THREE DIMENSIONAL MODELING OF NATURAL CONVECTION HEAT TRANSFER FROM A SHORT OR LONG CYLINDER WITH CONSTANT WALL HEAT FLUX
Three dimensional conservation equations for mass,
momentum and energy have been solved numerically to
predict the natural convection flow and temperature field
around a short or long solid horizontal cylinder in air in the laminar range of modified Rayleigh number spanning from
104 to 108. Simulations have been done for L/D in the range of 0.05 ≤ L/D ≤ 20 for solid cylinders suspended in air.
Interesting flow structures around the solid cylinder have
been observed for small and large L/D. It can be found that
Nu for a short cylinder is higher than that of Nu for a long
cylinder in air for all Ra. New correlations for the average Nu have been developed as a function of L/D (0.05 ≤ L/D ≤ 20) and Ra (104 to 108) for the cylinder. The correlations developed are accurate to the level of ±6% which can be readily used in the industry and academics.