Anomalous Wave Dispersion in the Cyclohexanedione-Bromate Chemical Oscillator

A modified six-variable Oregonator model presented here successfully reproduces a significant portion of the behavior observed in the Ferroin-catalyzed cyclohexanedione variant of the Belousov-Zhabotinsky (CHD-BZ) reaction. The phenomena of anomalous velocity dispersion (in which following waves may catch up to, rather than fall behind an initial excitation wave), wave-stacking, and backfiring have been successfully reproduced numerically as resulting from non-monotonic [Br<super>-</super>] decay to the steady state in the wake of an excitation pulse. The non-monotonic decay is seen as a "dip" in [Br<super>-</super>] following the passage of a chemical wave. This dip in [Br<super>-</super>] decay curve allows a following wave to accelerate and catch up to the initial wave. The origin of anomalous dispersion as the result of such a non-monotonic decay curve in [Br<super>-</super>] has been suggested previously by Steinbock et al. and Szalai et al. However, the work presented here is the first successful representation of anomalous wave-velocity dispersion using a chemical model. This model is based on the well-understood chemistry of the Oregonator model of the Belousov-Zhabotinsky reaction, coupled to a second pathway (based on chemistry related to uncatalyzed bromate oscillators) for the oxidation of organic substrate to provide the new dynamics.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Grantor dc:publisher

University of Montana

Year

2012

Author dc:creator

• Boger, Ryan

• anomalous dispersion
• BZ reaction
• chemical kinetics

Repository record dc:identifier

https://scholarworks.umt.edu/etd/146

OAI identifier oai:identifier

oai:scholarworks.umt.edu:etd-1165