Bubble Formation in Yield Stress Fluids Using Flow-Focusing and T-Junction Devices

Benoit Laborie (1) , Florence Rouyer (2, 1) , Dan Angelescu (3) , Elise Lorenceau (1)

1 navier umr 8205 - Laboratoire Navier
2 Rhéophysique
3 ESYCOM - Electronique, Systèmes de communication et Microsystèmes

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.

Keywords: Yield Stress; Complex Fluids; bubble

Domains: Soft Condensed Matter [cond-mat.soft]; Strongly Correlated Electrons [cond-mat.str-el]; Atomic Physics [physics.atom-ph]

Benoit Laborie, Florence Rouyer, Dan Angelescu, Elise Lorenceau. Bubble Formation in Yield Stress Fluids Using Flow-Focusing and T-Junction Devices. Physical Review Letters, 2015, 114 (20), pp.204501. ⟨10.1103/PhysRevLett.114.204501⟩. ⟨hal-01158022⟩