Enhancement of heat transfer of laminar flow of viscous oil through a circular tube having integral axial rib roughness and fitted with helical screw-tape inserts

Abstract

The experimental friction factor and Nusselt number data for laminar flow through a circular duct having integral axial rib roughness and fitted with helical screw-tape inserts have been presented. Predictive friction factor and Nusselt number correlations have also been presented. The thermohydraulic performance has been evaluated. The major findings of this experimental investigation are that the helical screw-tape inserts in combination with integral axial rib roughness perform better than the individual enhancement technique acting alone for laminar flow through a circular duct up to a certain value of the fin parameter.