• Title/Summary/Keyword: computational fluids dynamics

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Predicting Execution Times of CFD Solvers for the Metacomputing System on a Supercomputing Environment (슈퍼 컴퓨팅 환경에서 메타 컴퓨터를 위한 전산 유체 해석 프로그램의 수행 시간 예측 도구 개발)

  • Kang Kyung-Woo;Na Seon-Uk
    • 한국전산유체공학회:학술대회논문집
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    • 1999.11a
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    • pp.187-192
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    • 1999
  • A metacomputing system is constructed by integrating the heterogeneous supercomputers at KORDIC supercomputer center. The implementation is directed toward building up an easy-to-use supercomputing environment for Computational Fluid Dynamics (CFD) simulations. The key feature is an automatic resource selection According to the predicted performance, the system assigns the request job to the most suitable resource which satisfies the user's demands. Verification tests are conducted by using example CFD applications. An overview of the system is given and derivation of performance prediction models is described in details. Discussion is made of the test results to illustrate applicability and usefulness of the proposed models.

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State-of-the-Art of WIG(Wing-In-Ground Effect) Ships and Application of the Computational Fluid Dynamics (위그선 연구현황과 전산유체역학의 응용)

  • Kang Kuk-Jin
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.14-19
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    • 2005
  • The paper introduces the state-of-the art of WIG ship and application field of the CFD to WIG ship development. WIG ships are highly efficient and fast transport vehicles which take advantage of benefits of ground effect. Chapter 1 describes the characteristics of WIG ship. Chapter 2 reviews the research works of Russia, German, Chinese, Korea and etc. Chapter 3 explains the kind of WIG ship categorized by the main operational mode and take-off system. Chapter 4 describes about the application field of CFD to WIG ship development procedure.

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RADIATION HEAT TRANSFER IN HORIZONTAL CYLINDRICAL ANNULUS (수평원관 사이 환상유로에서의 복사열전달 연구)

  • Han, C.Y.;Park, E.S.;Jeon, H.Y.;Yu, M.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.75-77
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    • 2011
  • Thermofluid flow analysis is major subject in most computational fluid dynamics applications. Accompanying convective and conductive heat transport phenomena, radiation plays an important role in high temperature operating systems. Cares in which the radiation dominates are found in such systems as boilers, furnaces, rocket engines, etc. In this paper the finite-volume method (FVM) are employed to simulate two-dimensional radiation problems in concentric and eccentric horizontal cylindrical annuli with general body-fitted coordinates. In that case the simplest and intuitive remedies are proposed for mitigation of ray effect.

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A STUDY OF INCOMPRESSIBLE VISCOUS FLOW ANALYSIS BY VORTEX-IN-CELL METHOD (보오텍스 인 셀 방법을 이용한 점성유동해석 연구)

  • Lee, J.H.;Kim, Y.C.;Lee, K.J.;Suh, J.C.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.78-85
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    • 2011
  • The Vortex-In-Cell(VIC) method combined with panel method is applied to the analysis of incompressible unsteady viscous flow. The dynamics of resulting flow is governed by the vorticity transport equation in Lagrangian form with vortex particle representation of the flow field. A regular grid which is independent to the shape of a body is used for numerical evaluation based on immersed boundary technique. With an introduction of this approach, the development and validation of the VIC method is presented with some computational results for incompressible viscous flow around two or three dimensional bodies such as wing section, sphere, finite wing and marine propeller.

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NONLINEAR FLUTTER ANALYSIS USING INVISCID REDUCED ORDER MODELING TECHNIQUE (비점성 저차모델링 기법을 활용한 비선형 플러터 해석)

  • Kim, Y.H.;Kim, D.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.458-464
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    • 2011
  • A new method identifies coupled fluid-structure system with a reduced set of state variables is presented. Assuming that the structural model is known a priori either from an analysis or a test and using linear transformations between structural and aeroelastic states, it is possible to deduce aerodynamic information from sampled time histories of the aeroelastic system. More specifically given a finite set of structural modes the method extracts generalized aerodynamic force matrix corresponding to these mode shapes. Once the aerodynamic forces are known, an aeroelastic reduced-order model can be constructed in discrete-time, state-space format by coupling the structural model and the aerodynamic system. The resulting reduced-order model is suitable for constant Mach, varying density analysis.

