Analysis of the modified complete oregonator accounting for oxygen sensitivity and photosensitivity of Belousov-Zhabotinsky systems

Abstract

The Oregonator model of the Belousov-Zhabotinsky (BZ) reaction is modified by introduction of a bromide flow corresponding to the influences of oxygen and/or light on BZ systems. Due to the flow term, the Oregonator may exhibit three stationary solutions with corresponding bistability. Hopf bifurcations with emanating periodic solutions occur on two independent stationary solution branches. Bifurcations appear to be subcritical if oscillations are of relaxational type due to different time scales for each variable. With decreasing differences in these time scales, supercritical Hopf bifurcations occur emanating periodic solutions with small amplitudes which are sensitive to macroscopic excitations. Transition to relaxation oscillations with large amplitudes proceeds through a folded area involving unstable limit cycles. © 1990 American Chemical Society.