• Title/Summary/Keyword: 부력에 조력하는 유동

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A Numerical Study on Mixed Convection in Boundary Layer Flows over Inclined Surfaces (경사진 평판 주위에서 경계층유동의 혼합대류에 관한 연구)

  • 김동현;최영기
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.3
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    • pp.725-733
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    • 1990
  • An analysis of laminar mixed convection flow adjacent to the inclined flat surface which is subjected to a uniform temperature in a uniform free stream is performed. Nonsimilar boundary layed equation are derived by using the mixed convection parameters such that smooth transition from the purely forced convection limit to the purely free convection limit is possible. The governing equations are solved by a finite difference method using the coupled box scheme of sixth order. Numerical results are presented for prandtl numbers of 0.7 and 7 with the angle of inclination ranging from 0 to 90 degree from the vertical. The velocity distributions for the buoyancy assisting flow exhibit a significant overshoot above the free stream value in the region of intense mixed convection and the velocity field is found to be more sensitive to the buoyancy effect than the temperature field. The separation point near the wall was obtained for the buoyancy opposing flow. The local Nusselt number increases for buoyancy assisting flow and decreases for opposing flow with increasing value of the local Grashoff number in the mixed convection parameter. For large Prandtl number, the Nusselt number and the friction factor decrease significantly near the separation point. Present numerical predictions are in good agreement with recent experimental results by Ramachandran.