Temperature pulse dynamics on a catalytic ring

Simple and complex motions of a high-temperature pulse on a polycrystalline nickel ring were observed during the atmospheric oxidation of hydrogen in a well-mixed reactor. The complex patterns were affected by evolving spatial nonuniformities on the catalytic surface, which led the pulse to «favor» certain positions on the ring. The shape, width, and velocity of the rotating pulse varied with azimuthal position. The observed patterns included a pulse motion interspersed with antiphase behavior as well as one with aperiodic reversal of direction. A qualitative phase space scenario is proposed, based on the idea that some of the patterns may be thought of as concatenations of nearly heteroclinic motions