Forced Imbibition - a Tool for Determining Laplace Pressure, Drag Force and Slip Length in Capillary Filling Experiments

TL;DR

This paper demonstrates that forced imbibition experiments, combined with computer modeling, can accurately determine key nanoscale fluid parameters like Laplace pressure, slip length, and permeability, enhancing understanding of capillary flow.

Contribution

It introduces a method to quantify multiple physical parameters in capillary filling by analyzing forced imbibition through computer simulations, providing a comprehensive and consistent approach.

Findings

Quantifies Laplace pressure, permeability, and slip length from forced imbibition.

Validates the consistency of parameter determination independently.

Shows applicability to nanoscale capillary flow analysis.

Abstract

When a very thin capillary is inserted into a liquid, the liquid is sucked into it: this imbibition process is controlled by a balance of capillary and drag forces, which are hard to quantify experimentally, in particularly considering flow on the nanoscale. By computer experiments using a generic coarse-grained model, it is shown that an analysis of imbibition forced by a controllable external pressure quantifies relevant physical parameter such as the Laplace pressure, Darcy's permeability, effective pore radius, effective viscosity, dynamic contact angle and slip length of the fluid flowing into the pore. In determining all these parameters independently, the consistency of our analysis of such forced imbibition processes is demonstrated.