• 제목/요약/키워드: Kinetic Simulation

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${Ni_3}Al-{Ni_3}V$ 준이원계 합금 포함 삼원계 시스템에서의 meso-scale 미세구조의 전산 모사에 관한 연구 (A computer simulation of the peso-scale microstructural evolution in the ternary Ni- ${Ni_3}Al-{Ni_3}V$ system)

  • 박성일;이혁모
    • 한국재료학회지
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    • 제11권11호
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    • pp.947-952
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    • 2001
  • The meso-scale microstructure of the $Ni-Ni_3Al- Ni_3V$ system is crucial to obtain both high strength and high toughness. Its evolution may be predicted with the aid of computer simulation of the compositional separation for heat-treated alloys. In this study, computer simulations of the hypothetical A-B-C ternary system, which is similar to the $Ni-Ni_3Al- Ni_3V$ system in terms of phase equilibria, have been performed using the kinetic modeling. Simulated morphologies were changed with nominal compositions and model parameters. It was showed the current model was useful and the more realistic model was proposed.

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낙석 특성을 고려한 낙석 시뮬레이션 해석 연구 (A Study on the Analysis of Rockfall Simulation using Rockfall Characteristics)

  • 이종현;구호본;박혁진;배규진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.719-724
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    • 2005
  • It conducted an analysis and the research against kinetic energy distribution, velocity and bounce height according to rockfall characteristics using rockfall simulation program in cut-slope. This study considered kinetic energy and bounce height of rockfall for efficient establishment of rockfall protection fencefence that is countermeasure in cut-slope.

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수학적 모델에 의한 유압 재생 브레이크 시스템의 축압기 용량 선정에 관한 연구 (A Study on Capacity Selection of Accumulator by Mathematical Model in Hydraulic Regenerative Brake System)

  • 이재구;함영복;김도태;김성동
    • 한국공작기계학회논문집
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    • 제10권2호
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    • pp.48-55
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    • 2001
  • An accumulator in hydraulic systems stores kinetic energy during braking action, and then that control hasty surge pres-sure. This study suggests a method to select the capacity of accumulator to control surge pressure to a desired degree. The selection method is based upon a trial and error approach and computer simulation. A mathematical dynamic model of the system was derived and the parameters in the model were identified from experimental data. A series of computer simulation were done for the brake action. The results of the simulation work were compared with those of experiments. These results of the computer simular-tion and experiments show that the proposed method can be applied effectively to control the surge pressure of the hydraulic regenerative brake systems.

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유압 재생 브레이크 시스템의 축압기 용량설계에 관한 연구 (A Study on the Capacity Design of Accumulator in Hydraulic Regenerative Brake System)

  • 이재구
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.348-354
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    • 2000
  • An accumulator in hydraulic systems stores kinetic energy during braking action, and then that controls a hasty surge pressure. This study suggests a method ot determine the capacity of the accumulator to control surge pressure to a desired degree. A mathematical dynamic model of the system was derived and the parameters in the model were identified from experimental data. A series of computer simulation were done for the brake action. The results of the simulation work were compared with those of experiments. These results of the computer simulation and experiments shows that the proposed design method of the accumulator was verified in controlling surge pressure of the system.

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낙석 시뮬레이션 해석을 이용한 효율적인 낙석 방지에 대한 연구 (A Study on Efficient Prevention of Rockfall using Rockfall Simulation Program)

  • 이종현;구호본;김진환;손영진
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.581-584
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    • 2008
  • 본 연구에서는 형상과 규모에 따른 낙석의 특성별로 그 운동과 영향 요인을 분석하였다. 선정된 대상 사면에 대해 낙석 시뮬레이션 프로그램을 수행하여 낙석 특성별 운동에너지 분포화 낙하속도, 도약높이 등에 대한 분석과 연구를 수행하였다. 또한, 연구대상 절토사면의 대책 방안인 낙석방지울타리의 효율적인 설치를 위해 낙석의 운동에너지와 도약높이 등을 활용하는 방안을 검토하였다.

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A Kinetic Monte Carlo Simulation of Individual Site Type of Ethylene and α-Olefins Polymerization

  • Zarand, S.M. Ghafelebashi;Shahsavar, S.;Jozaghkar, M.R.
    • 대한화학회지
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    • 제62권3호
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    • pp.191-202
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    • 2018
  • The aim of this work is to study Monte Carlo simulation of ethylene (co)polymerization over Ziegler-Natta catalyst as investigated by Chen et al. The results revealed that the Monte Carlo simulation was similar to sum square error (SSE) model to prediction of stage II and III of polymerization. In the case of activation stage (stage I) both model had slightly deviation from experimental results. The modeling results demonstrated that in homopolymerization, SSE was superior to predict polymerization rate in current stage while for copolymerization, Monte Carlo had preferable prediction. The Monte Carlo simulation approved the SSE results to determine role of each site in total polymerization rate and revealed that homopolymerization rate changed from site to site and order of center was different compared to copolymerization. The polymer yield was reduced by addition of hydrogen amount however there was no specific effect on uptake curve which was predicted by Monte Carlo simulation with good accuracy. In the case of copolymerization it was evolved that monomer chain length and monomer concentration influenced the rate of polymerization as rate of polymerization reduced from 1-hexene to 1-octene and increased when monomer concentration proliferate.

순산소 미분탄 연소 CFD 연구에 사용되는 촤 반응속도 모델의 적절한 사용에 대한 연구 (On the Proper Use of Char Reaction Kinetic Model in CFD Code for Oxy-PC Combustion)

  • 김대희;최상민
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.67-70
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    • 2012
  • Many computational fluid dynamic (CFD) simulations have treated the coal kinetics poorly due to large physical domain sizes and high computational complexity, particularly for the recent oxy-coal boilers. Furthermore, some modelers' lack of understanding of the kinetic rate model seems to worsen the simulation accuracy. This study is to suggest the importance of proper use of single-film global kinetic model generally used in CFD code to describe the oxy-fuel combustion of coal char through simple char burnout calculation.

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충격파 내에서 형성되는 아르곤 기체의 운동 에너지 분포와 속도 분포에 대한 비평형 분자동역학 모의실험 연구 (Nonequilibrium Molecular Dynamics Simulation Study of Kinetic Energy and Velocity Distribution Profiles of Argon Gases in Shock Waves)

  • 황현석;이지혜;권찬호;김홍래;박민규;김성식
    • 한국군사과학기술학회지
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    • 제14권1호
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    • pp.147-153
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    • 2011
  • A series of nonequilibrium molecular dynamics(NEMD) simulations are performed to investigate the kinetic energy and velocity distributions of molecules in shock waves. In the simulations, argon molecules are used as a medium gas through which shock waves are propagating. The kinetic energy distribution profiles reveals that as a strong shock wave whose Mach number is 27.1 is applied, 39.6% of argon molecules inside the shock wave have larger kinetic energy than molecular ionization energy. This indicates that an application of a strong shock wave to argon gas can give rise to an intense light. The velocity distribution profiles in z direction along which shock waves propagate clearly represent two Maxwell-Boltzmann distributions of molecular velocities in two equilibrium regions and one bimodal velocity distribution profile that is attributed to a nonequilibrium region. The peak appearing in the directional temperature in z direction is discussed on a basis of the bimodal velocity distribution in the nonequilibrium region.