Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 18: SYMPOSIUM Driven Soft Matter III

CPP 18.4: Vortrag

Dienstag, 26. Februar 2008, 17:30–17:45, C 130

Hydrodynamical jet oscillations and band structures in the flow of nano-rods — •Sebastian Heidenreich, Siegfried Hess, and Sabine H. L. Klapp — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergst. 36, D-10623

The flow properties of nano-rods are strongly affected by the dynamical behavior of molecular alignment. A theoretical description can be made by an relaxation equation [1] of the order parameter tensor. For plane Couette flow geometry the model implies a rather complex orientational behavior [2] even in the case where the alignment is spatially homogeneous and the flow profile is linear. In the last years the dynamics of the inhomogeneous alignment and the effect on the velocity profile was investigated intensively [3]. In our contribution we model fluid-wall interactions by boundary conditions for the alignment tensor (strong anchoring). Our numerical analysis for the plane Couette flow yields oscillating local spurts of the velocity profile, referred to as hydrodynamical jets which are caused by the competition of elasticity and flow coupling. Moreover, we observe time-dependent shear bands in startup flows.
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B. Chakrabarti, M. Das, C. Dasgupta, S. Ramaswamy, and A. K. Sood, Phys. Rev. Lett. 92, 055501 (2004); S. Heidenreich, P. Ilg and S. Hess, Phys. Rev. E 75, 066302 (2007)