Three-dimensional structure of viscous fingering in miscible fluids

Abstract

The evolution of viscous fingering in a porous medium was visualized three-dimensionally. Nonlinear interaction between fingers such as tip splitting, shielding, and coalescence was observed. As the viscosity ratio increases, the finger structures become very fine. However, the tip position of the finger does not change. When the injection rate is high, the dispersion effect becomes remarkable due to the unsteady motion of the fingers, and the number density in the fingers decreases.