Dresden 2006 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 35: Ferro Fluids / Liquid Chrystals
DY 35.2: Vortrag
Mittwoch, 29. März 2006, 14:45–15:00, SCH 251
More precise simulations of ferrofluids’ reology — •Eric Coquelle1, Patrick Ilg1,2, and Siegfried Hess1 — 1Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany — 2LPMCN, Université Lyon I, F-69662 Villeurbanne France
Ferrofluids have attracted considerable attention in the recent years, as their field-controlled physical properties has led to mumerous application, as well as in material science as in medical field [1,2]. However, acutal simulations study No-dqperfectNo-dq magnetic suspensions, and may neglect some experimental important parameters, such as the wide size dispersion of magnetite particles. Moreover, the hydrodynamic interactions (HI) between moving particles are neglected.
Present study first infestigates the influence of these HI; the difficulty arises from the need to uncorrelate the random motion of the particles. A method inspired from the polymers simulations has been employed, reducing the computational effort to O(N^2.25).For comparison, another method based on the mobility matrix is used. The results are then compared to experimental SAXS and XPCS data.
As a second step, we model real polydisperse ferrofluid, through a system containg small and large particles. It reveals a sharp modification of the state of the simulated fluid. To go further, predictions on the magnetiviscous effect of a simulation involving both bidispersity and many-body hydrodynamic interaction will be confronted to experimental results.
[1] G. BOSSIS, E. COQUELLE, Ann. Ch. Sci. Mat. 29 (2004) 43 [2] Z. WANG, C. HOLM, Phys. Rev. E. 68 (2003) 041401