• Title/Summary/Keyword: 전산역학

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CFD Analyses in a Single Cylinder Engine with Experimental Results (단기통 디젤엔진 계측결과와 전산해석)

  • Joo K. J.;Park H. K.
    • 한국전산유체공학회:학술대회논문집
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    • 2002.05a
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    • pp.121-127
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    • 2002
  • The transient flow fields in direct injection engine was analyzed by using the STAR-CD CFD code during the intake/compression processes. The grids are generated by using the IC3M. The CFD results were compared with experimental data. The results showed that the used techniques were well suited for the flow analyses on any internal combustion engines.

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A NUMERICAL ANALYSIS USING CIP METHOD (CIP 방법을 사용한 해석법)

  • Lee, J.H.;Hur, N.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.211-217
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    • 2009
  • The numerical program has been developed for the purpose of the complicate geometries application using CIP method. The non-staggered, non-orthogonal, and unstructured grid system can be also used for the various geometries in the program. For validating CIP solver, the lid-driven cavity flow and solitary wave propagation flow are carried out. Test results show a good agreement with the verified results. The dynamic solver was used for the behavior of moving body. Interface process between the two solvers is introduced. The research was performed on the flow problem around torpedo and log and the flow problem in a tank in order to analyze the three phase flow problem Although the comparison to the verified results was not quantitatively performed, the trend of the results was reasonable.

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DEVELOPMENT OF A HYBRID CFD FRAMEDWORK FOR MULTI-PHENOMENA FLOW ANALYSIS AND DESIGN (다중현상 유동 해석 및 설계를 위한 융복합 프레임웍 개발)

  • Hur, Nahm-Keon
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.517-523
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    • 2010
  • Recently, the rapid evolution of computational fluid dynamics (CFD) has enabled its key role in industries and predictive sciences. From diverse research disciplines, however, are there strong needs for integrated analytical tools for multi-phenomena beyond simple flow simulation. Based on the concurrent simulation of multi-dynamics, multi-phenomena beyond simple flow simulation. Based on the concurrent simulation of multi-dynamics, multi-physics and multi-scale phenomena, the multi-phenomena CFD technology enables us to perform the flow simulation for integrated and complex systems. From the multi-phenomena CFD analysis, the high-precision analytical and predictive capacity can enhance the fast development of industrial technologies. It is also expected to further enhance the applicability of the simulation technique to medical and bio technology, new and renewable energy, nanotechnology, and scientific computing, among others.

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DEVELOPMENT OF CFD PROGRAM BASED ON UNSTRUCTURED GRID SYSTEM (비정렬 기반의 CFD 프로그램 개발)

  • Lee, Jung-Hee;Lee, Sang-Hyuk;Lee, Myung-Sung;Hur, Nahm-Keon
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.524-529
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    • 2010
  • In the present study, a CFD program is developed for the Fluid-Structure Interaction(FSI) analysis. The non-staggered, non-orthogonal, and unstructured grid system was also used to handle the complicated geometries in the program. In order to validate the capabilities of the developed CFD program, various models are investigated by using unstructured and nonorthogonal meshes. The predicted results are a good agreement with analytic solution, experimental data and commercial software. And also PISO algorithm is applied for transient flow analysis. The cyclic boundary condition and baffle cell are developed in order to improve the effectiveness of the calculation for complex geometry.

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NUMERICAL SIMULATION OF PRESSURE CHANGE INSIDE CABIN OF A TRAIN PASSING THROUGH A TUNNEL (터널을 통과하는 열차의 객실 내 압력 변동 해석)

  • Kwon, H.B.;Yun, S.H.;Nam, S.W.
    • Journal of computational fluids engineering
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    • v.17 no.1
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    • pp.23-28
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    • 2012
  • The pressure transient inside the passenger cabin of high-speed train has been simulated using computational fluid dynamics(CFD) based on the axi-symmetric Navier-Stokes equation. The pressure change inside a train have been calculated using first order difference approximation based on a linear equation between the pressure change ratio inside a train and the pressure difference of inside and outside of the train. The numerical results have been assessed for the KTX train passing through a 9km long tunnel of Wonju-Kangneung line at the speed of 250km/h assuming that the train is satisfying the train specification for airtightness required by the regulation.

