• Title/Summary/Keyword: 층류박리거품

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Transition Flow Analysis According to the Change of Reynolds Number for Supersonic Launch Vehicle Fairing Expansion Area (초음속 발사체 선두 팽창부의 레이놀즈수 변화에 따른 천이 유동 해석)

  • Shin, Ho-Cheol;Park, Soo-Hyung;Byun, Yung-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.5
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    • pp.367-375
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    • 2017
  • RANS computational analysis was performed on the head of the launch vehicle including the hammerhead nose pairing in the supersonic regime. The two-dimensional axisymmetric analysis was performed by using laminar, fully turbulent and transition models and compared with the experimental data. It was observed that different flow phenomena occurred depending on the Reynolds number. Under the high Reynolds number condition, the boundary layer becomes turbulent, which is not separated from the surface of the launch vehicle. With the low Reynolds number condition, laminar separation bubble was produced due to the separation and reattachment of the boundary layer on the expansion-compression edge of the hammerhead type nose fairing. The three-dimensional computations with the angle of attack showed a fully detached vortical structure due to the laminar separation bubble. It is proved that the turbulent transition should be considered to predict the separation bubble with the Reynolds number.

A Comparative Study Of Airfoil Flow Considering Transition Phenomenon (천이현상을 고려한 익형유동의 공력특성 비교 연구)

  • Son, Mi-So;Ryu, Dong-Guk;Park, Su-Hyeong
    • Proceeding of EDISON Challenge
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    • 2013.04a
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    • pp.360-364
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    • 2013
  • 본 연구에서는 아음속 저 레이놀즈 수에서 NACA0012에 나타난 층류 박리 거품과 천이유동에 대해 연구하였다. 천이유동조건과 완전난류유동 조건에 따른 EDISON 계산 결과 값과 실험값의 공력계수를 비교하였다. 또한, EDISON 계산 결과 값과 Xfoil을 이용하여 나온 결과 값의 천이점 비교를 통해 Xfoil의 천이 모델과 EDISON 천이 모델간의 차이를 비교하였다.

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The Study of Turbulence Model of Low-Reynolds Number Flow (저 레이놀즈수 유동장에서의 난류모델에 관한 연구)

  • Yoo C.;Lee J. S.;Kim C.;Rho O. H.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.172-177
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    • 2004
  • In the present work, we have interests on the modification of parallel implemented with MPI(Message Passing Interface) programming method, 3-Dimensional, unsteady, incompressible Navier-Stokes equation solver to analyze the low-Reynolds number flow In order to accurate calculation aerodynamic coefficients in low-Reynolds number flow field, we modified the two-equation turbulence model. This paper describes the development and validation of a new two-equation model for the prediction of flow transition. It is based on Mentor's low Reynolds $\kappa-\omega$ model with modifications to include Total Stresses Limitation (TSL) and Separation Transition Trigger (STT)

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