Patterns of temperature pulses on electrically heated catalytic ribbons

Abstract

A rich and intricate variety of spatiotemporal temperature patterns is predicted to exist on the surface of a thin catalytic ribbon, the average temperature of which is kept by electrical heating at a preset value, when the catalytic surface undergoes slow activation-deactivation. The control of the average temperature introduces an integral constraint that generates patters that are not observed in its absence. This one-dimensional system exhibits (in addition to a chaotic behavior) four basic motions: unidirectional pulses, back-and-forth pulses, antiphase oscillation, and a source point from which two pulses emanate and move in opposite directions. Other motions we observed are combinations and transitions among these four. Several of the motions have already been observed experimentally. At some transitions, spatial structures appear to change discontinuosly and without hysteresis, suggesting global bifurcations.