Comparative thermohydraulic analysis of perforated wavy and twisted tape inserts in a tubular heat exchanger using graphene-water nanofluid: An experimental study

Abstract

The current work experimentally examines the thermohydraulic performance of wavy and twisted tape inserts. The study used water and graphene-water NF at weight concentrations of 0.05%, 0.10%, and 0.15% in the Reynolds number range of 4000–18,000. The insert analysis is conducted using a single-pipe tubular heat exchanger with a constant heat flux. The wavy and twisted tapes with identical pitch ratios of 3, 4.5, and 6 were compared to a center circular perforation of 5 mm. The analysis found that wavy tape outperformed the twisted tape insert. Graphene water outperforms water for heat transfer, and increasing the nanoparticle concentration boosts thermal performance substantially. The lowest pitch ratio insert’s central circular perforation wavy tape offers the maximum thermal performance factor of 1.77 at 4000 Reynolds number. The friction factor and Nusselt number rise with nanofluid concentration and perforation inclusion. The average thermal performance increases by employing nanofluid compared to water for plain tube, wavy tape, and twisted tape at the lowest pitch ratio and the maximum concentration of graphene-water nanofluid is 11.67%, 46.22%, and 44.48%, respectively, in the 4000–18,000 Reynolds number range.