Morphological stability of the interface between two fluids with similar-in-value viscosities during displacement in a Hele–Shaw cell

Abstract

The silicon oil displacement by a water solution of glycerin in a radial Hele–Shaw cell is experimentally investigated. The morphological stability of the interface between the two fluids in the course of displacement at a constant flow rate is studied. For low perturbing modes the known theoretical result concerning the existence of three domains in the displacement process, namely, stable, metastable (the interface either loses or conserves its shape), and unstable, is experimentally confirmed. For the fourth-mode perturbations the difference with the calculations is revealed: the interface behavior is always metastable.