• Title/Summary/Keyword: Three-dimensional model

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DEVELOPMENT AND PRELIMINARY ASSESSMENT OF A THREE-DIMENSIONAL THERMAL HYDRAULICS CODE, CUPID

  • Jeong, Jae-Jun;Yoon, Han-Young;Park, Ik-Kyu;Cho, Hyoung-Kyu;Lee, Hee-Dong
    • Nuclear Engineering and Technology
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    • v.42 no.3
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    • pp.279-296
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    • 2010
  • For the analysis of transient two-phase flows in nuclear reactor components, a three-dimensional thermal hydraulics code, named CUPID, has been developed. The CUPID code adopts a two-fluid, three-field model for two-phase flows, and the governing equations were solved over unstructured grids, which are very useful for the analysis of flows in complicated geometries. To obtain numerical solutions, the semi-implicit numerical method for the REALP5 code was modified for an application to unstructured grids, and it has been further improved for enhanced accuracy and fast running. For the verification of the CUPID code, a set of conceptual problems and experiments were simulated. This paper presents the flow model, the numerical solution method, and the results of the preliminary assessment.

Three-Dimensional Analysis of the Shapes of Gathered Skirts (개더스커트 형상프로포션의 3차원적 해석)

  • Lee, Myung-Hee;Jung, Hee-Kyeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.11 s.158
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    • pp.1598-1607
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    • 2006
  • The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.

STUDY ON THERMAL MODELING METHODS OF A CYLINDRICAL GROUND OBJECT CONSIDERING THE SPECTRAL SOLAR RADIATION THROUGH THE ATMOSPHERE

  • Choi Jun-Hyuk;Choi Mi-Na;Gil Tae-Jun;Kim Tae-Kuk
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.205-208
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    • 2005
  • This research is aimed at the development of a software that predicts the surface temperature profiles of three-dimensional objects on the ground considering the spectral solar radiation through the atmosphere. The thermal modelling is essential for identifying the objects on the scenes obtained from the satellites. And the temperature distribution on the objects is necessary to obtain their infrared images in contrast to the background. We developed a software that could be used to model the thermal problems of the ground objects irradiated by the spectral solar radiation. This software can be used to handle the conduction within the object as a one-dimensional mode into the depth or as a three-dimensional mode through the media. LOWTRAN7 is used to model the spectral solar radiation including the direct and diffuse solar radiances. In this paper, temperature distributions on the objects obtained by using the one-dimensional and the three-dimensional thermal models are compared with each other to examine the applicability of the relatively easy-to-apply one-dimensional model.

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Three-dimensional Numerical Modelling of Seawater Circulation of Semi-enclosed Bay with the Flow-control Structures

  • JONG-KYU KIM;TAE-SOON KANG;HEON-TAE KIM
    • Journal of Ocean Engineering and Technology
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    • v.15 no.3
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    • pp.35-42
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    • 2001
  • The characteristics of tidal circulation with the flow-control structures using the three-dimensional numerical model (POM, Princeton Ocean Model) of Chinhae Bay, Korea were investigated. To confirm th efficiencies of flow-control structures, the training wall and submerged training wall were constructed at the mouth and narrow channel in Chinhae Bay. On the basis of the present investigation, the tidal circulation induced by the construction of flow-control structures could enhance the water exchange improvement appropriately. And, th training wall at the central is more dominated than the other structures for the efficient of water exchange. The sites and types of structure and flow patterns seem to be very sensitive in tidal simulation and changes in flow fields.

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Numerical study of turbulent wake flow behind a three-dimensional steep hill

  • Ishihara, Takeshi;Hibi, Kazuki
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.317-328
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    • 2002
  • A numerical investigation on the turbulent flows over a three-dimensional steep hill is presented. The numerical model developed for the present work is based on the finite volume method and the SIMPLE algorithm with a non-staggered grid system. Standard $k-{\varepsilon}$ model and Shih's non-linear model are tested for the validation of the prediction accuracy in the 3D separated flow. Comparisons of the mean velocity and turbulence profiles between the numerical predictions and the measurements show good agreement. The Shih's non-linear model is found to predict mean flow and turbulence better than the Standard $k-{\varepsilon}$. Flow patterns have also been examined to explain the difference in the cavity zone between 2D and 3D hills.

