Dresden 2014 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 21: Pattern Formation

DY 21.7: Talk

Wednesday, April 2, 2014, 16:45–17:00, HÜL 186

Mode transitions of oscillating water drops — •Frank Rietz and Stefan C. Müller — University of Magdeburg, Institute of Experimental Physics, Pattern Formation Group

Drop oscillations occur, for example, in the rain and play a role in technological processes. The process by which a pollutant is incorporated into a rain drop depends on its shape, which changes drastically during the oscillation. Such oscillations are easily observed, if water is poured on a hot plate. At sufficiently high plate temperature the drop floats on its own steam film. The thin sheet thermally insulates the liquid and the drop survives for several minutes (Leidenfrost-effect). During the evaporation process the drop oscillates in different eigenmodes that resemble star-like shapes. The modes of the star-shaped drops spontaneously change in irregular periods. For evaporating drops on a hot plate we measure the relation between mode change, drop size, and oscillation period. Experiments are performed at shrinking and constant drop volume.