• Title/Summary/Keyword: Local flow analysis

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A Study on the Spatial Configuration of Type of Health Examination Center (건강검진센터의 공간유형과 구조체계에 관한 연구)

  • Song, Seung-Eon;Kim, Suk-Tae
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.399-410
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    • 2012
  • Due to development of modern medical services and economics, people raised expectation and demand about medical services from previous disease treatment to comprehensive health care covering prevention and health care. Responses of each medical facility to these social needs and the evolution of concept of medicine rapidly occur. The health examination centers are being operated with the purpose of health examination and this trend is reflected on several aspects such as the size of the facilities, function and configuration of space in health examination centers. Thus, health examination centers consisting of various space systems appear, but this trend and interpretations are lacking. Therefore, the purpose of this study is to draw trends of system through analysis of types and its evolved space systematic analysis and establish it. Analysis targets were classified into small, medium and large groups by sizes based on number of space and a total of 12 health examination centers in four for each category were selected. As research methods, functional relationship of space was examined through analysis of type in which segmentalized type tools were applied in local units. The flow diagram was established based on direction turning point and was classified into sub-flow and main-flow in local units and the systems between local units were derived. Finally, the results of this study can be summarized as the following three results. 1) The space connection system of health examination center showed four systems such as circulation, independence, continuation, and network. 2) Local type indicators and global type indicators which were evolved more from limitation of type analysis tools in existing research were derived so that more systematic analysis could be made. 3) Network system is distributed approach system and space for each function is formed around public space.

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Analysis of Performance Characteristics by Inner Flow Path of Side Channel Type Ring Blower (사이드 채널형 링블로워의 임펠러 내부 유로에 따른 성능변화 분석)

  • Lee, Kyoung-Yong;Choi, Young-Seok;Jeong, Kyung-Ho;Park, Woon-Jean
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.4
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    • pp.67-71
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    • 2012
  • This study analyzed performance changes by an inner flow path of impeller groove for side channel type ring blower using CFD. Two models have the same side channel and clearance while one has an inner flow path and the other doesn't. To analyze the performance change of a ring blower, overall performance and local flow field were analyzed. For the overall performance, pressure increase and impeller torque were checked under the design flow condition. Under the design flow condition, pressure increase was greater for the model with the inner flow path. The model with the inner flow path showed improved efficiency because the area subject to torque decreased due to the creation of inner flow path. To analyze local flow field, a section was created from the representative location of each impeller groove toward the direction of radius. Inner channel pressure distribution depending on the rotation direction shows that the model with the inner flow path has pressure equilibrium of working fluid through the inner flow path. Velocity distribution of inside impeller groove shows that flow field was coupled and appeared to form an inner wall where the flow field was stabilized.

Iterative global-local approach to consider the local effects in dynamic analysis of beams

  • Erkmen, R. Emre;Afnani, Ashkan
    • Coupled systems mechanics
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    • v.6 no.4
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    • pp.501-522
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    • 2017
  • This paper introduces a numerical procedure to incorporate elasto-plastic local deformation effects in the dynamic analysis of beams. The appealing feature is that simple beam type finite elements can be used for the global model which needs not to be altered by the localized elasto-plastic deformations. An overlapping local sophisticated 2D membrane model replaces the internal forces of the beam elements in the predefined region where the localized deformations take place. An iterative coupling technique is used to perform this replacement. Comparisons with full membrane analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein. In this study, the membrane formulation is able to capture the elasto-plastic material behaviour based on the von Misses yield criterion and the associated flow rule for plane stress. The Newmark time integration method is adopted for the step-by-step dynamic analysis.

An Aerodynamic Performance Analysis of the Low-Speed Airfoils in Seperated Flow Field (박리유동장에서 저속 익형의 공기역학적 성능해석)

  • Yoo, Neung-Soo
    • Journal of Industrial Technology
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    • v.15
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    • pp.153-168
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    • 1995
  • The purpose of this study is to develop a method for predicting the aerodynamic performance of the subsonic airfoils in the 2-dimensional, steady and viscous flow. For this study, the airfoil geometry is specified by adopting the longest chord line system and by considering local surface curvature. In case of the inviscid-incompressible flow, the analysis is accomplished by the linearly varying strength vortex panel method and the Karman-Tsien correction law is applied for the inviscid-compressible flow analysis. The Goradia's integral method and the Truckenbrodt integral method are adopted for the boundary layer analysis of the laminar flow and the turbulent flow respectively. Viscous and inviscid solutions are converged by the Lockheed iterative calculating method using the equivalent airfoil geometry. And the analysis of the seperated flow is performed using the Dvorak and Maskew's method as the basic method. The wake effect is also considered and its geometry expressed by the formula of Summey & Smith when no seperation occurs. A computational efficiency is verified by the comparison of the computational results with experimental data and by the shorter execution time.

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Numerical Methods for Compressible Boundary Flow Stability

  • Dong, Xue-Zhi;Tan, Chun-Qing
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.737-742
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    • 2008
  • Methods for the solution of linear stability for compressible boundary layers are developed. Both the global and local methods for stability analysis are used. Both methods are use in solution of Coutte shear flow and the results are analysis and compare. Some well-known conclusions of Coutte flow are proved by these methods again.

