Chemical Engineering Research & Design, Vol.85, No.A4, 465-472, 2007
A mechanistic insight of convective heat transfer in turbulent flow in smooth round pipe with a turbulent'scoops' concept
The mechanism of heat transfer from a wall to a fluid as influenced by turbulence is described in line with the classical concept of turbulent bursts. The bursts are viewed as turbulent 'scoops' which scoop the 'lumps' of mass away from the wall region efficiently. The,scoops' are a good proposition leading to a Nusselt correlation formulation which resembles well the Churchill correlation though it has been classified as 'purely empirical' model. The current analysis has given his correlation and the like, an intuitive and physics backing. Three regimes are considered, i.e., purely laminar, transitional (an unsteady flow condition triggered by the scoops) and turbulent regime (where scooping is the main effect). The objective of this study is not at fitting accurately the experimental or numerically computed data already in literature. It is expected to make a contribution to the interpretation of the effect of turbulence on heat (and mass) transfer.