| Liquid bridges (a volume of liquid trapped between two supports) have found use in industrial processes such as zone refining, oil recovery and coating processes. Most recently, applications have focused on micro-scale and space-based microgravity processes.; This work is divided in two parts. First, an apparatus to measure rheological properties was improved and tested. The rotation of a non-Newtonian liquid bridge in a cylindrical bath filled with a viscous Newtonian fluid generates shear that deforms the interface between the two immiscible liquids. The measurement of this shape deformation is non-intrusive as it is based on image analysis. This technique allows precise measurement of very small normal stresses by comparison with surface tension forces. A polystyrene solution and a starch solution in a corresponding neutral buoyancy liquids were tested.; The second part deals with the stability of coupled liquid bridges with a view to apply it to capillary pumping. The stability of dual liquid bridge was explored for two key lengths: L = 6.5R and L = 9R. (Abstract shortened by UMI.)... |
