Multiscale drainage dynamics with Haines jumps monitored by stroboscopic 4D X-ray microscopy

Area of Science:

• Physics
• Fluid Dynamics
• Materials Science

Background:

• Multiphase flow in porous media exhibits deterministic dynamics governed by spatiotemporal processes.
• Existing 3D microscopy methods lack the millisecond resolution needed to study pore-scale fluid dynamics, particularly Haines jumps.

Purpose of the Study:

• To develop and apply a novel four-dimensional (4D) imaging technique for observing fast, pore-scale multiphase flow dynamics.
• To achieve unprecedented spatiotemporal resolution for capturing events like Haines jumps in situ.

Main Methods:

• Utilized stroboscopic X-ray micro-tomography to capture 4D (3D + time) data of multiphase flow in a consolidated porous medium.
• Exploited the repeatability of Haines jumps during imbibition-drainage cycles to reconstruct high-resolution 3D movies.
• Achieved a 2 kHz frame rate over a 6.5 s duration for detailed fluid dynamics observation.

Main Results:

• Successfully visualized multiscale liquid dynamics with two orders of magnitude higher spatiotemporal resolution than previously possible.
• Reconstructed pore-scale events, including Haines jumps, revealing detailed interfacial dynamics, fluid-front displacements, and velocities during drainage.
• Demonstrated the deterministic and repeatable nature of Haines jumps as a key to high-resolution imaging.

Conclusions:

• The developed 4D X-ray micro-tomography method provides unprecedented insight into fast pore-scale processes in porous media.
• This technique enables the study of deterministic mesoscopic phenomena beyond fluid flow, opening new avenues for scientific investigation.