Compression-driven viscous fingering in a radial Hele-Shaw cell

Abstract

The viscous-fingering instability that emerges when gas is injected into a liquid-filled Hele-Shaw cell is a paradigm of pattern formation that has been extensively studied. Here, we examine a previously neglected aspect of the problem: The compressibility of the injected gas. We use experiments, numerical simulations, and an axisymmetric model to show that gas compression controls the time-dependent injection rate and systematically delays the onset of viscous fingering at high capillary number. We quantify the importance of gas compression with a single dimensionless compressibility number.

Topics & Concepts