Regensburg 2000 – scientific programme
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DY: Dynamik und Statistische Physik
DY 17: POSTER I
DY 17.20: Poster
Monday, March 27, 2000, 15:00–18:00, D
F-Shell Blob-Model: Finite Penetration and Scaling — •D. Kienle1, R. Rzehak1, and W. Zimmermann2 — 1Institut für Festkörperforschung und Forum Modellierung — 2Universität des Saarlandes, Institut für Theoretische Physik
Brownian dynamics simulation is a powerful tool to get a better microscopic understanding of polymer-flow interaction, which is important to understand phenomena such as turbulent drag reduction. Furthermore, the insight obtained from simulations is used to improve more coarse-grained polymer models like the blob-model. We present a modified blob-model, the so-called F-Shell blob-model, that takes the finite penetration of the flow into the polymer into account by a constant penetration length d. It turns out that any finite penetration destroys the scaling-properties e.g. for the end-to-end distance, which can be obtained analytically in common blob-models, which are only. Furthermore, we show how to derive analytically a scaling of the penetration depth with the number segments in the local blob, so that the assumption of a constant d can be droped. We also check the scaling properties of a chain pulled at both ends or a chain fixed at one end and pulled at the other end with a constant force. For short chains the scaling depends on the boundary conditions, i.e. whether the chain is free or fixed at only one end. The possibility of a free diffusion of the free-chain destroys the scaling-laws.