Proceedings

EPJ E Highlight - Liquid foam: plastic, elastic and fluid

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Snapshots of the foam at the exit of the convergent channel

What differentiates complex fluids from mere fluids? What makes them unique is that they are neither solid nor liquid. Among such complex fluids are foams. They are used as a model to understand the mechanisms underlying complex fluids flow. Now, a team of French physicists has gained new insights into predicting how complex fluids react under stretching conditions due to the interplay between elasticity, plasticity and flow. These findings were recently published in EPJ E by Benjamin Dollet and Claire Bocher from the Rennes Institute of Physics, in Brittany, France. Ultimately, potential applications include the design of new, optimised acoustic insulators based on liquid forms, or the mitigation of blast waves caused by explosions.

In this study, the authors study foam flow in a wedge-shaped channel, where the bubbles are in a monolayer and therefore easy to visualise. The choice of a wedge structure as a type of confined space is a novel one not previously examined.

Its advantage is that it is simple enough to automatically measure important features such as elongated flow and elastic deformation, as well as plastic events like swapping of neighbouring bubbles. The study was performed in the two main modes of deformation of any material, namely through sideways, or shear deformation, and through elongation. This, in turn, made it possible to compare such flows to some simple models.

As the main new results, Dollet and his colleague quantified for the first time the connection between plastic events and the foam deformation rate. They also experimentally identified a coupling between elastic stresses and the foam deformation rate.

Better understanding foam characteristics could. ultimately, help us to further investigate how liquid foams absorb mechanical energy, i.e., through experiments on acoustical propagation and shock wave propagation in liquid foams.

Flow of foam through a convergent channel. B. Dollet and C. Bocher (2015), Eur. Phys. J. E 38: 123, DOI 10.1140/epje/i2015-15123-3

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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