Comparative studies on convective heat transfer behaviour of nanofluids under turbulent flow with inserts

Abstract

ABSTRACT In this paper, the thermal performance of novel spiraled rod inserts in the turbulent flow of Al2O3/water, CuO/water, and TiO2/water nanofluids through a circular tube with constant heat flux boundary conditions is compared. The nanofluids used in this study contain particle volume concentrations of 0.25 and 0.5%. According to the study's findings, nanofluids have a greater Nusselt number than deionised water. Among the nanofluids used, CuO nanofluid with a spiraled rod insert of the lesser pitch gives the maximum enhancement in Nusselt number, and the enhancement value is 49.6% for 0.5% volune concentration compared to deionised water. The increase in friction factor for the above condItion is 17.59%. The maximum thermal performance factor value with a pitch of 30 mm spiraled rod insert and 0.5% volume concentration of CuO nanofluids is about 1.41.The novelty of this present study is the simple and easily manufactured inserts used to enhance heat transfer.