Analysis of Convective Heat Transfer Enhancement by Nanofluids: Single-Phase and Two-Phase Treatments

Abstract

Nanofluids have been investigated regarding their advantages and potentialities for the purpose of increasing convective heat transfer rates inside thermal systems where they are used as working fluids. Researchers in thermophysics have investigated these fluids experimentally and numerically. This review provides extensive theoretical information concerning nanofluids in the single-phase and two-phase treatments. Important published works on nanofluid properties and correlations are summarized and reviewed in detail. Heat transfer enhancement by nanofluids is a challenging problem due to the difficulties inherent in the model of the physical mechanism of interaction between the paricles. Here the interaction between the phases is modeled by several two-phase models, and the results are given in graphical and tabular forms. Despite the advantages of the mixture model, such as imlementation of physical properties and less computational power requirements, some studies showed that the results of the single-phase and two-phase models are very similar. The main difference consists in the effect of the drift velocities of the phases relative to each other.