An experimental comparison of convective heat transfer and friction factor of Al2O3 nanofluids in a tube with and without butterfly tube inserts, By Ahmad Azari

Research

Title	An experimental comparison of convective heat transfer and friction factor of Al2O3 nanofluids in a tube with and without butterfly tube inserts
Type	Article
Keywords	—
Journal	Journal of the Taiwan Institute of Chemical Engineers
DOI	—
Researchers	Ahmad Azari (First researcher) ,

Abstract

Nanofluidshaveacquiredcomprehensiveattentionduetotheirroleinenhancingtheefficiencyofthermalsystems.ThepresentstudyreportsafurtherenhancementinNusseltnumberalongwiththemodificationofflowsystemstructures,namely,theadditionofbutterflytubeinserts(BTI)withaninclinedangleof90°inatubeatconstantheatfluxconditions.ExperimentsareperformedtodetermineNusseltnumberandthefrictionfactorofAl2O3/waternanofluidupto2.5%nanoparticlevolumeconcentration(NVC)andintheReynoldsnumberrangeof750–8500.ResultsshowedthatbyusingBTI,nanofluidsfrictionfactorincreasedbyanaverage2.6%relativetotheplaintube.Also,NusseltnumberincreasedwithReynoldsandalongthetubeaxisforlaminarregime.Aconsiderableenhancementofabout345%intheNusseltwasobservedat0.027%NVCandRe=1500fortheflowinatubewithitsBTIrelativetoplaintube(PT).A2.5%increaseintheNVCdecreasedNusseltnumberfortheflowinatubewithBTI.Finally,twocorrelationsforthefrictionfactorandNusseltnumberofwaterandaluminananofluidinatubewithBTIbasedonthemeasuredexperimentalvaluesweredeveloped.