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Analysis of Flow and Bed Change on Hydraulic Structure using CCHE2D : Focusing on Changnyong-Haman (CCHE2D를 이용한 수리구조물에 의한 흐름 및 하상변동 연구 -창녕함안보를 중심으로-)

  • Ahn, Jung Min;Lyu, Siwan
    • Journal of Korea Water Resources Association
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    • v.46 no.7
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    • pp.707-717
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    • 2013
  • Channel-bed of erosion and sedimentation, where eroded bed and bank materials re-deposit through the action of flow, is a natural phenomenon in alluvial systems. Analysis using a numerical model is important to understand the sediment transport mechanism associated with erosion and sedimentation near weirs and other hydraulic structures within riverine systems. The local riverbed change near a hydraulic structure (Changnyong-Haman multi-function weir in Nakdong river) has been analyzed in order to examine the effect of hydraulic structure on local bed change. A 2D numerical model (CCHE-2D) has been implemented to simulate the sedimentation and erosion over a reach (10 km) including the weir. For the calibration and verification of the model, the rainfall data from a real event (Typoon 'Maemi' in 2003) has been used for flow and stage simulation. And the simulated results show a good agreement with the observed data for whole domain. From the result, it was found that the installation and operation of weir can aggravate the local bed change caused from the flow field change and resulting redistribution of sediment.

A Modified Turbulent Porous Modeling for Numerical Analysis (수치해석을 위한 변형된 난류 다공성 모델링)

  • Chung, Kil-Yoan;Lee, Kwan-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.6
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    • pp.875-882
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    • 2002
  • The modeling for turbulent flow through a porous media has not been confirmed because of a undetermined constant which appears in the governing equations. In present study, the turbulent porous modeling based on the local thermal equilibrium has been extended to the turbulent clear flow. A undetermined constant is also suggested by microscopic analysis. The microscopic analysis is performed in the flat tube with micro-channels, and it confirms that the undetermined constant is 0.99. It is shown that the results of the macroscopic analysis using confirmed constant agree well with those of the microscopic analysis with a maximum error of 3.5%.

Evaluation of sloshing resistance performance for LNG carrier insulation system based on fluid-structure interaction analysis

  • Lee, Chi-Seung;Cho, Jin-Rae;Kim, Wha-Soo;Noh, Byeong-Jae;Kim, Myung-Hyun;Lee, Jae-Myung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.1
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    • pp.1-20
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    • 2013
  • In the present paper, the sloshing resistance performance of a huge-size LNG carrier's insulation system is evaluated by the fluid-structure interaction (FSI) analysis. To do this, the global-local analysis which is based on the arbitrary Lagrangian-Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG sloshing of a KC-1 type LNG carrier insulation system. During the global analysis, the sloshing flow and hydrodynamic pressure of internal LNG are analyzed by postulating the flexible insulation system as a rigid body. In addition, during the local analysis, the local hydroelastic response of the LNG carrier insulation system is computed by solving the local hydroelastic model where the entire and flexible insulation system is adopted and the numerical analysis results of the global analysis such as initial and boundary conditions are implemented into the local finite element model. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

Numerical Study for The Critical-Flow-Characteristics of The Pressure Regulator and Considerations as a Pipe Network Element (II);Influence of the Cross-Sectional-Area and Opening Ratio (정압기 임계유동특성 및 배관망해석 요소로서의 고려에 관한 수치해석적 연구(II);단면적 및 개도 변화)

  • Shin, C.H.;Ha, J.M.;Lee, C.G.;Her, J.Y.;Im, J.H.;Joo, W.G.
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1454-1459
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    • 2004
  • The major parameters governing the fluid dynamical and thermo-dynamical behavior in the large pipeline network system are friction loss and the pipeline length. But in local pipeline networks and relatively short distance pipeline system, secondary loss and the considerations of the moving states of the fluid machine are also important. One of the major element in local pressure control system is pressure regulator. It causes the variations of the physical properties in that pipeline system. When it is under working, the accurate analysis of the flow properties is so difficult. In this study, some numerical approaches to investigate the critical-flow-characteristics of the pressure regulator have been done according to the variations of the opening ratio or cross-sectional area and the detail examinations and considerations of the pressure regulator as a pipeline network elements have been carried. Finally the flow-flied distributions and critical-flow-characteristics have been presented in detail and the critical flow phenomena and the relation to the opening ratio or cross-sectional-area ratio have been studied.

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Two-dimensional Heat Conduction and Convective Heat Transfer a Circular Tube in Cross Flow (원관 주위의 2차원 전도열전달과 국소 대류열전달)

  • Lee Euk-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.1
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    • pp.25-33
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    • 2005
  • When a circular tube with uniform heat generation within the wall was placed in a cross flow, heat flows by conduction in the circumferential direction due to the asymmetric nature of the fluid flow around the perimeter of the circular tube The circumferential heat flow affects the wall temperature distribution to such an extent that. in some cases, significantly different results may be obtained for geometrically similar surfaces. In the present investigation, the effect of circumferential wall heat conduction is investigated for forced convection around circular tube in cross flow of air and water Two-dimensional temperature distribution $T_w(r,{\theta})$ is calculated through the numerical analysis. The difference between one-dimensional and two-dimensional solutions is demonstrated on the graph of local heat transfer coefficients. It is observed that the effect of working fluid is very remarkable.