Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 21: Amorphous and Liquid Materials II
MM 21.4: Vortrag
Dienstag, 28. März 2006, 17:15–17:30, IFW D
The oscillation spectrum of two-phase liquid drops — •Leonie Kraus1, Karol Debinski2, Rudolf Schmitz2, and Ivan Egry1 — 1Institut für Raumsimulation, DLR Köln — 2Institut für Theoretische Physik, RWTH Aachen
The interfacial tension between two immiscible liquids is of basic and technical interest, especially concerning melts of multicomponent metallic alloys. In principle, it may be calculated from the oscillation spectrum of a two-phase droplet. For a force free, spherical droplet, two frequencies are expected which can be clearly assigned to the surface oscillations and the interface oscillations respectively. This assumption is approximately fulfilled for electromagnetically levitated droplets under microgravity conditions. A corresponding experiment was performed within a parabolic flight campaign in 2005. The alloy Cu40Ni30Ag30 was examined, which has a stable miscibility gap in the liquid range.
In levitation experiments on Earth, the gravitational force and the levitation force break the spherical symmetry of the droplet. So the external forces need to be considered and the corresponding theory should be extended. In general, for the lowest translation and oscillation modes, one gets a 16-dimensional equation of motion, which may be approximatively diagonalized.
In this talk, both the experimental results from the parabolic flight and the theory for aspherical two-phase drops are introduced and discussed.