# Dynamical coupling between connected foam films by interface transfer across the menisci

## TL;DR

This study experimentally investigates the interface transfer between connected foam films across menisci, revealing its impact on film thickness variation and providing key boundary conditions for modeling foam flow.

## Contribution

It presents the first experimental measurement of interface transfer velocity between foam films, highlighting its significance in foam flow dynamics.

## Key findings

- Measured interface transfer velocity between foam films.
- Identified significant film thickness variations due to interface transfer.
- Implications for modeling foam viscosity and flow behavior.

## Abstract

The highly confined flow of the liquid phase, trapped between the gas bubbles, is at the origin of the large effective viscosity of the liquid foams. Despite the industrial relevance of this complex fluid, the foam viscosity remains difficult to predict, because of the lack of flow characterization at the bubble scale. Using an original deformable frame, we provide the first experimental evidence of the interface transfer between a compressed film (resp. a stretched film) and its first neighbour, across their common meniscus. We measure this transfer velocity, which is a key boundary condition for local flows in foams. We also show the dramatic film thickness variation induced by this interface transfer, which may play an important role in the film thickness distribution of a 3D foam sample.