Flow cross-overs under surface fluctuations in cylindrical nano-channel

Abstract

We analyse surface-fluctuations driven fluid flow through nano-channels (tubes) to investigate the interplay between the boundary layer and the bulk flow of fluid under a pressure head. Surface fluctuations of a wide range of frequencies (up to several hundreds of Hertz) in a nano-channel keep the flow in the low Reynolds number regime. Using this advantage of low Reynolds number flow, we develop a perturbation analysis of the fluid flow that clearly distinguishes the bulk flow under a pressure head around the axis of a nanotube from its surface flow structure induced by fluctuations. This analysis is quantifying the role of surface and fluid type on such flows which can potentially find wide applications.