Drop dynamics of viscoelastic filaments

Hrishikesh Pingulkar (1) , Jorge Peixinho (2) , Olivier Crumeyrolle (1)

1 LOMC - Laboratoire Ondes et Milieux Complexes
2 PIMM - Laboratoire Procédés et Ingénierie en Mécanique et Matériaux

The stretching of viscoelastic polymer solutions close to breakup can create attached drops on a filament, whose properties and dynamics are little understood. The stretching of capillary bridges and the consecutive filament, until its breakup, can be quantified using diameter-space-time diagrams, which demonstrate hierarchy, as well as asymmetry of satellite drops around a big central drop. All drops experience migration, oscillation, and merging. In addition, the position of the minimum diameter on the filament is determined, along with the number of drops, their positions, the diameters of drops and the filament breakup time. The maximum number of drops on the filament can be predicted using the Deborah number. The diagrams also quantify the large Hencky strains in the filaments before pinch-off. The obtained minimum diameter is used to measure the extensional viscosity, which indicates the effect of polymer concentration and direction of filament thinning.

Mots clés: Viscoelasticity; Capillary bridges; Deborah numbers; Extensional viscosity; Minimum diameters; Polymer concentrations; Satellite drops; Space-time diagrams; Viscoelastic polyme; Drops

Domaines: Matériaux

Hrishikesh Pingulkar, Jorge Peixinho, Olivier Crumeyrolle. Drop dynamics of viscoelastic filaments. Physical Review Fluids, 2020, 5 (1), pp.1-8. ⟨10.1103/PhysRevFluids.5.011301⟩. ⟨hal-02533880⟩