Forced convective and nucleate flow boiling heat transfer to alumina nanofluids

Abstract

A large number of experiments have been performed to quantify the forced convective and nucleate flow boiling heat transfer coefficient of Al₂O₃ water based nanofluid. The employed test loop provides conditions to investigate the influence of operating parameters such as heat flux, flow mass flux and volumetric concentration of nanofluids (0.5, 1 and 1.5%). Results demonstrate that two heat transfer regions are observed namely forced convective and nucleate boiling region. Investigating on the operating parameters illustrated that with increasing the heat flux and flow rate of nanofluid, heat transfer coefficient of nanofluid dramatically increases. In contrast, with increasing the volumetric concentration of nanofluid, controversial condition is observed such that increases the heat transfer coefficient in forced convective region is reported while reduction of heat transfer coefficient is seen for nucleate boiling zone. Obtained results were then compared to Chen and also Gungor-Winterton well-known correlations. Results of this comparison show that experimental data are in a good agreement with those of obtained by correlations.