ABSTRACT
Nanofluids are a two-phase system which includethe base liquidand nanoparticles, where nanoparticles with unusual properties have the non-standard properties of nanofluids. Compared with the conventional fluids, they have a large enhancement in their thermal conductivity by several percent or even tens of percentage points. Such extraordinary thermal conductivity of nanofluids attracts an increasing trend in the relevant research. As a result, measurements for the thermal conductivity of nanofluids have been investigated. Surprisingly, the fascinating results obtained by the different researchers are controversialand inconsistent, which hinder both the full understanding of the fundamental theories and the extensive applications of nanofluids. Therefore, the measurement techniques for the thermal conductivity of nanofluids are reviewed. Meanwhile, the effect of the factors such as particle concentration and particle size on thermal conductivity, is also discussed. Moreover, the potential methods for enhancing reliability of the thermal conductivity of nanofluids are proposed.
