• Title/Summary/Keyword: momentum source

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A Study on Daniel Libeskind's architectural contemplation and expressive characteristic (다니엘 리베스킨트의 건축적 사고와 표현 특성에 관한 연구)

  • 이도희
    • Korean Institute of Interior Design Journal
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    • v.13 no.1
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    • pp.30-37
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    • 2004
  • Architect Daniel Libeskind made peculiar works with ‘Jewish Museum’ in Berlin as a momentum in 1989. The concern was concentrated after Libeskind was selected ultimately to the designer of ‘Design for the World Trade Center site’ in February 2003. Especially his works which have been recently accomplished are not the deconstructivism were recognized as unreal drawings and simple studies but they are professing his own peculiar architectural thought. However meanwhile researches about Libeskind have been processed in an architect viewpoint of a deconstructivism tendency, lack of researches to be more various point of view. This study fundamentally is sharing the source with Libeskind's basic idea, as a deconstructivism architect, but not to understand essential concept of decorstructivism which has the philosophy grasps of essence of an object, reconstrues contradiction that the human is simple to prescribe by the language and tries to express in new architectural formative volition. Therefore, the purpose of this study is to grasp of Libeskind's own architectural thought of the essence, consider background becomes the foundation of the architectural thought and peculiarity of the architectural representation.

Numerical simulations of radiative and convective heat transfer in the cylinder of a diesel engine (디이젤엔진내의 복사열전달 효과에 관한 수치해석적 연구)

  • 임승욱;김동우;이준식
    • Journal of the korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.54-64
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    • 1992
  • During combustion process in a diesel engine radiation heat transfer is the same order of magnitude as the convection heat transfer. An approximation of heat and momentum source distributions is applied at a level consistent with those used in modelling the soot distribution and the turbulence instead of modelling the fuel spray and the chemical kinetics. This paper illustrates a use of the third order spherical harmonics approximation to the radiative transfer equation and delta-Eddington approximation to the scattering phase function for droplets in the flow. Results are obtained numerically by a time marching finite difference scheme. This study aims to compare heat transfer with convection heat transfer and to investigate the importance of scattering by fuel droplets and of accounting for spatial variations in the extinction coefficient on the radiative heat flux distributions at the walls of a disc shaped diesel engine.

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Time Mean Drifting Forces on a Cylinder in Water of Finite Depths -Direct Pressure Integration Method- (유한(有限)깊이의 물에 떠있는 주상체(柱狀體)에 작용(作用)하는 시간평균표류력(時間平均漂流力) -직접압력(直接壓力) 적분법(積分法)-)

  • K.P.,Rhee;K.K.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.2
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    • pp.27-34
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    • 1985
  • In this paper, the second order time mean forces acting on the circular cylinder floating on the free surface of a finite water depth are calculated. Under the assumption that fluid is idea and the wave the linear gravity wave, the velocity potential is calculated by the source distribution method, and the second order time mean lateral and vertical drifting forces are calculated by the direct integration of fluid pressures over the immersed body surface. The comparison of the lateral drifting forces with Rhee's results by momentum theorem shows good agreements. And it is shown that the second order time sinkage forces of a floating circular cylinder cross zero for all water depths.

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NUMERICAL STUDY OF CHIP COOLING ENHANCEMENT WITH EVAPORATING MIST FLOW (분무 증발을 이용한 칩 냉각 향상에 대한 수치적 연구)

  • Roh, S.E.;Kim, D.;Son, G.
    • Journal of computational fluids engineering
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    • v.18 no.2
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    • pp.9-16
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    • 2013
  • The heat transfer enhancement of heat sink with mist flow is studied numerically by solving the conservation equations for mass, momentum and energy in the continuous and dispersed phases. A Lagrangian method is used for tracing dispersed water droplets in the heat sink and an Eulerian species transport model for air and steam mixture. The continuous and dispersed phases are interacted with the drag and evaporation source terms. The computed results show that addition of evaporating mist droplets enhances the cooling performance of heat sink significantly.

A Numerical Study of Smoke Movement by Fire In Atrium Space (화재 발생시 연기 거동에 대한 수치해석적 연구 - 아트리움 공간을 중심으로 -)

  • 노재성;유홍선;정연태
    • Journal of the Korean Society of Safety
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    • v.13 no.1
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    • pp.70-76
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    • 1998
  • The smoke filling process for the atrium space containing a fire source is simulated using two types of deterministic fire models : Zone model and Field model. The zone model used is the CFAST(version 1.6) model developed at the Building and Fire Research Laboratories, NIST in the USA. The field model is a self-developed fire field model based on Computational Fluid Dynamics(CFD) theories. This article is focused on finding out the smoke movement and temperature distribution in atrium space which is cubic in shape. A computational procedure for predicting velocity and temperature distribution in fire-induced flow is based on the solution, in finite volume method and non-staggered grid system, of 3-dimensional equations for the conservation of mass, momentum, energy, species and so forth. The fire model i. e. Zone model and Field model predicted similar results for the clear height and the smoke layer temperature.

