Surprises in viscous flows:  from charged drops to bacteria in curved channel flows
Howard Stone, Princeton University


Laminar viscous flows are well understood, as evidenced by the extensive discussion in standard textbooks.  In this talk I present some examples of laminar flows studied in my group where the results may seem surprising. In particular, I describe experiments of drops in an electric field where oppositely charged drops fail to coalesce if the electric field is strong enough. In addition, I describe experiments with solutions of bacteria in flows in curved microchannels. Thread-like structures of biofilm are formed and the origin for these structures is traced to three-dimensional laminar flow features in the neighborhood of corners.