Features of Transport processes of Nanofluids

The current state of the description of the transport processes in nanofluids is discussed. The nanofluids with spherical nanoparticles and single-walled carbon nanotubes are analyzed. It was shown that the viscosity and thermal conductivity of the nanofluids with ordinary spherical nanoparticles are not described by the classical theories. Both viscosity and thermal conductivity depend not only on particles concentration but also on their size and material. The viscosity increases with decreasing particle size, but for thermal conductivity, the opposite behavior is fixed. The rheology of the nanofluids with carbon nanotubes studied is non-Newtonian and is essentially depended on the surfactant used. The thermal conductivity of nanofluids with carbon nanotubes is significantly (at least several times) higher than the thermal conductivity of nanofluids with spherical particles. In all cases, the thermal conductivity of the nanofluids with carbon nanotubes presented is much greater than the corresponding values of the Maxwell theory.