Propagation of a reaction front in a narrow sample of energetic material with heat losses: Chaotic regimes, extinction and intermittency

The numerical simulations show that an increase in heat-losses induces, for sufficiently high Zel'dovich numbers, the Feigenbaum's cascade of period doubling bifurcations after which a chaotic dynamics is setting in. The chaotic dynamics precedes the flame extinction occurring for the further increase of the heat-loss parameter which, nevertheless, remains significantly lower than the steady extinction limit dictated by the C-shaped response curve. Apparently, the parametric dependence of the extinction time in these cases is also irregular with appreciable disparities in magnitude. Finally, the intermittency effect is detected slightly below the extinction limit with irregular dynamics alternating by apparently periodic stages. These results may be important for the flammability limits theory and practical fire safety applications.