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DY: Fachverband Dynamik und Statistische Physik

DY 40: Posters II

DY 40.3: Poster

Thursday, March 17, 2011, 17:00–19:00, P3

Modelling a flexible sheet swimmer with stochastic rotation dynamics on graphic processing units — •Christian Schmeltzer and Holger Stark — TU Berlin

Artificial swimmers at low Reynolds numbers have attracted a lot of attention in recent years. Concepts for the propulsion of planar flexible structures have been demonstrated [1]. Here, we present an artificial sheetlike swimmer in a viscous environment. The sheet is modelled using vertices connected by spring potentials. To prevent it from crumbling, we applied bending potentials at each vertex site. The flow fields around the sheet are calculated with stochastic rotation dynamics (SRD). SRD is a multi-particle collision method capable of simulating mesoscale hydrodynamic effects with thermal fluctuations while being easy to implement. We first investigated the diffusion of the sheet and found it to follow Zimm dynamics. We then applied external forces normal to the sheet surface at neighboring edges but with opposite directions. The sheet starts to rotate and develops a helical shape which propels the sheet forward. The simulations with SRD are optimized for parallel computation on a graphic processing unit (GPU), which reduces the calculation time considerably. I will explain how the sheet is coupled to the SRD fluid and how the simulation speed increases due to parallel computing on the GPU.

[1] Garstecki et al. Propulsion of flexible polymer structures in a rotation magnetic field. J. Phys.: Condens Matter 21 204110 1-8 (2009).