Interfacial wave motions due to Marangoni instability - II. Three-dimensional characteristics of surface waves in annular containers

In annular containers, traveling periodic wavetrains are generated in liqui d layers due to the surface adsorption and subsequent liquid absorption of a miscible surface-active substance, First, localized nucleation of shock-w ave-like disturbances are generated by the Marangoni effect. Then, these di sturbances yield to surface-wave trains with three-dimensional features whi ch travel through the annular container or to stationary source-and-sink st ates. To illustrate these phenomena we provide shadowgraph pictures of the waves, space-time diagrams showing the wave evolution and wave modulation, mean frequency of wavetrains as a function of the wave mode, surface deform ation, peak-to-trough wave amplitudes, wave sources and sinks, and the time evolution of the estimated Marangoni number. (C) 1999 Academic Press.