Authors
Abstract
Numerical solutions are presented for the transient natural convection heat
transfer problem in horizontal isothermal cylindrical annuli, enclosed in heated
inner and cooled outer cylinders. Solutions for laminar case were obtained within
Grashof number based on the inner diameter which varied from 1x102 to 1x105 in
air. Both vorticity and energy equations were solved using alternating direction
implicit (ADI) method and stream function equation by successive over relaxation
(SOR) method. The structure of fluid flow such as a velocity vector and
temperature distribution as well as Nusselt number were obtained and the effect of
diameter ratio on them was examined. In addition, the Grashof number was
changed with the influence of variation in Prandtle number and diameter ratio. Our
numerical calculation are summarized by Nussult number vs. Grashof number
curves with diameter ratios and Prandtl as a parameter, which serves as a guide to
natural convection heat transfer calculated from annulus. Good agreement with
previous data is obtained.
Keywords
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