Effect of radial advection on autocatalytic reaction–diffusion fronts

Abstract

The reaction–diffusion–advection properties of autocatalytic fronts are studied both theoretically and experimentally in the case where the autocatalytic species is injected radially into the reactant at a constant flow rate. The theoretical part analyzes both polar and spherical cases. At long times or equivalently large radius from the injection point, the well-known properties of one-dimensional reaction–diffusion autocatalytic fronts are logically recovered as the influence of the advection field decreases radially. At earlier times however, the radial advection impacts the dynamics of the front. We characterize numerically the influence in this transient regime of the injection flow rate and of the ratio of initial concentration of reactant and autocatalytic product on the position of the front, the reaction rate and the amount of product generated. We confirm experimentally the theoretical predictions in polar geometries using the autocatalytic chlorite–tetrathionate reaction.