Understanding stability, measurements, and mechanisms of Thermal conductivity of Nanofluids(Article)

In the last two decades, the development of nanofluids led to many attempts to apply efficiently the discovered enhancements in thermal conductivity caused by the presence of nanoparticles (d < 100 nm) in the common heat transfer liquids, from low to moderate temperatures. However, the needs to obtain data for several systems led the researchers to many artificial conclusions that differ from laboratory to laboratory and, sometimes, in the same laboratory. The main problems are the preparation of the nanofluids, the characterization of the nanoparticles employed, and the instrumentation used to measure thermal conductivity. In addition, the understanding of the structures of nanofluids, namely the interaction of the nanoparticles with the bulk base fluid is fundamental particularly the characteristics and size (extension in space) of interface (nanoparticle/fluid), as the most significant theories of heat transfer in nanofluids are strongly dependent on them. © 2017 by American Scientific Publishers All rights reserved.