• 제목/요약/키워드: 1차 또는 2차 모멘트 닫힘

검색결과 1건 처리시간 0.015초

후방계단유동에 대한 저레이놀즈 수 난류모형의 예측성능에 관한 연구 (The study of predictive performance of low Reynolds number turbulence model in the backward-facing step flow)

  • 김원갑;최영돈
    • 대한기계학회논문집B
    • /
    • 제20권5호
    • /
    • pp.1661-1670
    • /
    • 1996
  • Incompressible flow over a backward-facing step is computed by low Reynolds number turbulence models in order to compare with direct simulation results. In this study, selected low Reynolds number 1st and 2nd (Algebraic Stress Model : ASM) moment closure turbulence models are adopted and compared with each other. Each turbulence model predicts different flow characteristics, different re-attachment point, velocity profiles and Reynolds stress distribution etc. Results by .kappa.-.epsilon. turbulence models indicate that predicted re-attachment lengths are shorter than those by standard model. Turbulent intensity and eddy viscosity by low Reynolds number .kappa.-.epsilon. models are still greater than DNS results. The results by algebraic stress model (ASM) are more reasonable than those by .kappa.-.epsilon. models. The convective scheme is QUICK (Quadratic Upstream Interpolation for Convective Kinematics) and SIMPLE algorithm is adopted. Reynolds number based on step height and inlet free stream velocity is 5100.