Foams in a rotating drum
  A nearly two-dimensionnal foam is generated inside a Hele-Shaw cell half-filled with a surfactant solution. The cell is then placed vertically on a tumbler so that it rotates around its center with the cell angular velocity as the control parameter. During the foam rotation the liquid fraction increases and the foam/liquid interface deforms. The shear velocity profiles generated inside the foam are studied along two representative lines. The foam rheological properties are obtained using statistical tools and allow us to determine the foam effective viscosity. A semiempirical model is proposed for these velocity profiles, emphasizing the significance of the viscous dissipations between the bubbles and with the cell walls. 
A. Bronfort and H. Caps
cond-mat.soft physics.flu-dyn