Paradoxical flows in complex fluids

Abstract eng:
It is well known that suspended particles strongly affect fluid flows. In this talk, we briefly describe two systems in which particles produce paradoxical motions in fluids. In a first example, we show that floating particles cause a flow reversal, leading to contamination of an upstream reservoir of clean water by particles in a dirty downstream reservoir, and in a second example, we demonstrate that vertically vibrating a plate in a cornstarch suspension causes the suspension to vigorously ratchet up the plate. Both examples produce motion against the direction imposed by gravity, and both can be analyzed in terms of well understood phenomena — the first due to interfacial forces, and the second due to non-Newtonian forces.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket