DYNAMICS OF THE OSCILLATION PHASE DISTRIBUTION IN THE BZ REACTION

Oscillation phase dynamics in the homogeneous autooscillating Belousov -Zhabotinsky (BZ) reaction have been studied by computer simulations. The wave dynamics in autooscillating media are qualitatively different from those in excitable media for sufficiently long waves. We propose a classification of chemical waves which is based on the analysis of the shape of the dispersion curve. This delimits conventionally the wa ves with properties analogous to those in excitable media, ''trigger w aves'', from ''phase waves''. In particular, we study the phenomenon o f the ''dephasing wave'', recently observed experimentally (Aliev, R. R. J. Phys. Chem. 1994, 98, 3999). This is a special form of phase wav e dynamics, which looks like a propagating wave of phase triggering to ward a uniform value. We show that phase wave dynamics, including the dephasing waves, can be described in terms of the phase diffusion equa tion, the well-known Burgers equation. This description remains qualit atively valid for a wide range of wavelengths.