Viscous instabilities in flowing foams: A Cellular Potts Model approach

TL;DR

This paper uses the Cellular Potts Model to simulate and analyze viscous instabilities caused by a large bubble flowing in a dry foam, successfully reproducing experimental and analytical results.

Contribution

It demonstrates the effectiveness of the Cellular Potts Model in studying foam rheology and viscous instabilities in two-dimensional flowing foams.

Findings

Large bubble moves faster than mean flow above a velocity threshold

Simulations match analytical and experimental predictions

Cellular Potts Model is useful for foam rheology studies

Abstract

The Cellular Potts Model (CPM) succesfully simulates drainage and shear in foams. Here we use the CPM to investigate instabilities due to the flow of a single large bubble in a dry, monodisperse two-dimensional flowing foam. As in experiments in a Hele-Shaw cell, above a threshold velocity the large bubble moves faster than the mean flow. Our simulations reproduce analytical and experimental predictions for the velocity threshold and the relative velocity of the large bubble, demonstrating the utility of the CPM in foam rheology studies.