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A NUMERICAL SIMULATION OF HYDROGEN DIFFUSION FOR THE HYDROGEN LEAKAGE FROM FCV IN UNDERGROUND PARKING LOT (지하주차장 내 수소연료 자동차의 수소 누설로 인한 수소 확산에 대한 수치해석 연구)

  • Choi, J.;Hur, N.;Lee, E.D.;Lee, K.B.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.477-482
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    • 2011
  • In the present study, the diffusion process of hydrogen leaking from a FCV (Fuel Cell Vehicle) in an underground parking lot was analyzed by numerical simulations in order to assess the risk of a leakage accident. The temporal and spatial changes of the hydrogen concentration as well as the flammable region in the parking lot were predicted numerically. The effects of the leakage flow rate and an additional ventilation fan were investigated to evaluate the ventilation performance in the parking lot to relieve the accumulation of the leaked hydrogen gas. The present numerical analysis can provide useful information such as the distribution of the leaked hydrogen concentration for safety of various hydrogen applications.

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A STUDY FOR FIRE EXTENSION MECHANISM BETWEEN FLOORS IN A RESIDENTIAL BUILDING WITH NUMERICAL MODELING (주거형 빌딩의 층간 화염전이 화재해석 모델링)

  • Ahn, Chan-Sol
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.512-517
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    • 2011
  • This study is intended for validation of numerical modeling of a residential building which is made to simulate a phenomenon of fire extension from floor to floor. A common residential building which has the area of 80m2 each floor and some combustibles were chosen for numerical modeling. The combustible models were verified through comparing results of numerical simulations and real fire tests. For computational analysis, the Fire Dynamics Simulator was used with Large Eddy Simulation model for turbulence. Consequently, fire-intensity was well predicted and flash-over of rooms were successfully estimated.

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Numerical Analysis of Unsteady Cavitating Flow on a Three-dimensional Twisted Hydrofoil (3차원 비틀어진 날개 주위의 비정상 공동 현상에 대한 수치해석)

  • Park, Sun-Ho;Rhee, Shin-Hyung
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.31-40
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    • 2011
  • Unsteady sheet cavitation on a three-dimensional twisted hydrofoil was studied using an unsteady Reynolds-averaged Navier-Stokes equations solver based on a cell-centered finite volume method. As a verification test of the computational method. non-cavitating and cavitating flow over a modified NACA66 foil section was simulated and validated against existing experimental data. The numerical uncertainties of forces and pressure were evaluated for three levels of mesh resolution. The computed pressure on the foil and the cavity shedding behavior were validated by comparing with existing experimental data. The cavity shedding dynamics by re-entrant jets from the end and sides of the cavity were investigated.

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Numerical Analysis on Performance of Dental Air Turbine Handpiece for Various Reflection Angles of Turbine Rotor (터빈 로터 반사각에 따른 의료용 에어터빈 핸드피스의 성능에 관한 수치 해석)

  • Lee, Jeong-Ho;Lee, Sang-Do;Kim, Kui-Soon
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.29-32
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    • 2008
  • Dental high-speed air turbine handpieces have been used as a dental cutting tool in clinical dentistry for over 50 years, yet little study has been reported on their flow and performance analysis. Therefore it is necessary to investigate turbine for the performance improvements of an air turbine handpiece. This paper presents pressure on turbine rotor and flow analysis in air turbine handpiece using CFD (computational fluid dynamics). Characteristics on each flow and pressure for four various reflection angles of turbine rotor are presented, and then performance change is analyzed about air turbine handpieces by CFD results.

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ALE-Based FSI Simulation of Solid Propellant Rocket Interior (ALE 기반의 고체 로켓 내부 유체-구조 연계 해석)

  • Han, Sang-Ho;Choi, H.S.;Min, D.H.;Kim, C.;Hwang, Chan-Gyu
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.510-513
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    • 2008
  • The traditional computational fluid or structure dynamics analysis approaches have contributed to solve many delicate engineering problems. But for the most of recent engineering problems which are influenced by fluid-structure interaction effect strongly, traditional individual approaches have limited analysis abilities for the exact simulation. Owing to above-mentioned reason, nowadays fluid-structure interaction analysis has become a matter of concern and interest. FSI analysis require several unprecedented techniques for the combining individual analysis tool into integrated analysis tool. The Arbitrary Lagrangian-Eulerian(ALE, in short) method is the new description of continum motion,which combines the advantages of the classical kinematical descriptions, i.e. Lagrangian and Eulerian description, while minimizing their respective drawbacks. In this paper, the ALE description is adapted to simulate fluid-structure interaction problems. An automatic re-mesh algorithm and a fluid-structure coupling process are included to analyze the interaction and moving motion during the 2-D axisymmetric solid rocket interior FSI phenomena simulation.

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