Article révisé par les pairs
Résumé : Viscous fingering was observed by injecting colored water into a Hele-Shaw cell preliminarily filled with a glycerin-water solution. We varied the viscosity ratio, the flow rate, the gap width, and the density ratio. The Péclet number was higher than 105. Some of the experiments were performed in microgravity conditions (parabolic flights) in order to eliminate the gravity influence on pattern formation. The video shows peculiarities of fingering in microgravity conditions for a gap width of 1.2 mm. The first sequence of two experiments shows the influence of the viscosity ratio, which was decreased by a factor of 10 from the first to the second experiment. The next sequence shows the influence of the flow velocity, which was decreased by a factor of two between the first and second experiments in this sequence.