Heat Transfer Enhancement in Circular Tube Flow Using Graphene Oxide Nanofluid and Its Application to Multi-Heat Pipe

Abstract

SummaryThe experimental study is performed to study convective heat transfer behavior of nanoparticles, i.e., graphene oxide (GO) flowing through a horizontal tube heated under constant heat flux condition. Its application to a multi-heat pipe cooling device in the condition of different filling ratio (40%, 60%, 80% and 100%) under constant heat flux conditions is experimentally investigated. It was found that (i) heat transfer enhancement is caused by suspending nanoparticles, so that maximum value of the Nusselt number is over twice than that of the pure working fluid, (ii) the thermal performance of heat pipe increases with increasing the concentration of GO nanoparticles in the base fluid, while the maximum heat transfer enhancement yields at 0.2% volume concentration, (iii) GO/water nanofluid shows lower thermal resistance compared to pure water, (iv) the optimal thermal resistance is obtained at 100% filling charge ratio with 0.2% volume concentration, and (v) heat transfer coefficient of the heat pipe significantly increases with an increase in heat flux and GO nanoparticles concentration.