Reduction waves in the two-variable Oregonator model for the BZ reaction

Numerical simulations of the two-variable Oregonator in a one-dimensional reaction–diffusion model are undertaken to show the formation of single reduction pulses. These are seen to exist over relatively narrow ranges of the (dimensionless) kinetic parameters ϵϵ and ff arising in the derivation of the Oregonator model, though they are seen for all values of the diffusion coefficient ratio DD considered. For the smaller values of DD a direct transition from single reduction pulses to wave trains is found. For equal diffusion coefficients, D=1.0D=1.0, this transition involves a sequence of complex spatio-temporal dynamics, including localized oscillatory behaviour and the successive spreading of a region in the reduced state. The present results are compared with results from the three-variable Oregonator and the Rovinsky–Zhabotinsky models for the BZ reaction, as well as with previous experimental observations.

► Numerical simulations of single reduction pulses in the two-variable Oregonator model for the BZ reaction. ► A complex transition from single pulses to regular wave trains. ► Solutions for different values of the ratio of diffusion coefficients of the two active species. ► Comparison with the three-variable Oregonator scheme.