Anomalous roughening of forced radial imbibition in a porous medium

TL;DR

This study investigates the anomalous roughening behavior of water front invasion in a porous medium under forced radial imbibition, revealing flow rate-dependent scaling dynamics and challenging the universality of interface growth classes.

Contribution

It demonstrates that radial imbibition exhibits flow rate-dependent roughening dynamics, differing from planar interface imbibition, thus questioning the universality of growth classes.

Findings

Growth exponents increase linearly with flow rate

Roughness exponents decrease with flow rate

Radial and planar imbibition exhibit different roughening behaviors

Abstract

We report forced radial imbibition of water in a porous medium in a Hele-Shaw cell. Washburn's law is confirmed in our experiment. Radial imbibition follows scaling dynamics and shows anomalous roughening dynamics when the front invades the porous medium. The roughening dynamics depend on the flow rate of the injected fluid. The growth exponents increase linearly with an increase in the flow rate while the roughness exponents decrease with an increase in the flow rate. Roughening dynamics of radial imbibition is markedly different from one dimensional imbibition with a planar interface window. Such difference caused by geometric change suggests that "universality class" for the interface growth is not universal.