Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.
Combined conduction-free convection heat transfer in
vertical eccentric annuli is numerically investigated using a
finite-difference technique. Numerical results, representing the
heat transfer parameters such as annulus walls temperature,
heat flux, and heat absorbed in the developing region of the
annulus, are presented for a Newtonian fluid of Prandtl number
0.7, fluid-annulus radius ratio 0.5, solid-fluid thermal
conductivity ratio 10, inner and outer wall dimensionless
thicknesses 0.1 and 0.2, respectively, and dimensionless
eccentricities 0.1, 0.3, 0.5, and 0.7. The annulus walls are
subjected to thermal boundary conditions, which are obtained
by heating one wall isothermally whereas keeping the other
wall at inlet fluid temperature. In the present paper, the annulus
heights required to achieve thermal full development for
prescribed eccentricities are obtained. Furthermore, the
variation in the height of thermal full development as function
of the geometrical parameter, i.e., eccentricity is also
investigated.