Curvature‐Induced Diffusive Instability of an Autocatalytic Reaction–Diffusion Front

ABSTRACT Autocatalytic reaction–diffusion fronts are known to exhibit cellular patterns when the reactant of an autocatalytic reaction diffuses sufficiently faster than the autocatalyst . In this study, we analyze the effect of curvature on these patterns through a combined numerical and experimental approach. Experiments using the chlorite–tetrathionate reaction show earlier onset and cellular patterns of larger amplitude on radially propagating fronts than on rectilinear ones, when the autocatalyst invades the reactant . Numerical results corroborate these findings, indicating that the curvature affects the transport of the chemical species and enhances the diffusive instability of an autocatalytic front. As a consequence, there exists a range of diffusion coefficient ratios in which fronts are unstable in the radial geometry but remain stable in the rectilinear configuration. Our results underline the importance of curvature in the dynamics of autocatalytic reaction–diffusion systems.