• 제목/요약/키워드: Production Mechanism

검색결과 2,131건 처리시간 0.034초

가스 연료의 연소 방식에 따른 NOx 생성 특성 (NOx Formation Characteristics in Diffusion, Partial Premixed and Premixed Jet flame)

  • 최영호;이창언
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
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    • pp.155-164
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    • 1998
  • Numerical analysis was performed with multicomponent transport properties and detailed reaction mechanisms for axisymetric 2-D CH4 jet diffusion, partial premixed, premixed flame. Calculations were carried out twice with C2-Full Mechanism including prompt NO reaction in addition to the above C2-Thermal NO Mechanism. The role of thermal NO mechanism and prompt NO mechanism on each flame's NO production is investigated by using the numerical result. The NOx production of each flame were evaluated Quantitatively in terms of the NOx emission index

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CH4/CHF3/Air 예혼합 화염의 축소 반응 메카니즘 개발 (The Development of a Short Reaction Mechanism for Premixed CH4/CHF3/Air Flames)

  • 이기용
    • 한국연소학회지
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    • 제19권1호
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    • pp.39-44
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    • 2014
  • A short reaction mechanism for premixed $CH_4/CHF_3/Air$ flames was developed with a reduction method of the combined application of simulation error minimization (SEM) which included connectivity method and principal component analysis. It consisted of 43 species and 403 elementary reactions at the condition of less than 5% of maximum error. The calculation time operated with a short mechanism was over 5 times faster than one with a detailed reaction mechanism. Good agreement was found between the flame speeds calculated by the short reaction mechanism and those by the detailed reaction mechanism for the entire range of $CHF_3/CH_4$ mole ratios and equivalence ratios. In addition excellent agreements were determined for the profiles of temperature, species concentration, and the production rates of the various species. So the short reaction mechanism was able to accurately predict the flame structure for premixed $CH_4/CHF_3/Air$ flames.

Design of a VCM actuator for dual servo system

  • Choi, Hyeun-Seok;Han, Chang-Soo;Kim, Seung-Soo;Kim, Eung-Zu;Choi, Tae-Hoon;Na, Kyoung-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.301-306
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    • 2004
  • In this study, Dual servo mechanism with VCM(Voice Coil Motor) and PZT is designed for a high precision force and position control. We designed the VCM actuator and dual servo mechanism with leaf spring. VCM actuators, with their high linearity, simple structure, low weight, and high efficiency, are increasingly being used in micro-positioning applications. There are many kinds of VCM with a structure. VCM actuators are divided into two types by moving parts. One is moving magnet type and the other moving coil type. We described the properties of these two types of VCM. Design parameters of VCM are defined through the FEM simulation analysis of magnetic field and dynamic model of dual servo mechanism. These researches help to for decreasing loss in the air gap of VCM. We present dual servo mechanism is effective mechanism for a force control in hi h precision, properties of designed VCM.

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1,2 Dichloroethane의 열분해에 대한 수치해석 (Numerical Simulations of the Pyrolysis of 1,2 Dichloroethane)

  • 이기용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집D
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    • pp.697-702
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    • 2001
  • Numerical simulations of 1,2 dichloroethane(EDC) pyrolysis are conducted to understand the process on the production of the vinyl chloride monomer(VCM) and by-products. A chemical kinetic mechanism is developed, the adopted scheme involving 44 gas-phase species and 260 elementary forward and backward reactions. Detailed sensitivity analyses and the rates of production analysis are performed on each of the reactions and the various species, respectively. The concentrations of EDC, VCM, and HCI predicted by this mechanism are in good agreement with those deduced from experiments of commercial and laboratory scale. The mechanism is found to accurately predict the VCM yield and the production of by-products by varying the ranges of pyrolysis temperature, residence time, and pressure which impact on the pyrolysis of 1,2 dichloroethane. The influence of reactions related to H atom on the relative sensitivity of EDC becomes important as the residence time increases. The pyrolysis of EDC mainly occurs through $C_{2}H_{4}Cl_{2}+Cl=CH_{2}ClCHCl$.

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팽윤 전분을 기질로 한 Cyclodextrin Glucanotransferase의 Cyclodextrin 생성반응 기작 (Reaction Mechanixm of Cyclodextrin formation from Swollen Extrusion Starch by cyclocextrin Glucanotransferase)

  • 이용현;조명진;박동찬
    • 한국미생물·생명공학회지
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    • 제23권4호
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    • pp.416-424
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    • 1995
  • Mechanism of the cyclodextrin (CD) production reaction by cyclodextrin glucanotransferase (CGTase) using swollen extrusion starch as substrate was investigated emphasizing the structural features of starch granule. The degree of gelatinization was identified to be the most representative structural characteristic of swollen starch. The most suitable degree of gelatinization of swollen starch for CD production was around 63.52%. The structural transformation of starch granule during enzyme reaction was also followed by measuring the changes of the degree of gelatinization, microcrystallinity, and accessible and inaccessible portion to CGTase action of residual swollen starch. The adsorption phenomenon of CGTase to swollen starch was also examined under various conditions. The inhibition mechanism of CGTase by various CDs was identified to be competitive, most severely by a-CD. The mechanism elucidated will be used for development of a kinetic model describes CD production reaction in heterogeneous enzyme reaction system utilizing swollen extrusion starch.