A Numerical Study of Aerodynamic Characteristics for a Rotating Parachute in Steady Descending Motion (등속도로 하강중인 Rotating Parachute의 공력특성에 관한 수치 해법 연구)

  • Je S. E.;Jung S. G.;Kwag S. H.;Myong R. S.;Cho T. H.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.119-122
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    • 2005
  • In this paper a method for analysing aerodynamic characteristics of a rotating parachute in steady descending motion is presented. Because of a complex geometric configuration of the parachute associated with side vents and discontinuous skirts, special procedure was adopted th handle the geometry in the analysis. A panel method was successfully applied to the present problem and yielded good results using above procedure. A CFD code using the full Navier-Stokes equations was also applied and provided good results. Parachute free drop and wind tunnel tests were performed to determine the fully developed canopy configuration and aerodynamic characteristics. The method can be used for optimizing the parachute size and side vent configurations in the design period.

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A NUMERICAL STUDY ON AERODYNAMIC CHARACTERISTICS OF A ROTATING PARACHUTE IN STEADY DESCENDING MOTION (등속도로 하강중인 회전 낙하산의 공력특성에 관한 수치적 연구)

  • Je S.E.;Jung S.G.;Kwag S.H.;Myong R.S.;Cha T.H.
    • Journal of computational fluids engineering
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    • v.11 no.1 s.32
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    • pp.52-56
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    • 2006
  • In this paper a method for analysing aerodynamic characteristics of a rotating parachute in steady descending motion is presented Because of a complex geometric configuration of the parachute associated with side vents and discontinuous skirts, special procedure was adopted to handle the geometry in the analysis. A panel method was successfully applied to the present problem and yielded good results using above procedure. A CFD code using the full Navier-Stokes equations was also applied and produced good results. Parachute free drop and wind tunnel tests were performed to determine the fully developed canopy configuration and aerodynamic characteristics. The method can be used for optimizing the parachute size and side vent configurations.

Numerical Simulation of Pressure Change inside Cabin of a Train Passing through a Tunnel (터널을 통과하는 열차의 객실 내 압력 변동 해석)

  • Kwon, H.B.;Yoon, S.H.;Nam, S.W.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.337-342
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    • 2011
  • The pressure transient inside the passenger cabin of high-speed train has been simulated using computational fluid dynamics(CFD) based on the axi-symmetric Navier-Stokes equation. The pressure change inside a train have been calculated using first order difference approximation based on a linear equation between the pressure change ratio inside a train and the pressure difference of inside and outside of the train. The numerical results have been assessed for the KTX train passing through a 9km long tunnel of Wonju-Kangneung line at the speed of 250km/h assuming that the train is satisfying the train specification for airtightness required by the regulation.

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ANALYSIS ON THE DYNAMIC STALL OVER AN OSCILLATING AIRFOIL USING TRANSITION TRANSPORT EQUATIONS (천이 전달 방정식을 이용한 진동하는 익형의 동적 실속의 해석)

  • Jeon, S.E.;Sa, J.H.;Park, S.H.;Byun, Y.H.
    • Journal of computational fluids engineering
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    • v.19 no.1
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    • pp.80-86
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    • 2014
  • Numerical investigation on the dynamic stall over an oscillating airfoil is presented. A Reynolds-Averaged Navier-Stokes (RANS) equations are coupled with transition transport equations for the natural transition. Computational results considering the turbulent transition are compared with the fully turbulent computations and the experimental data. Results with transition prediction show closer correlation with the experimental data than those with the fully turbulent assumption, especially in the reattachment region.

A Study on Optimal Aerodynamic Shape of Airfoil using a Genetic Algorithm (유전자 알고리즘을 사용한 공기역학적 Airfoil 형상 최적화)

  • Jung, Sung-Ki;Duong, Hoang Anh;Lee, Young-Min;Je, So-Young;Myong, Rho-Shin;Cho, Tae-Hwan
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.377-380
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    • 2008
  • In this study, an aerodynamic shape optimization system was developed to study the optimal shape of airfoil. The system consists of GA (Genetic Algorithm) and CFD code based on the Navier-Stokes equation. Lift-drag ratio is chosen as the object function and optimization is conducted for PARSEC airfoil with nine design variables, which is very efficient in representing the surface geometry of airfoil.

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