Analytical analysis of short contact heat transfer in tube banks has been presented. This analysis is based on the fact that the fluid while flowing across the cylindrical tubes in a bundle is not in continuous contact with the tube surface but comes in contact for a short period only. Therefore, the thermal boundary layer, formed on the tube surface is never fully developed. Consequently, its thickness is so small as compared to the hydrodynamic boundary layer that resistance to heat transfer is confined to a very thin region near the tube surface. This analysis resulted into the following relationship:
Nu = 1.85 (Δ)1/3(Re)1/3(Pr)1/3(EF)1/3
where,
The following correlation was obtained from experimental data for laminar and turbulent flow heat transfer across present tube bank.
cross flow, entrance factor, heat transfer, Nusselt number, void fraction
