Chaotic flow in competitive exothermic–endothermic reaction systems

Abstract

We study the effects of two-dimensional chaotic advection on a chemical system characterised by competitive exothermic and endothermic reactions. In previous studies, in which advective flow and reaction processes were assumed to dominate weak diffusive effects, two distinct behaviours were observed in the system. The first, when the stirring is fast and the reaction is slow. In this case, flame quenching occurs. In contrast, when the stirring is slow and the reaction is fast, local temperature perturbations lead to a stationary flame with a complex filament structure. We show here that, when the diffusion process is more influential, as for example in many microfluidic contexts, a third type of behaviour is possible, in which an expanding swirling travelling wave develops. We explore the parameter values which separate these different behaviours.