Three-dimensional analysis of the flow through an axial-flow fan (축류송풍기의 삼차원 유동장 해석)

  • Kim, Gwang-Yong;Kim, Jeong-Yeop;Jeong, Deok-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.4
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    • pp.541-550
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    • 1997
  • Computational and experimental investigations on the three-dimensional flowfield through an automotive cooling fan are carried out in this work. Steady, incompressible, three-dimensional, turbulent flow through a rotating axial-flow fan is analyzed with Reynolds averaged Navier-Stokes equations and standard k-.epsilon. turbulence model. The governing equations are discretized with finite-volume approximations in non-orthogonal curvilinear coordinates. Computational static pressures on the casing wall agree well with the experimental data which are measured in this work. And, they are sensitive to the change of tip clearance. The flowfield is not significantly affected by the thickness of the blade. The k-.omega. model gives the static pressure rise on the casing wall which is similar to that with the k-.epsilon. model.

Simulation of Static Characteristics of Railway Vehicle's Airspring (철도차량용 공기 스프링의 정적 특성 시뮬레이션)

  • Heo, Sin;Gu, Jeong-Seo;U, Chang-Su;Kim, Yu-Il
    • 연구논문집
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    • s.26
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    • pp.15-24
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    • 1996
  • In this study, we performed the static analysis of a cord-reinforced rubber airspring and generated the three-dimensional half-symmetry model which use the finite-strain shell elements to model the airbag. the three-dimensional hydrostatic fluid elements to model the air-filled cavity, and the rebar elements to model the multi-ply nylon reinforcement of airbag. In addition, a three-dimensional rigid surface is used to define the contact between the airspring and metal bead. The air inside the airspring cavity has been modeled as a compressible fluid satisfying the ideal gas law. The conclusions of this study are as follows. 1) In the pressurization step of analysis, we could predict the change of vertical reaction force, cavity volume and pressure within the airspring. 2) In the second step of analyzing vertical static stiffness, the increase of the vertical load increases the vertical stiffness. 3) In case of changing the angle of nylon cord, the increase the angle of nylon cord increases the vertical stiffness.

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Review on Discrete, Appraisal, and Dimensional Models of Emotion (정서의 심리적 모델: 개별 정서 모델, 평가 모델, 차원 모델을 중심으로)

  • Sohn, Jin-Hun
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.179-186
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    • 2011
  • Objective: This study is to review three representative psychological perspectives that explain scientific construct of emotion, that are the discrete emotion model, appraisal model, and dimensional model. Background: To develop emotion sensitive interface is the fusion area of emotion and scientific technology, it is necessary to have a balanced mixture of both the scientific theory of emotion and practical engineering technology. Extensional theories of the emotional structure can provide engineers with relevant knowledge in functional application of the systems. Method: To achieve this purpose, firstly, literature review on the basic emotion model and the circuit model of discrete emotion model as well as representative theories was done. Secondly, review on the classical and modern theories of the appraisal model emphasizing cognitive appraisal in emotion provoking events was conducted. Lastly, a review on dimensional theories describing emotion by dimensions and representative theories was conducted. Results: The paper compared the three models based on the prime points of the each model. In addition, this paper also made a comment on a need for a comprehensive model an alternative to each model, which is componential model by Scherer(2001) describing numerous emotional aspects. Conclusion: However, this review suggests a need for an evolved comprehensive model taking consideration of social context effect and discrete neural circuit while pinpointing the limitation of componential model. Application: Insight obtained by extensive scientific research in human emotion can be valuable in development of emotion sensitive interface and emotion recognition technology.

Three-Dimensional Time Varing Magnetic Field Analysis: Using E-$\Omega$ Method (E-$\Omega$ 법을 이용한 3차익 교류 자장 해석)

  • Kim, Dong-Soo;Han, Song-Yup
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.49-52
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    • 1989
  • Some limits are in two-dimensional analysis by finite element method to electromagnetic machine having finite dimension. Therefore three-dimensional analysis by finite element method, which are modeling original form of models are needed in order to gain accurate solutions. This paper present three-dimensional time varing magnetic field analysis method using electric field E and magnetic scarlar potential $\Omega$, and examine sample model.

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Study on optimization technique for the design of ventilation system of subway (지하철 환기시스템의 최적화에 관한 연구)

  • 김광용;조재형;리쉬밍;양태윤
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.5
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    • pp.630-639
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    • 1998
  • The present research aimed at development of a computer code for the optimal design of ventilation system based on one-dimensional analysis of the air flow. Model experiment and three-dimensional flow analysis have been implemented to determine loss coefficients that were needed for the optimization technique. A research on optimum shape of ventilation shaft has been also carried out through the three-dimensional analysis of the flow.

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