Bubble Entrapment Condition in Bingham Materials

Lucas H.P. Deoclecio (1) , Edson J. Soares (1) , Hiranya Deka (2) , Jean-Lou Pierson (2)

1 UFES - Universidade Federal do Espirito Santo
2 IFPEN - IFP Energies nouvelles

We investigate the entrapment condition of initially spherical and ellipsoidal Newtonian bubbles in viscoplastic materials using direct numerical simulations. For a spherical bubble, the entrapment condition depends on the balance between the buoyancy force and the force exerted by the yield stress of the viscoplastic material. For non-spherical bubbles, surface tension may yield the surrounding material to minimize the surface energy of the bubble. The yielding of the surrounding material by surface tension force facilitates the rising motion of bubbles. Although surface tension may yield the surrounding material and start the rising motion, the bubble may get entrapped later if the stress exerted by buoyancy force is less than the yield stress of the material. We evaluate the yield-stress parameter for different bubble shapes over a range of non-dimensional parameters to predict the critical yield-stress parameter for the entrapment of a bubble.

Mots clés: Viscoplastic liquids; Bubble entrapment; Yield-stress parameter

Domaines: Matériaux

Lucas H.P. Deoclecio, Edson J. Soares, Hiranya Deka, Jean-Lou Pierson. Bubble Entrapment Condition in Bingham Materials. Journal of Non-Newtonian Fluid Mechanics, 2021, 295, pp.104616. ⟨10.1016/j.jnnfm.2021.104616⟩. ⟨hal-03433192⟩