The Formation of a Bubble from a Submerged Orifice

TL;DR

This paper uses finite element simulations to analyze bubble formation from a submerged orifice in viscous liquids, validating scaling laws and providing detailed insights into the process across different parameters.

Contribution

It introduces a comprehensive simulation approach that captures multiscale physics and validates existing scaling laws for bubble formation regimes.

Findings

Simulation results match experimental data

Global characteristics like formation time and volume are quantified

Scaling laws are validated across parameter ranges

Abstract

The formation of a single bubble from an orifice in a solid surface, submerged in an in- compressible, viscous Newtonian liquid, is simulated. The finite element method is used to capture the multiscale physics associated with the problem and to track the evolution of the free surface explicitly. The results are compared to a recent experimental analysis and then used to obtain the global characteristics of the process, the formation time and volume of the bubble, for a range of orifice radii; Ohnesorge numbers, which combine the material parameters of the liquid; and volumetric gas flow rates. These benchmark calculations, for the parameter space of interest, are then utilised to validate a selection of scaling laws found in the literature for two regimes of bubble formation, the regimes of low and high gas flow rates.