Regensburg 2000 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 42: Wachstum und Grenzfl
ächen
DY 42.6: Vortrag
Donnerstag, 30. März 2000, 12:15–12:30, H2
Dynamische Simulation von Interface Morphologien im freien dendritischen Wachstum — •Heike Emmerich1, Klaus Kassner1, and Thomas Ihle2 — 1Universität Magdeburg, CTP, PF 4120, 39016 Magdeburg — 2University of Minnesota, Minneapolis, USA
We study the evolution of interface morphologies in free dendritic growth with heat or mass transport by either diffusion alone or by both diffusion and convection. This is done by quantitative numerical simulations; in particular, we try to capture the effects of crystalline anisotropy accurately, avoiding artefacts of the numerical grid. Tracking the interface dynamically, we find oscillating structures that can be related to transient behaviour in extended systems. The set-up of our program allows us to directly compare the effects of diffusion on the evolving patterns versus those of convection. Our overall aim is to study how the morphology diagram suggested by Brener et al. [Phys. Rev. E 54, 2714 (1996)] is to be extended as a function of parameters describing convection. Here we present intensive studies of the Oseen flow approximation and give an outlook on how to carry our results over to directional solification, in particular the experiment morphin carried out during the TEXUS 36 Mission.