Axial heat conduction effects in forced convection along a cylinder

An analytical study is performed to determine the effects of axial heat conduction and transverse curvature on laminar forced convective heat transfer of liquid metals along a circular cylinder. The flow and thermal boundary layers for this problem are nonsimilar, the non-similarity arising both from the transverse curvature xi = (4/R) (νx/u/sub infinity)/sup 1/2/ of the cylindrical surface and from the axial heat conduction effect expressible as Ω = 1/Pe/sub x/, where Pe/sub x/ is the local Peclet number. The governing equations are solved by the local nonsimilarity method in which all the terms in the conservation equations are retained and only terms in the derived subsidiary equations are selectively deleted according to the levels of truncation. Numerical results are presented for liquid metals having representative Prandtl numbers of 0.03, 0.008, and 0.003 over a wide range of xi values from 0 (i.e., a flat plate) to 4.0 and Ω values from 0 (i.e., without axial heat conduction effect) to 0.20. The results indicate that the local surface heat transfer rate increases with an increase in the transverse curvature of the cylindrical surface, an increase in Prandtl number, and an increase in the axial heat conduction parameter or a decrease in Peclet number. (U.S.)