Combined effect of physical properties and convective heat transfer coefficient of nanofluids on their cooling efficiency
2015 (English)In: International Communications in Heat and Mass Transfer, ISSN 0735-1933, E-ISSN 1879-0178, Vol. 68, 32-42 p.Article in journal (Refereed) Published
The advantages of using Al2O3, TiO2, SiO2 and CeO2 nanofluids as coolants have been investigated by analysing the combined effect of nanoparticles on thermophysical properties and heat transfer coefficient. The thermal conductivity and viscosity of these nanofluids were measured at two leading European universities to ensure the accuracy of the results. The thermal conductivity of nanofluids agreed with the prediction of the Maxwell model within +/- 10% even at elevated temperature of 50 oC indicating that the Brownian motion of nanoparticles does not affect thermal conductivity of nanofluids. The viscosity of nanofluids is well correlated by modified Krieger-Dougherty model providing that the effect of nanoparticles aggregation is taken into account. It was found that at the same Reynolds number the advantage of using a nanofluid increases with increasing nanofluid viscosity which is counterintuitive. At the same pumping power nanofluids do not offer any advantage in terms of cooling efficiency over base fluids since the increase in viscosity outweighs the enhancement of thermal conductivity.
Place, publisher, year, edition, pages
2015. Vol. 68, 32-42 p.
IdentifiersURN: urn:nbn:se:kth:diva-159213DOI: 10.1016/j.icheatmasstransfer.2015.08.011ISI: 000365057200006ScopusID: 2-s2.0-84941108099OAI: oai:DiVA.org:kth-159213DiVA: diva2:783320
Updated from "Manuscript" to "Article". QC 201509072015-01-262015-01-262015-12-18Bibliographically approved