Enhancement of heat transfer of laminar flow through a circular tube having integral helical rib roughness and fitted with wavy strip inserts

The experimental friction factor and Nusselt number data for laminar flow through a circular duct having integral helical rib roughness and fitted with way strip inserts have been presented. The heat transfer test section was electrically heated and uniform wall heat flux boundary condition was imposed. Friction factor and Nusselt number correlations have been developed by log-linear regression analysis. The performance of the present fin geometry has been evaluated. The major findings of this experimental investigation are that the wavy strip inserts in combination with integral helical rib roughness perform better than the individual enhancement technique acting alone for laminar flow through a circular duct up to a certain range of parameters. (c) 2013 Elsevier Inc. All rights reserved.