REFRACTION, REFLECTION, AND FREQUENCY CHANGE OF CHEMICAL WAVES PROPAGATING IN A NONUNIFORM BELOUSOV-ZHABOTINSKY REACTION MEDIUM

Propagation of chemical waves in the Belousov-Zhabotinsky reaction in a thin layer of ferroin-loaded cation-exchange resin beads is investig ated. Dispersion relations are obtained for waves propagating in layer s of resin beads. The relations in layers of resin beads are different both in the trigger wave velocity and the refractory period, when mes h size and/or percentages of cross-linkage of resin beads are differen t. A system with a sharp boundary between two layers with different wa ve velocities is made using two different resin beads exhibiting diffe rent dispersion relations. Incident waves at any angle from the high-v elocity layer are refracted at the boundary. Waves from the low-veloci ty layer also exhibit refraction when the angle of incidence is smalle r than a critical value. Refraction obeys Snell's law. Incident waves from the low-velocity layer at angles larger than the critical value a re reflected. The angle of reflection is equal to the critical angle a nd does not depend on the incident angle. When the period of incident waves from the high-velocity layer is shorter than the refractory peri od in the low-velocity layer, wave propagation across the boundary cau ses the change of frequency.