InterPore2026

Numerical Investigation of Capillary Rise Kinematics on Apparent Contact Angle

20 May 2026, 10:05

1h 30m

Poster Presentation (MS09) Pore-Scale Physics and Modeling Poster

Speaker

Prof. Christoph Arns (UNSW)

Description

Capillary forces govern fluid distribution in reservoir rocks and control multiphase transport in porous media. Quantitative evaluation of wettability, particularly in dynamically evolving systems, often relies on determining the contact angle through measurement of interfacial curvature. However, complex interface dynamics may lead to deviation of the apparent contact angle from the real value. Here, we investigate the relative magnitude of the effects of inertia, the gravity–surface tension balance, and interface oscillations on meniscus curvature during capillary rise in a vertical straight channel. In addition, we examine the effect of spatial wettability heterogeneity on capillary rise.
OpenFOAM numerical simulations based on the volume-of-fluid (VOF) method resolve the complex interface evolution and are validated against analytical solutions. Advancing and receding contact angles are set identical to eliminate the effect of material-controlled hysteresis, such as chemical heterogeneity and surface roughness, and to focus on the effect of kinematics of curvature. Nevertheless, simulations reveal pronounced hysteresis-like behaviour of the apparent contact angle as a function of interface velocity and acceleration, demonstrating the coupling between interface kinematics and curvature-based wettability estimates. Deviations of the interface geometry from a circular profile and interface oscillations are quantified as approximately an order of magnitude smaller, yet not negligible. Near-wall and axial curvatures fluctuate over timescales several times longer than the rise-to-equilibrium timescale. Furthermore, numerical simulations reveal the intricate relationship between kinematic wettability heterogeneity and capillary rise dynamics.