title: Bubble Formation in Yield Stress Fluids Using Flow-Focusing and T-Junction Devices.
abstract: We study the production of bubbles inside yield stress fluids (YSFs) in axisymmetric T-junction and flow-focusing devices. Taking advantage of yield stress over capillary stress, we exhibit a robust break-up mechanism reminiscent of the geometrical operating regime in 2D flow-focusing devices for Newtonian fluids. We report that when the gas is pressure driven, the dynamics is unsteady due to hydrodynamic feedback and YSF deposition on the walls of the channels. However, the present study also identifies pathways for potential steady-state production of bubbly YSFs at large scale.
authors.affiliation: Université Paris-Est, Laboratoire Navier (UMR 8205 CNRS, ENPC ParisTech, IFSTTAR), 2 allée Kepler, 77420 Champs-sur-Marne, France.|Université Paris-Est, ESIEE Paris/ESYCOM, 2 Bd. Blaise Pascal, Noisy le Grand, 93162, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Laborie
authors.affiliation: Université Paris-Est, Laboratoire Navier (UMR 8205 CNRS, ENPC ParisTech, IFSTTAR), 77454 Marne-la-Vallée, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Rouyer
authors.affiliation: Université Paris-Est, ESIEE Paris/ESYCOM, 2 Bd. Blaise Pascal, Noisy le Grand, 93162, France.|Fluidion, 231 Rue St. Honoré, 75001 Paris, France.
authors.forename: Dan E
authors.initials: DE
authors.lastname: Angelescu
authors.affiliation: Université Paris-Est, Laboratoire Navier (UMR 8205 CNRS, ENPC ParisTech, IFSTTAR), 2 allée Kepler, 77420 Champs-sur-Marne, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Lorenceau