Local and directional characteristics of nanofluids: a non-equilibrium molecular dynamics study.

Heat transfer enhancement by suspending nano-sized particles in a liquid, called nanofluid, has attracted considerable attention over the past few decades. The underlying mechanisms are an area of active research. The present study focused on the inhomogeneous and non-isotropic aspects of the thermophysical properties of nanofluids. A non-equilibrium molecular dynamics simulation was conducted, such that the temperature gradient was applied directly to the simulation domain where various particles were located, and local and directional characteristics of the heat transfer were investigated. The ordered structure in the liquid region next to the liquid-solid atomic interface played a critical negative role in altering the thermal properties that could not be predicted through the simple composite model of Maxwell. The formed liquid structure was sensitive to the surroundings, and the size, shape, and multi-particle arrangement affected the performance accordingly. Two nano-particles oscillating in the temperature-gradient direction were significantly effective in enhancing heat transfer. [ABSTRACT FROM AUTHOR]