An Investigation Into the Non-Uniformity of Density in Nanofluids

This study uses molecular dynamics simulations to investigate the affects of platinum nanoparticle lognormal size distribution and agglomeration on the local density of the surrounding xenon base fluid. Over the range of platinum nanoparticle diameters (25–150 nm), the radial distribution function showed an increase in the local fluid density. This increase in local density is shown to be caused by the formation of liquid layers that surround the nanoparticle. Liquid layer formation is found to be highly dependent on the cross-correlation between the platinum and xenon atoms. The local density is shown to increase with smaller nanoparticle diameter and aggregation reduces this change in density. Since aggregation is a dynamic phenomenon, the density becomes both spatially and temporally dependent. This space-time dependency of nanofluid density is compared to the linear mixing models normally applied to nanofluid systems.