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Structural Design and Analysis for Small Wind Turbine Blade (초소형 풍력발전용 블레이드에 대한 구조설계 몇 해석)

  • Lee, Seung-Pyo;Kang, Ki-Weon;Chang, Se-Myong;Lee, Jang-Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.288-294
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    • 2010
  • In recent years, wind energy has been the world's fastest growing source of energy. This paper describes the structural design and analysis of composite blade for 2 kW-level HAWT (horizontal axis wind turbine). The aerodynamic design and force, which are required to design and analyze a composite blade structurally, are calculated through BEMT(blade element momentum theory) implemented in public code PROPID. To obtain the equivalent material properties of filament wound composite blades, the rule-of-mixture is applied using the basic material properties of fiber and matrix, respectively. Lay-up sequence, ply thickness and ply angle are designed to satisfy the loading conditions. Structural analysis by using commercial software ABAQUS is performed to compute the displacement and strength ratio of filament wound composite blades.

An Analysis of Heat and Fluid Flow in the Laser Surface Melting with a Deformed Surface. (굴곡의 표면을 가진 금속의 레이저 용융에 대한 열 및 유체유동 해석)

  • Kim, Young-Deuk;Sim, Bok-Cheol;Kim, Woo-Seung
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.139-144
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    • 2003
  • Laser melting problems with deformed substrates are investigated by axisymmetric numerical simulations. Source-based method is used to solve the energy equation, and the momentum equations are solved in the liquid domain with SIMPLER algorithm. Using a laser beam with a top-hat heat flux distribution, this study is performed to examine the effect of surface deformation, beam power density and surface tension force on the melt pool during laser melting. Surface temperature decreases with increasing surface deformation, while surface velocity increases. It is found that surface deformation, beam power density and surface tension force have a very significant effect on heat transfer and fluid flow during laser melting.

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Analysis of Hot Gas Flew Considering Arc-Flow Interaction (아크플라즈마와 유동간의 상호작용을 고려한 열가스 유동 해석)

  • Kim, Hong-Gyu;Park, Gyeong-Yeop;Bae, Chae-Yun;Jo, Gyeong-Yeon;Jeong, Hyeon-Gyo
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.3
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    • pp.107-115
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    • 2002
  • This parer presents the analysis of hot gas flow in puffer-type circuit breakers using FVFLIC method. For the analysis of arc-flow interaction, the flow field is analyzed from the equations of conservation for mass, momentum and energy with the assumption of local thermodynamic equilibrium state. The arc is represented as the energy source term composed of ohmic heating and radiation term in the energy conservation equation. Ohmic heating is computed by the electric field analysis only within the conducting plasma region. An approximate radiation transport model is employed for the evaluation of emission and absorption of the radiation. The analysis method was applied to the real circuit breaker model and simulation results such as pressure rise and arc voltage were compared with the experimental ones.

NUMERICAL IMPLEMENTATION OF THE TWO-DIMENSIONAL INCOMPRESSIBLE NAVIER-STOKES EQUATION

  • CHOI, YONGHO;JEONG, DARAE;LEE, SEUNGGYU;KIM, JUNSEOK
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.19 no.2
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    • pp.103-121
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    • 2015
  • In this paper, we briefly review and describe a projection algorithm for numerically computing the two-dimensional time-dependent incompressible Navier-Stokes equation. The projection method, which was originally introduced by Alexandre Chorin [A.J. Chorin, Numerical solution of the Navier-Stokes equations, Math. Comput., 22 (1968), pp. 745-762], is an effective numerical method for solving time-dependent incompressible fluid flow problems. The key advantage of the projection method is that we do not compute the momentum and the continuity equations at the same time, which is computationally difficult and costly. In the projection method, we compute an intermediate velocity vector field that is then projected onto divergence-free fields to recover the divergence-free velocity. Numerical solutions for flows inside a driven cavity are presented. We also provide the source code for the programs so that interested readers can modify the programs and adapt them for their own purposes.

Analysis of Falling-film Generator in Ammonia-water Absorption System (암모니아-물 흡수식 시스템에서 유하액막식 발생기의 해석)

  • 김병주;손병후;구기갑
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.5
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    • pp.422-430
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    • 2001
  • In the present study, an evaporative generation process of ammonia-water solution film on the vertical plate was analysed. For the utilization of waste heat, hot water of low temperature was used as the heat source. The continuity, momentum, energy and diffusion equations for the solution film and vapor mixture were formulated in integral forms and solved numerically. Counter-current solution-vapor flow resulted in the refrigerant vapor of the higher ammonia concentration than that of co-current flow. Eve the rectification of refrigerant vapor was observed near the inlet of solution film in counter-current flow. For the optimum operation of generator using hot water, numerical experiments, based on the heat exchange and generation efficiencies. revealed the inter-relationships among the Reynolds number of the solution film and hot water, and the length of generator. Enhancement of heat and mass transport in the solution film was found to be very effective for the improvement of generation performance, especially at high solution flow rate.

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