FLOW WAVES INDUCED BY CHEMICAL WAVE TRAINS TRAINS AND DYNAMIC BEHAVIOR OF SURFACE DEFORMATION WAVES

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Belousov-Zhabotinsky (BZ) reaction is known as a typical example of the system under non-equilibrium and open conditions. Self-organizations such as spiral structures and target patterns observed in the system have been understood by modeling the pattern dynamics with reaction-diffusion mechanism. We have found convection flows induced in the solution layer exciting chemical waves. They are oscillatory flow associated with the spiral waves and developed convection associated with the accelerating chemical waves (bim waves). In this study, we carried out both experimental and theoretical approaches to understand the curious phenomena such as flow waves appeared in the chemical wave trains. It was pointed out that not only the Marangoni instability associated with the respective chemical wave trains but also a global distribution of reactants and/or catalysts are effective to bring the surface tension driven convection. New findings are1) Outgoing flow waves are observed in a reactor having a large diameter (more than 15 cm) under the excitation of chemical spiral waves,2) The flow waves change their pattern shape from target to spiral. The spiral flow waves (having wavelength 60mm, rotation period 40s, and propagation velocity 1500μm/s) are rotating in the underlying pattern of chemical spiral waves (having wavelenth 1.0mm, rotation period 20s, and propagation velocity 100μm/s).3) Taking the distribution gradients of catalysts and reactants into account numerical experiments are carried out. We observed two curious dynamics of periodic instability in the chemical waves and periodic change in the convection structure.The above results have been reported at an international conference on "Dynamic Aspects of Complex Systems from Cell to Brain (2000.11 : Sendai, Japan)". Especially, a mechanistic explanation of the new findings will be presented in the international conference on Marangoni convection to be held in Germany (Giessen : 2001.9).