New insight into the heat transfer and pressure drop correlations for laminar and turbulent flow in a circular tube with a twisted-tape insert: A discriminated dimensional analysis

Abstract

Discriminated dimensional analysis combined with the scale analysis has been implemented to obtain new correlations describing the dimensionless pressure drop as Hagen number and Nusselt number for laminar and turbulent swirl flow in a circular tube with a classical twisted-tape insert. The new insight into the phenomenon revealed that the swirl parameter Swh, as a criterion of similarity, governs the process in the entire region of swirl fluid flow in a circular tube with a classical twisted-tape insert. The validity of the analysis has been demonstrated by an excellent agreement between a large experimental data set for isothermal pressure drop and Nusselt number from many different sources with the predictions of the Hgh+−Swh and Nuh+−Swh correlations.