COMPLEX SPATIOTEMPORAL PATTERNS IN AN OPEN-FLOW REACTOR

Reaction-diffusion systems in open-flow heterogeneous reactors are kno wn to yield different instabilities and exhibit complex spatiotemporal dynamics. A particular mechanism leading to such behaviors is suggest ed here. Differential convection and differential diffusion can simult aneously induce instabilities at separate bands of wave numbers in an extended system where an activator-inhibitor reaction is taking place. The nonlinear interaction of these modes is shown to generate complex patterns with two different characteristic wavelengths and irregular temporal behavior in a distributed reactor for conditions at which a w ell-mixed reactor would exhibit no instability. The regions in the par ameter space for two model kinetics where such patterns should exist a re predicted a priori by normal form analysis of the relevant amplitud e equations and validated with numerical simulations of the full parti al differential equations. This mechanism for complex spatiotemporal b ehavior in open-flow reactors is expected to exist for many chemical r eactions, including nonisothermal ones.