Size effect on nanochannel flow explored by the flow factor approach model

The flow factor approach model (FFAM) was newly compared with molecular dynamics simulation (MDS) when simulating the Poiseuille flow in a nano slit pore where the effect of the solidified layer on the confining wall may be considerable. For direct comparisons, the MDS results were for no fluid-wall interfacial slippage under a relatively strong fluid-wall interaction; In this case, certain solidified layers may occur on both the confining walls. The comparisons show that these two approaches match well not only in the flow velocity profiles across the channel height but also in the volume flow rates through the channel. The study shows that when the total thickness of the solidified layers on the walls is comparable to the channel height, the effective channel height which is the nominal channel height minus the total thickness of the solidified layers on the walls, may need to be incorporated by FFAM for simulating a nanochannel flow; Otherwise, the effect of the solidified layer on the wall is negligible.