Controlling bubble coalescence in metallic foams: A simple phase field-based approach

TL;DR

This paper introduces a simple, mass-conserving phase-field model to control bubble coalescence in metallic foams by tuning interface energy, validated through benchmark tests and flow simulations.

Contribution

A novel phase-field approach that allows adjustable control of bubble coalescence in metallic foam simulations by tuning interface energy.

Findings

Model effectively controls bubble coalescence rates.

Validation confirms stability and accuracy of the model.

Flow simulations demonstrate suppression of coalescence under rotational flow.

Abstract

The phase-field method is used as a basis to develop a strictly mass conserving, yet simple, model for simulation of two-phase flow. The model is aimed to be applied for the study of structure evolution in metallic foams. In this regard, the critical issue is to control the rate of bubble coalescence compared to concurrent processes such as their rearrangement due to fluid motion. In the present model, this is achieved by tuning the interface energy as a free parameter. The model is validated by a number of benchmark tests. First, stability of a two dimensional bubble is investigated by the Young-Laplace law for different values of the interface energy. Then, the coalescence of two bubbles is simulated until the system reaches equilibrium with a circular shape. To address the major capability of the present model for the formation of foam structure, the bubble coalescence is simulated for various values of interface energy in order to slow down the merging process. These simulations are repeated in the presence of a rotational flow to highlight the fact that the model allows to suppress the coalescence process compared to the motion of bubbles relative to each other.