Capillary filling dynamics of water in nanopores
Click to view
Slip lengths (normalized with respect to channel height) obtained from independent NEMD simulations in filled-up channels of varying wettability, corresponding to different values of a dimensionless acceleration parameter, . Bold lines represent the closet fits considering -based functional dependence. Inset (right) shows the variation of slip length with inverse of the acceleration (m/s2) values typically encountered in a capillary filling environment over the spatio-temporal regime considered. Inset (left) shows the normalized l s plotted against non-dimensional acceleration . Irrespective of the details of the underling roughness-wettability-driving force coupling, the dimensionless slip lengths converge to a single universal curve (see inset (left); in which scattered points represent NEMD data). S in the legend represents smooth wall.
Click to view
MD results (identified by markers, corresponding to various contact angles) depicting the meniscus dynamics in a capillary being continuously filled as a function of time, with the roughness parameter N = 4 (as an illustrative example). The dashed straight line depicts the LW dynamics without slip for completely wetting capillary wall which matches with the capillary rise of LJ fluids. The bold lines depict the predicted behavior obtained by solving the LW model coupled with the universal DSL based closure model, approximated in the forms of linear fits. The inset, as a representative scenario, depicts the simulation data and one-dimensional predictions (with our DSL model) corresponding to nanopores with varying roughness characteristics, corresponding to θ = 45°. S in the legend represents smooth wall.
Article metrics loading...
Full text loading...