Turbulent-forced convective heat transfer and pressure drop analysis of FE3O4 magnetic nanofluid in a circular microchannel

Abstract

A numerical simulation was accomplished in this study that investigated the turbulent force convective heat transfer and pressure drop in straight circular copper pipe with a hydraulic diameter of 0.0005m and 0.1m in length, as given by Lee and Mudawar [11]. The enhancement of heat transfer for water and nanofluids (Fe3O4) under 100 [W/m2] constant heat flux was applied around the wall of the pipe. In this study, standard k-ɛ turbulence model was employed and was performed at a steady state flow, incompressible turbulent flow, and three-dimensional structure. Various volume concentrations of nanoparticles were conducted in the range of 1% to 15% at constant nanoparticle diameter size, which was 32 nm. The heat transfer enhancement was obtained in the range of Reynolds number from 3000 to 10,000. The results displayed an increase in Reynolds number and volume concentrations, as well as an increase in the Nusselt number. The optimum Nusselt number gained was about 5% to 6% of volume concentration at each Reynolds number tested. Besides, with the increase of Reynolds number, the variation pressure saw a dropped for inlet, whereas an increase in the outlet section. Moreover, the increase in volume concentration also caused a small increment in the pressure drop compared to pure water.