Thermohydraulics of laminar flow of viscous oil through a circular tube having axial corrugations and fitted with centre-cleared twisted-tape

The experimental friction factor and Nusselt number data for laminar flow through a circular duct having axial corrugation and fitted with centre-cleared twisted-tape 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 centre-cleared twisted tapes in combination with axial corrugation perform better than the individual enhancement technique acting alone for laminar flow through a circular duct up to a certain amount of centre-clearance.

► Flow in axially corrugated channel with centre-cleared twisted-tape is studied.
► Friction factor and Nusselt number correlations are developed.
► The thermohydraulic performance is evaluated.
► This finned geometry performs significantly better within limits.