Capillary filling with wall corrugations] Capillary filling in microchannels with wall corrugations: A comparative study of the Concus-Finn criterion by continuum, kinetic and atomistic approaches

Abstract

We study the impact of wall corrugations in microchannels on the process of capillary filling by means of three broadly used methods - Computational Fluid Dynamics (CFD), Lattice-Boltzmann Equations (LBE) and Molecular Dynamics (MD). The numerical results of these approaches are compared and tested against the Concus-Finn (CF) criterion, which predicts pinning of the contact line at rectangular ridges perpendicular to flow for contact angles theta > 45. While for theta = 30, theta = 40 (no flow) and theta = 60 (flow) all methods are found to produce data consistent with the CF criterion, at theta = 50 the numerical experiments provide different results. Whilst pinning of the liquid front is observed both in the LB and CFD simulations, MD simulations show that molecular fluctuations allow front propagation even above the critical value predicted by the deterministic CF criterion, thereby introducing a sensitivity to the obstacle heigth.

25 pages, 8 figures, Langmuir in press

References in corpus (7)

• Capillary Rise in Nanopores: Molecular Dynamics Evidence for the Lucas-Washburn Equation
• Capillary filling in patterned channels
• Lattice Boltzmann simulations of apparent slip in hydrophobic microchannels
• Entropic lattice Boltzmann method for microflows
• Capillary Filling of Anodized Alumina Nanopore Arrays
• Evidence of thin-film precursors formation in hydrokinetic and atomistic simulations of nano-channel capillary filling
• Front pinning in capillary filling of chemically coated channels

Cited by in corpus (8)

• Switchable Imbibition in Nanoporous Gold
• Wetting hysteresis induced by nanodefects
• Surface growth for molten silicon infiltration into carbon millimeter-sized channels: Lattice-Boltzmann simulations, experiments and models
• Capillary filling in microchannels patterned by posts
• Molecular transport and flow past hard and soft surfaces: Computer simulation of model systems
• Mesoscopic analysis of Gibbs' criterion for sessile nanodroplets on trapezoidal substrates
• Simulation of capillary infiltration into packing structures by the Lattice-Boltzmann method for the optimization of ceramic materials
• Lattice Boltzmann simulations on the role of channel structure for reactive capillary infiltration