RT Dissertation/Thesis
T1 Effects of Turbulent Flows and Superdiffusion on Reaction-Dffusion Systems
A1 Kameke, Alexandra von
K1 Reacción-difusión-advección
K1 Transporte turbulento
K1 Flujo de Faraday
AB The basic question underlying the work presented in this thesis concerns theself-organization and pattern formation in inanimate media whena fluid flow is present. This thesis studies the active and passive transport inturbulent and chaotic fluid flows. Thereby the focus is mainly of experimentalnature. Especial interest is placed on the experimental observation anddescription of new patterns emerging, when active media is subjected to a turbulentfluid flow. In particular the effect of intense mixing as can be achievedby highly chaotic or turbulent fluid flows is to be uncovered. The first goalis to characterize and explain the phenomenon of a global reactive wave in asimilar experimental realization observed by Fernandez Garca et al. in 2008.One step towards this goal is the measurement of the mixing caused bythe Faraday experiment. This experiment consists in the vertical forcing of acontainer filled with liquid. Once the velocity field had been characterized weaimed for a definition of suitable analysis methods in order to study the transportof active media on different time and length-scales. Especially for intermediaterange Damkoehler numbers, i.e. where the ratio of the timescale of the fluidflow and those of the reaction timescale is similar has not been studied in anexperimental system with an excitable chemical reaction before. The analysis tools appliedto this experimental model system might also partly be valid for the characterizationof other reaction-diffusion-advection processes as found in many naturaland men-made systems, such as plankton blooms in the ocean, chemicals in theatmosphere or bioreactors. The understanding of the role of the interplay of thetypical timescales of the reaction and advection processes are to be discovered.A simple model accounting partly for some of the observed characteristics, such as the local scale-free transport, is formulated. The interplay of diffusive and advective processes  is further studied in detail for a numerical model flow imitating the gulf-stream current.The details of this interplay can also lead to superdiffusion and scale-free transport.
YR 2013
FD 2013-03-12
LK http://hdl.handle.net/10347/7521
UL http://hdl.handle.net/10347/7521
LA eng
DS Minerva
RD 22 abr 2026