Picture of wind turbine against blue sky

Open Access research with a real impact...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs.

The Energy Systems Research Unit (ESRU) within Strathclyde's Department of Mechanical and Aerospace Engineering is producing Open Access research that can help society deploy and optimise renewable energy systems, such as wind turbine technology.

Explore wind turbine research in Strathprints

Explore all of Strathclyde's Open Access research content

Viscous froth model for a bubble staircase structure under rapid applied shear : an analysis of fast flowing foam

Green, T. E. and Grassia, P. and Lue, L. and Embley, B. (2009) Viscous froth model for a bubble staircase structure under rapid applied shear : an analysis of fast flowing foam. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 348 (1-3). pp. 49-58. ISSN 0927-7757

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

The viscous froth model is applied to the rapid shear of '2-dimensional', dry foams for bubbles confined in a monolayer and arranged in an ordered staircase configuration that forms part of a hexagonal honeycomb Structure. High system energies are attained as particular films in the staircase become highly elongated under shear. Topological transformations during which bubbles exchange neighbours can relax the staircase energy, but their onset is postponed at high shear rates. Moreover as the imposed shear rate increases, the rate at which topological transformations subsequently occur cannot keep pace with the imposed shear, and secular film stretching onsets. A critical capillary number (a dimension less measure of shear rate) separates a regime where film lengths are periodic functions of imposed strain from a regime of secular growth.