Natural Convection in the Annulus between Horizontal Non-Circular Cylinders

수평 비원형이중관 사이의 환상공간에서의 자연대류

  • 배대석 (동아대학교 대학원 기계공학과) ;
  • 권순석 (동아대학교 공과대학 기계공학과)
  • Published : 1989.11.01

Abstract

Laminal natural convection heat transfer in the annulus between isothermal horizontal non-circular cylinders is studied by solving the Navier-Stokes and energy equation using an elliptic numerical procedure. Results are obtained to determine the effects of the diameter ratio($D_o/D_i$) and Rayleigh number on heat transfer. The diameter ratio is varied from 1.5 to 13.0 at Pr=0.7, H/L=1.5 and $10^3{\leqslant}Ra_L{\leqslant}4{\times}10^4$. It is found that the diameter ratio causes a more significant on the local heat transfer coefficient of lower semi-circular cylinder and plate than upper semi-circular cylinder. The mean Nusselt number increases as the diameter ratio and Rayleigh number increase, and is higher than that of the circular annulus with a same wetted perimeter.

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