Travelling waves in the Oregonator model for the BZ reaction

Numerical solutions of the travelling wave equations that arise in the two-variable Oregonator model for the BZ reaction are obtained for a wide range of parameter values. The main feature is the saddle-node bifurcation in the solutions, giving upper bounds for the existence of travelling waves and indicating the change from the excitable to the subexcitable regimes. The values of the upper bound f(m) of the stoichiometry factor f in the model are determined in terms of the excitability parameter epsilon for various values of the kinetic parameter q and D, the ratio of the diffusion coefficients of HBrO2 and the oxidized form of the catalyst.