Large-Scale Streaming Caused by Forced Vertical, Cyclic Motion of Fluid-Fluid Interface: Interface Wave Profile and Overall Flow Behavior

Large-scale streaming can occur near the interface between immiscible liquids when the liquids are excited vertically within a cylindrical enclosure. The most significant feature of this phenomenon is formation of an intermittent, but unidirectional, jet-like flow that leaves the center of the interface when an axisymmetric, fundamental-mode wave is exited on the interface. The jet induces a large-scale recirculating flow extending a few cylinder diameters away from the interface, a spatial scale considerably greater than the wavelength or amplitude of the interface waves, and having a time scale much greater than the excitation inter-val. The depth of the recirculation region increases with an increase in the wave amplitude. The recirculating flow is driven by a downward jet that forms below the center of the interface. The downward jet persists because a stagnation point forms below the interface each time when the center of interface is rising to form a crest.