Spatial bistability and excitability in the chlorite-tetrathionate reaction in cylindrical and conical geometries

Spatial bistability and excitability in the chlorite-tetrathionate reaction, performed in gels fed by diffusion from one boundary, have been extensively studied, both experimentally and numerically, in a flat annular striplike geometry. We first complement these numerical results. Afterwards, we extend the calculations to the cylindrical and conical geometries. In the cylinder, we compute the limits of bistability and of excitability which are important for experiments in chemomechanics but cannot be directly measured. The results of the simulations in the conical geometry agree with previous experiments on the corresponding setup. We show that the characteristics of the traveling waves which spontaneously arise in the latter geometry provide a simple and direct experimental access to these limits.