• Title/Summary/Keyword: flux distribution

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The Effects of $CO_2$ on Heat Transfer from Hydrogen Oxygen-enriched Flame (이산화탄소가 수소 산소부화 화염의 열전달에 미치는 영향)

  • Lee, Chang-Yeop;Choi, Joon-Won;Baek, Seung-Wook
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.261-266
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    • 2003
  • An experimental study has been conducted to evaluate the effects of $CO_{2}$ on heat transfer from hydrogen oxygen-enriched flame. Experiments were performed on flames stabilized by a co-flow swirl burner, which mounted on top of the furnace. Five composition conditions of oxidizer were chosen with replacing $N_{2}$ with $CO_{2}$. In a steady state, total and radiative heat flux rates from the flame to the wall of furnace has been measured using heat flux meters. Temperature distribution in furnace also has been checked. Increasing $CO_{2}$ ratio in the oxidizer, the dominant heat transfer mode was changed into convection from radiation. Temperature in the furnace decreased but total heat flux increased.

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Canonical Sampling Method for Initial Conditions for Reactive Flux Calculations Using Nose-Hoover Chains

  • Lee, Song-Hi;Pak, Young-Shang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.4
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    • pp.533-538
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    • 2004
  • Canonical sampling method has been presented to generate the initial conditions for reactive flux studies of organic reactions in water. Velocity Verlet version of Nose-Hoover chain dynamics algorithm has been employed to sample the initial conditions according to canonical distribution. The unstable normal mode of a transition state has been introduced to define a dividing plane separating reactant and product regions in reaction processes. This method has been implemented and tested for the case iels-Alder reaction of methyl vinyl ketone (MVK) and cyclopentadiene (CPD) in water, providing a reliable tool for further reactive flux molecular dynamics studies in condensed media.

A Stator-Separated Axial Flux-Switching Hybrid Excitation Synchronous Machine

  • Liu, Xiping;Zheng, Aihua;Wang, Chen
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.4
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    • pp.399-404
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    • 2012
  • In this paper, a stator-separated axial flux-switching hybrid excitation synchronous machine (SSAFHESM) is presented, of which the structure and operational principle are introduced. The magnetic field distribution under different excited currents is analyzed, and some characteristics including flux-linkage, EMF and field control ability are studied by finite element analysis (FEA). Tests are carried out on a 12/10-pole prototype machine to validate the analysis results, and an excellent agreement is obtained.

Thermoelastic interaction in functionally graded nanobeams subjected to time-dependent heat flux

  • Zenkour, Ashraf M.;Abouelregal, Ahmed E.
    • Steel and Composite Structures
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    • v.18 no.4
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    • pp.909-924
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    • 2015
  • This paper investigates the vibration phenomenon of a nanobeam subjected to a time-dependent heat flux. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the functionally graded (FG) nanobeam is pure ceramic whereas the lower surface is pure metal. A nonlocal generalized thermoelasticity theory with dual-phase-lag (DPL) model is used to solve this problem. The theories of coupled thermoelasticity, generalized thermoelasticity with one relaxation time, and without energy dissipation can extracted as limited and special cases of the present model. An analytical technique based on Laplace transform is used to calculate the variation of deflection and temperature. The inverse of Laplace transforms are computed numerically using Fourier expansion techniques. The effects of the phase-lags (PLs), nonlocal parameter and the angular frequency of oscillation of the heat flux on the lateral vibration, the temperature, and the axial displacement of the nanobeam are studied.

A Study on Transverse Edge Effect in Linear Induction Motor With Sheet Rotor (Sheet Rotor를 가진 직선형 유도전동기의 Transverse Edge Effect에 관한 연구)

  • Yun Jong Lee;Dal Ho Im;Soo Hyun Baek
    • 전기의세계
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    • v.23 no.4
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    • pp.39-45
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    • 1974
  • In most previous research work, the transverse edge effect has been allowed for only by use of a relativity-increase factor. This paper gives a more exact treatment. A two-dimensional-field analysis is presented for the problem of sheet rotor linear induction motor with finite width the method used takes account of flux leakage in the space between the stator and secondary sheet rotor as well as in the secondary itself. Equations are derived for the flux density distribution in the air gap and for the starting face, in each case as a function of stator current. The cross gap flux density peaks towards athe edge of the stator. This phenomena is known as the transverse edge effect. Measurements of the flux density in the air gap and starting force on a linear induction motor with sheet rotor of different width showed a reasonable agreement,suggest that it would be desirable to take into account also, at least for this motor in which severe redistribution occurs.

