• 제목/요약/키워드: Near-wall viscous sublayer model

검색결과 3건 처리시간 0.018초

유한요소법을 이용한 난류유동해석 (The Turbulent flow analysis by the Finite Element Method)

  • 황상무
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.253-256
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    • 1999
  • The Streamline Upwind Petrov-Galerkin(SUPG) finite element method is used to solve the two-dimensional laminar and turbulent flow. The flow is simulated by averaged Navier-Stokes equations with a penalty function approach and the lograithmic(k-$\varepsilon$) turbulent model is employed to take into account its turbulent behavior. The near-wall viscous sub-layer model is employed to approach the dominant viscous effects in the near wall zones. To find a good-enough initial guess of the Newton-Raphson iteration solving Nonlinear Matrix the Incremental method is considered for momentum and the Incomplete logarithmic turbu-lent equations for Turbulence. The validation of our method is investigated in comparision with published experimental data.

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고체 분말이 부상하는 2상 난류 수직관 유동에 대한 Lumley의 저항감소 모델의 적용 (II) - 열전달 기구 - (Application of Lumley's Drag Reduction Model to Two-Phase Gas-Particl Flow in a Pipe(II) - Mechanism of Heat Transfer-)

  • 한기수;정명균;성형진
    • 대한기계학회논문집
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    • 제14권1호
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    • pp.214-224
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    • 1990
  • 본 연구에서는 현 저자의 이전의 연구를 확장하여 균일한 열유속을 갖는 2상 기체-고체입자 위 방정식에서 축 방향의 열전달은 반경 방향의 열전달보다 작아 무시 하였으며, 복사 열전달은 기체와 입자 사이의 온도 차이가 적어 무시하였다. 방정식 중 $F_{px}$$F_{pr}$ 은 2상 사이의 상호작용에 의한 단위부피당 축방향과 반경방향 의 저항력이며, 수직관의 열전달 특성을 부하도와 상대 입자 크기 $d_{p}$/D를 변화시 켜 가면서 조사하는 것이다.다.

PIV 기법을 이용한 모형철도터널 직관덕트에서 유동 분포 계측 및 수치해석 결과와의 비교분석 (MEASUREMENT OF FLOW DISTRIBUTION IN A STRAIGHT DUCT OF RAILWAY TUNNEL MOCK-UP USING PIV AND COMPARISON WITH NUMERICAL SIMULATION)

  • 장용준;정우성;박일순
    • 한국전산유체공학회지
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    • 제15권3호
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    • pp.39-45
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    • 2010
  • The turbulent flows in a tunnel mock-up($10L{\times}0.5W{\times}0.25H$ m3 : scale reduction 1/20) with rectangular cross section were investigated. The instantaneous velocity fields of Re = 49,029, 89,571 were measured by the 2-D PIV system which is consisted of double pulsed Nd:Yag laser and the tracer particles in the straight-duct mock-up where the flows were fully developed. The mean velocity profiles were taken from the ensemble averages of 1,000 instantaneous velocity fields. Simultaneously, numerical simulations(RANS) were performed to compare with experimental data using STREAM code. Non-linear eddy viscosity model (NLEVM : Abe-Jang-Leschziner Eddy Viscosity Model) was employed to resolve the turbulent flows in the duct. The calculated mean velocity profiles were well compared with PIV results. In the log-law profiles, the experimental data were in good agreement with numerical simulations all the way to the wake region except the viscous sub-layer (near wall region).