Transient complex oscillations in the closed Belousov-Zhabotinsky reaction: Experimental and computational studies

We report observations of a range of unusual behavior of a closed chemical system. A number of phenomena that are defined only for open systems have been observed as transients in a closed Belousov-Zhabotinsky (BZ) reaction. These phenomena include: successive supercritical period doublings, intermittency, mixed mode and quasiperiodic oscillations, as well as combinations of these modes. We show that even quite complex, nonchaotic oscillations are virtually independent of the stirring rate. The various types of complex behavior are exhibited by experiments that can be carried out with very simple equipment. They are therefore suitable for demonstrating complex behavior in a chemical system. We investigate the range of initial conditions that leads to complex oscillations, and present a model of the closed BZ system that exhibits some of the transient complex behavior observed.