Comparison and Critical Analysis of Experimental Results and Correlations for Thermal Conductivity of Nanofluids

E.P. Bandarra Filho, G.A. Oliveira, D. Wen
Federal University of Uberlandia, BR

Keywords: nanofluids, thermal conductivity, nanoparticle, alumina


Suspensions of nanoparticles in liquids, known recently as “nanofluids,” have generated considerable interest for their potential to enhance the heat transfer in thermal systems, and reduce the possibility of erosion, sedimentation and clogging that plagued earlier solid-liquid mixtures with larger particles. It has been found that the thermal conductivity of nanofluids is notably higher than that of the base fluid. Many attempts in this field have been made to formulate appropriate effective thermal conductivity. The goal of this study is to evaluate and compare several experimental results for thermal conductivity obtained in the literature with correlations developed to predict this property in order to determine the best correlation that fit reasonably the experimental data. Beyond this comparison, this work identified trends and inconsistencies in the measurement of thermal conductivity of nanofluids. This work also examined the influence of main parameters considered in the thermal conductivity models, determining the magnitude of influence of each factor and if this parameter plays an important role in the correlation. Therefore, from this study, none of these models can describe satisfactorily the intrinsic physical phenomenon of nanofluids, showing that is necessary to refine and improve these models to predict accurately the experimental data.