Structure and dynamics of nanofluids: theory and simulations to calculate viscosity

The simplified expression of the Pozhar-Gubbins (PG) rigorous, nonequilibrium statistical mechanical theory of dense, strongly inhomogeneous fluids is used to calculate the viscosity of model fluids confined in a slit pore of several molecular diameters in width in terms of the equilibrium structure factors (i.e., the number density and pair correlation functions) of these nanofluids obtained by means of the equilibrium molecular dynamic simulations. These results are compared to those obtained by means of the nonequilibrium molecular dynamic simulations of the planar Poiseuille flow of the model nanofluids, and to the results supplied by several heuristic expressions for the nanofluid viscosity. This comparison proves that the PG transport theory provides a reliable, quantitatively accurate description of the viscosity coefficients of the model nanofluids while all the heauristic approaches fail. This success of the PG prediction of the nanofluid viscosity is because the theoretical expression accounts accurately for the nanofluid structure.