Regensburg 2007 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 18: Brownian motion and transport II
DY 18.4: Vortrag
Dienstag, 27. März 2007, 17:30–17:45, H3
Hydrodynamic properties of fractal aggregates — •Rainer Bedrich and Roland Ketzmerick — Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany
For aggregates with a fractal-like structure, e.g. pyrogenic silica, it is important to relate their translational and rotational diffusion coefficients to their geometrical properties. We present a new algorithm, that allows for generating aggregates with any desired fractal dimension between df=1 (chains) and df=3 (spheres). Hydrodynamic properties are determined by a multipole expansion of the flow velocity at low Reynolds number [1]. We introduce hydrodynamic dimensions in analogy to the fractal dimension and obtain a universal relation between these dimensions for fractal aggregates. Aggregates from standard algorithms, like DLA, are in agreement with this relation.
[1] A. V. Filippov, J. Colloid Interface Sci. 229, 184 (2000)