q&more
My watch list
my.chemie.de  
Login  

News

Liquid foam: Plastic, elastic and fluid

02-Dec-2015: 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 by Benjamin Dollet and Claire Bocher from the Rennes Institute of Physics, in Brittany, France. Ultimately, bear 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.

Original publication:
Benjamin Dollet, Claire Bocher; "Flow of foam through a convergent channel"; The European Physical J. E; 2015

Facts, background information, dossiers

More about Springer-Verlag

  • News

    Is there something up with stinky inflatable pool toys?

    Inflatable toys and swimming aids, like bathing rings and arm bands, often have a distinctive smell which could indicate that they contain a range of potentially hazardous substances. Some of these compounds, which include carbonyl compounds, cyclohexanone, phenol and isophorone, might be c ... more

    Ruby red improves in the microwave oven

    Researchers from India’s CSIR - Institute of Minerals and Materials Technology (IMMT) have tested a new way to improve the colour, clarity and lustre of rubies: microwaves. Rubies are among the world’s most popular precious gemstones, and are also used in high power switches and sensors. Mo ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:

 

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE