Creation of spatial structure by an electric field applied to an ionic cubic autocatalator system

The effects of applying electric fields to a reactor with kinetics based on an ionic version of the cubic autocatalator are considered. Three types of boundary condition are treated, namely (constant) prescribed concentration , zero flux and periodic. A linear stability analysis is undertaken and thi s reveals that the conditions for bifurcation from the spatially uniform st ate are the same for both the prescribed concentration and zero-flux bounda ry conditions, suggesting bifurcation to steady structures, whereas, for pe riodic boundary conditions, the bifurcation is essentially different, being of the Hopf type, leading to travelling-wave structures. The various predi ctions from linear theory are confirmed through extensive numerical simulat ions of the initial-value problem and by determining solutions to the (non- linear) steady state equations. These reveal, for both prescribed concentra tion and zero-flux boundary conditions, that applying an electric field can change the basic pattern form, give rise to spatial structure where none w ould arise without the field, can give multistability and can, if sufficien tly strong, suppress spatial structure entirely. For periodic boundary cond itions, only travelling waves are found, their speed of propagation and wav elength increasing with increasing field strength, and are found to form no matter how strong the applied field.