Dresden 2011 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 30: Reaction-Diffusion Systems

DY 30.7: Vortrag

Donnerstag, 17. März 2011, 11:45–12:00, ZEU 118

Control of spatiotemporal chaos by flow in a reaction-diffusion-advection system — •Igal Berenstein and Carsten Beta — Institute of Physics and Astronomy, University of Potsdam, Germany

We report spatiotemporal chaos in the Oregonator model of the Belousov-Zhabotinsky (BZ) reaction. Uniform oscillations and traveling waves are unstable and spatiotemporal chaos spontaneously develops in a regime, where the underlying local dynamics show stable limit cycle oscillations (diffusion-induced turbulence). We show that spatiotemporal chaos can be suppressed by a unidirectional flow in the system. With increasing flow velocity, we observe a transition scenario from spatiotemporal chaos via a regime of travelling waves to a stationary steady state. At large flow velocities we recover the known regime of flow distributed oscillations (stationary structure). We also investigated systems with a gradient in one of the parameters. We show that in such systems, localized domains of spatiotemporal chaos can be found if the gradient is sufficiently small, i.e., if the size of the chaotic domain is large compared to the diffusive length scale. Finally, we show that spatiotemporal chaos can be suppressed by allowing diffusive exchange of the activator between the reaction- diffusion system and a non-reacting layer. The type of pattern that is formed is independent of a flow in the non-reactive layer.