Diffusion-induced chaos in a cool flame experiment

We report on the experimental observation of diffusion-induced chaos in the cool flame domain of n-heptane oxidation under non homogeneous conditions. Two qualitatively different kinds of behaviours, the cool flame propagation and the cool flame spatial stabilization, are observed. In each case, we show that the spatiotemporal cool flame behaviour may be described in terms of dynamical system theory. In particular, we observe, in the propagation domain, a succession of Hopf bifurcations leading to a quasi periodic regime and chaos. We prove, in the stabilization domain, that the complex temporal behaviour of the cool flame may be identified with low-dimensional deterministic chaos and perform a multifractal analysis of its invariant measure.