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In Silico Analysis of Lactic Acid Secretion Metabolism through the Top-down Approach: Effect of Grouping in Enzyme kinetics

  • Jin, Jong-Hwa;Lee, Jin-Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.5
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    • pp.462-469
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    • 2005
  • A top-down approach is known to be a useful and effective technique for the design and analysis of metabolic systems. In this Study, we have constructed a grouped metabolic network for Lactococcus lactis under aerobic conditions using grouped enzyme kinetics. To test the usefulness of grouping work, a non-grouped system and grouped systems were compared quantitatively with each other. Here, grouped Systems were designed as two groups according to the extent of grouping. The overall simulated flux values in grouped and non-grouped models had pretty similar distribution trends, but the details on flux ratio at the pyruvate branch point showed a little difference. This result indicates that our grouping technique can be used as a good model for complicated metabolic networks, however, for detailed analysis of metabolic network, a more robust mechanism Should be considered. In addition to the data for the pyruvate branch point analysis, Some major flux control coefficients were obtained in this research.

Effects of CO2 on Heat Transfer from Oxygen-Enriched Hydrogen Flame (이산화탄소가 수소 산소부화 화염의 열전달에 미치는 영향)

  • Lee, Chang-Yeop;Choi, Joon-Won;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.8 s.227
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    • pp.937-944
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    • 2004
  • An experimental study has been conducted to evaluate the effects of $CO_2$ on heat transfer from oxygen-enriched hydrogen flame. Experiments were performed on flames stabilized by a co-flow swirl burner, which was mounted on top of the furnace. Five different oxidizer compositions were prepared by replacing $N_2$ with $CO_2$. In a steady state, the total as well as radiative heat flux from the flame to the wall of furnace have been measured using a heat flux meter. Temperature distribution in furnace also has been measured and compared. By increasing $CO_2$ proportion in the oxidizer, the convection played a more significant role rather than radiation. Overall temperature in the furnace was seen to be decreased, while the total heat flux has increased.

A Study on the Heat Transfer Characteristics of the Large Dimension Heater Plate for a Semiconductor Process (반도체 표면처리공정용 대면적 히터 플레이트의 열전달 특성에 관한 연구)

  • Lee, Yun-Yong;Kang, Hwan-Kook;Moon, Seok-Hwan
    • Journal of Surface Science and Engineering
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    • v.43 no.6
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    • pp.309-314
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    • 2010
  • The numerical study for the effect of various factors that affect the temperature distribution of the process glass installed above the large rectangular heater plate was carried out. For the calculation, heat flux, distance between heat source and process glass plate, effect of vacuum condition and convection in a chamber were considered as important factors. The results showed that the temperature gradient on the glass was increased at the natural convection because of the buoyancy force increases due to the heated air. Also, the more heat flux and distance between the heater plate and glass increases, the more increasing the temperature gradient was. In the case of isothermal heating wall, the temperature variation was smaller than the uniform heat flux condition.

An Observer-Theoretic Approach to Estimating Neutron Flux and Precursor Spatial Distributions (중성자속과 프리커서의 공간분포 추정을 위한 옵저버 이론 방법)

  • Park, Young-Ho;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • v.22 no.2
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    • pp.139-150
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    • 1990
  • This paper describes a method for estimating the flux and precursor spatial distributions using only limited flux measurements. It is based on the Luenberger observer in control theory, extended to the distributed parameter systems such as the space-time reactor dynamics equation. The results of the application of the method to simple reactor models showed that the flux distribution could be estimated by the observer very efficiently using information from only a few sensors.

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Modeling and Analysis of PMSMs under Inter Turn Short Faults

  • Choi, Jun-Hyuk;Gu, Bon-Gwan;Won, Chung-Yuen
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1243-1250
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    • 2013
  • A model of a permanent magnet synchronous motor (PMSM) with an inter turn short fault is proposed using a deformed flux model. The deformed flux model includes not only the fault winding flux information but also the inductance variation of the healthy winding considering the configuration of the winding distribution. With the deformed flux model and the positive sequence current assumption, the proposed model is derived in the positive and negative sequence synchronous reference frame (SRF). The finite elements method (FEM) simulation is applied to validate the proposed PMSM model with inter turn short fault.