• Title/Summary/Keyword: 전산 유체해석

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Hydrodynamic Masses of HANARO Flow Tubes (하나로 유동관의 동적유체질량)

  • 류정수;김두기
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.4
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    • pp.413-422
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    • 2001
  • In this study, the effect of hydrodynamic masses is investigated in the dynamic characteristics and earthquake response analyses of the submerged HANARO flow tubes. First, the consistent hydrodynamic masses of the surrounding water are obtained by finite element method. Then, modal analyses and response spectrum analyses are performed and verified by comparing the results with those measured from an experiment. Arbitrary cross-sections of submerged structures and boundary conditions of the surrounding fluid can be considered by using the general benefits of a finite element method comparing with the conventional analytical methods. Practical criteria based on parametric studies are proposed to evaluate the dynamic characteristics of HANARO flow tubes including the hydrodynamic masses.

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Numerical Modelling Techniques of VPMM for Manta Type UUV (만타형 UUV의 VPMM 전산해석기법 개발)

  • Sang-Eui Lee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.05a
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    • pp.151-151
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    • 2023
  • An accurate prediction of the hydrodynamic maneuvering darivatives is essential to desing a robust control system of a UUV(unmanned underwater vehicle). Typically, these derivatives were estimated by either the towing tank experiment or semi-empirical methods. With the enhancement of high performance computing capacity, a numerical analysis using computational fluid dynamics has reach the level of experiment. Therefore, the aims of the present research are to numerically develop a computational model for the vertical planar motion mechanism of a UUV and to estimate the hydrodynamics loads in 6-DOF. The target structure of the present study was manta type UUV (12meter length). The numerical model was developed in 1/ 6 model scale. Numerical results were compared with the results of the towing tank experiment for validation. In the present study, a commercial RANS-based viscous solver STARCCM+ (ver 17.06) was used.

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전산유체역학과 유한요소법

  • 손정락
    • Journal of the KSME
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    • v.29 no.4
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    • pp.403-413
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    • 1989
  • 유한요소법의 전산유체 역학분야에 대한 응용현황을 계산방법과 적용례를 중심으로 정리하였다. 유한요소법의 가장 큰 장점은 복잡한 유동영역을 해석하기 위한 불규칙 요소망(unstructured mesh)의 사용이라 볼 수 있으며 적응적 요소망을 이용하여 계산의 정확도를 높일 수 있는 것 또한 강점이라 할 수 있다. 다만 불규칙 요소망 사용으로 인해 수반되는 대수 방정식 계산시간 및 기억용량의 증가는 conjugate gradient 방법 등을 이용하여 반드시 해결되어야만 한다. 지금 까지 유한요소법을 이용한 계산방법을 개발해 오는 과정을 보면 유한차분법에서 오래 전에 개 발된 방법들을 도입한 경우가 많았으며 특히 난류 및 개발된 경우가 많으며 대부분의 경우 이 들을 그대로 도입, 이용하였다. 반대로 최근에 항공기 동체설계 분야를 중심으로 복잡한 형태의 유동영역을 해석이 요구되는 경우 유한차분법, 특히 유한체적법(finite volume method)에 삼각형 유한요소를 이용한 불규칙 요소망을 도입하여 성공적으로 이용하고 있다. 따라서 전산유체 역 학의 발전을 위하여 두 분야의 유기적인 협조가 필요하며 결과적으로 전산유체 역학기법이 완 전히 기계설계의 한 분야로 정립될 수 있도록 많은 노력이 필요하다고 본다.

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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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THE INVESTIGATION FOR UH-60 HOVERING ACOUSTIC NOISE CHARACTERISTIC ANALYSIS BY COMPUTATIONAL AERO-ACOUSTIC METHOD (전산공력소음해석을 통한 UH-60 제자리비행 공력소음 연구)

  • Park, N.E.;Woo, C.H.;Choi, G.M.;Kim, C.H.;Yee, S.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.70-74
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    • 2009
  • The helicopter development technology is improved by the increasing of computing power and advanced test facilities. The increasing efficiency of fuel consuming by the developing of improved lift-to-drag rotor system is the major issue, the noise reduction for ecology(civil area) and increase of survivability to reduce noise detection(battlefield) also are important. This investigation shows the helicopter external noise flight test methods, conventional military helicopter's(UH-60) experimental results and the numerical modeling method for aero-acoustic of rotor blade and the result of CAA(Computational Aero-Acoustic) for main rotor blade.

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AERODYNAMIC ANALYSIS OF A PITCH OSCILLATING MID-SIZED AIRCRAFT (피치 진동하는 중형항공기의 공력 특성 해석)

  • Lee, Yung-Gyo;Kim, Cheol-Wan;Ahn, Seok-Min
    • Journal of computational fluids engineering
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    • v.16 no.1
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    • pp.48-52
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    • 2011
  • Aerodynamic analysis was done for a fuselage and wing configuration of a mid-sized aircraft using unsteady 3-dimensional Navier-Stokes solver. Various turbulent models including a transitional SST were used to observe a dynamic stall as well as cruise characteristics. Also, different mesh moving methods were evaluated. Flow hysteresis which causes dynamic stall was investigated through flow field investigations.

DYNAMIC STALL ANALYSYS OF A MID-SIZED AIRCRAFT (중형항공기 동적 실속 특성 해석)

  • Lee, Yung-Gyo;Kim, Cheol-Wan;Ahn, Seok-Min
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.37-39
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    • 2010
  • Aerodynamic analysis was done for a fuselage and wing configuration of a mid-sized aircraft using 3-dimensional Navier-Stokes solver. Various turbulent models including a transitional SST were implemented to observe a dynamic stall as well as cruise characteristics. Also, different mesh moving methods were evaluated. Flow hysteresis which causes dynamic stall was investigated through flow field investigations.

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