Bursting Bubble in a Viscoplastic Medium

TL;DR

This study numerically investigates how viscoplasticity influences bubble bursting in yield stress fluids, revealing unique surface behaviors and regime-dependent dynamics distinct from Newtonian liquids.

Contribution

It introduces a detailed numerical analysis of bubble bursting in viscoplastic media, highlighting the role of yield stress in surface and flow dynamics.

Findings

Surface converges to a non-flat equilibrium shape.

Four main regimes with distinct behaviors identified.

Flow energy budgets analyzed in different regimes.

Abstract

When a rising bubble in a Newtonian liquid reaches the liquid-air interface, it can burst, leading to the formation of capillary waves and a jet on the surface. Here, we numerically study this phenomenon in a yield stress fluid. We show how viscoplasticity controls the fate of these capillary waves and their interaction at the bottom of the cavity. Unlike Newtonian liquids, the free surface converges to a non-flat final equilibrium shape once the driving stresses inside the pool fall below the yield stress. Details of the dynamics, including the flow's energy budgets, are discussed. The work culminates in a regime map with four main regimes with different characteristic behaviours.