(Joongsung Lee) 한국가스학회 2016 한국가스학회 학술대회논문집 Vol.2016 No.11