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Numerical Simulations of the Pyrolysis of 1, 2 Dichloroethane

  • Lee, Ki-Yong
    • Journal of Mechanical Science and Technology
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    • 제16권1호
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    • pp.102-108
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    • 2002
  • Numerical simulations of 1, 2 dichloroethane(EDC) pyrolyisis are conducted to understand the process in the production of the vinyl chloride monomer (VCM) and by-products. A chemical kinetic mechanism Is developed, with the adopted scheme involving 44 gas-phase species and 260 elementary forward and backward reactions. Detailed sensitivity analyses and the rates of production analysis are performed on each of the reactions and the various species, respectively. The concentrations of EDC, VCM, and HCI predicted by this mechanism are in good agreement with those deduced from experiments of commercial and laboratory scale. The mechanism is found to accurately predict the EDC yield an(1 the production of by-products by varying the ranges of pyrolysis temperature, residence time, and pressure which impact on the pyrolysis of 1, 2 dichloroethane. The influence of reactions related to H atom on the relative sensitivity of EDC becomes important as the residence time increases. The pyrolysis of EDC mainly occurs through C$_2$H$_4$Cl$_2$+Cl=CH$_2$CICHI+HCI.

최적 보행 동작 구현을 위한 시뮬레이션 기반 Jansen Mechanism 활용 보행 로봇 설계 및 구현. (Simulation-based Jansen mechanism utilizing walking robot of the design and implementation in order to implement the best walking movement.)

  • 김희찬;김승하
    • EDISON SW 활용 경진대회 논문집
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    • 제5회(2016년)
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    • pp.467-468
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    • 2016
  • The importance of the recent manufacturing industry have been made to invest in a lot of assistance and human resource development at the national dimension in which to rise again. However Learned in actual school education kinetic, and the use to how product design structural knowledge, Often it feels vague unlikely whether it is possible to derive an optimal product. In this study, by using the simulation-based Jansen Mechanism designed a walking robot, after optimization of the numerical consideration when designing for optimum walking motion, through simulation through the actual production resulting numerical information is examined whether valid. In addition, through the actual production was walking robot, to verify the validity of the simulation-based design.

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CONWIP 통제방식에 의해 운영되는 다품목 생산시스템의 성능평가 (Performance Evaluation of a Multi - Item Production System Operated by the CONWIP Control Mechanism)

  • 박찬우;이효성;김창곤
    • 대한산업공학회지
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    • 제28권1호
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    • pp.1-13
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    • 2002
  • We study a multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations. The production of each component is operated by the CONWIP control mechanism. To analyse this system, we propose an approximation method based on aggregation method. In application of the aggregation method, a product-form approximation technique as well as a matrix-geometric method is used. Comparisons with simulation show that the approximation method provides fairly good results.

강관 적층용접부 잔류응력의 생성기구 (Production Mechanism of Residual Stress Generated by Multi-Pass Welding of the steel Pipe)

  • 장경호;양성철;강재훈
    • 한국강구조학회 논문집
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    • 제13권4호
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    • pp.327-335
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    • 2001
  • 강관 적층용접부에서 발생하는 잔류응력의 특징과 생성 메커니즘을 밝히기 위해 유한요소법을 이용한 3차원 열탄소성 해석을 수행하였다. 용접에 의해 강관을 접합할 때, 원주방향잔류응력과 두께방향잔류응력은 강관 내 외부에서 모두 접합부에서 인장응력이 발생하고, 길이방향잔류응력은 강관 내무에서 인장응력, 외부에서 압축응력이 발생된다. 또한 강관 적층 용접부의 잔류응력 생성기구를 명확히 하였다. 그 결과, 강관의 용접에 의한 잔류응력은 열응력에 의해 발생 할 뿐만 아니라, 강관의 기하학적 형상변화에 의한 영향도 받는다는 것을 밝혔다. 그리고, 용접조건과 강관의 제원이 달라질 경우에도 잔류응력 생성기구가 변함이 없음을 밝혔다.

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Sensitivity of Ozone Concentrations to Initial Concentrations Applying the Carbon Bond Mechanism IV

  • Lee, Hwa-Woon;Kim, Heon-Sook;Oh, Eun-Joo;Kim, Yeon-Hee
    • 한국환경과학회지
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    • 제12권11호
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    • pp.1159-1165
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    • 2003
  • The Carbon Bond Mechanism IV has been developed for use in urban- and regional-scale oxidant models. The photochemical mechanism, CBM4, contains extensive improvements to earlier carbon bond mechanisms in the chemical representations of aromatics, biogenic hydrocarbons, peroxyacetyl nitartes, and formaldehyde. Ozone is produced mainly by nitrogen oxides and hydrocarbon. By altering the initial concentrations of the mechanism, an analysis of the sensitivity of ozone concentrations to VOC/NO$\_$x/ ratios and VOC composition is conducted in this one-dimensional mechanism. Note that it is considered a chemical mechanism in order to understand the photochemical reactions within this mechanism. It analyzed the results of these simulations by applying a NO$\_$x/-sensitive and a VOC-sensitive regime. These sensitivity regimes are changed to match the relative contribution of VOC and NO$\_$x/ concentrations to ozone production in simulations of two sets.