Work

Morphological transitions of a Newtonian bubble rising in a viscoelastic liquid

Year: 2026

Type: article

Abstract: A Newtonian bubble rising in a viscoelastic liquid can either elongate and split or retain a quasi-spherical (QS) shape, but a unifying mechanistic explanation for these distinct morphologies has been lacking. We show that the key factor is the location of hoop stress relaxation relative to the bubble interface. Localization of stress relaxation near the trailing interface sustains axial stretching and capillary pinch-off, resulting in elongation and either continuous or early-stage splitting. In contrast, migration of the relaxation zone away from the bubble interface suppresses tail growth and promotes recovery toward a QS shape. Phase-field computations based on the Giesekus model across ranges of Ca, Wi, and polymeric viscosity ratio (1−β) show that the competition between viscoelastic and capillary stresses delineates four morphological regimes and establishes a predictive connection between polymer relaxation dynamics and macroscopic bubble shape in viscoelastic multiphase flows.

Source: Physics of Fluids

DOI: 10.1063/5.0332231

Authors: Woohyeon Jo, Youngdon Kwon, Jaewook Nam

Institutions: Seoul National University, Sungkyunkwan University

Language: English

Topic: Fluid Dynamics and Heat Transfer

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Funder: National Research Foundation of Korea

Awards: G1096103490, G4535178046