Investigation of hierarchical self-organization structure of spiral flow waves induced by chemical wave trains

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the present study aimed to clarify a mechanism self-organizing a structure of flow waves, which is induced by a chemical wave trains excited in a Belousov-Zhabotinsky(BZ) reaction. Spiral chmical waves, excited in a batch reactor, continue to propagate the chemical wave trains 30-40 minutes during the reaction. In the process, an oscillatory convection is induced after the wave trains propagate all over the reactor, Then a coherent and dynamic structure of convective pattern appears. The pattern is called by the flow waves having a longw wave length (several centimeters)compared to that of the chemical waves(about 1mm). Up to now, it has been reported that the flow waves emerge at a surrounding area of the container and propagate to the center of the chemical spiral waves. In this study we found1)New type of flow waves emerged at the center of the chemical waves and propagated toward the end of the container (circular flow wave and spiral flow waves : 2000).2)A variety of flow waves ca … More n be understood as a kind of bifurcation phenomena. Two control parameters of Maronic-acid and Bromo-Maronic-acid were picked up to make a bifurcation diagram(2001)3)The spiral flow waves ware accompanied by synchronously rotating surfaced deformation(2002)4)Synchronous rotation between the flow waves and flow direction change at the surface was observed(2002). A numerical analysis was carried out to clarify the mechanistic origin of the flow waves based on a model of reaction-diffusion and convection. We extended the ordinary model into a three variables reaction-diffusion model including concentration of bromo-maronic-acid as a surface-tension active product of the BZ-reaction. We confirmed that a convection roll of long wavelength (about several centimeters) was possibly excited by the chemical waves trains (having about 1mm wavelength) in a shallow layer of the BZ-solution. Unfortunately, we could not succeed to explain the oscillatory flow, however, we found a propagation of the convection roll and a directional change of the convection in the analysis. It is important to consider the influence of gravity and surface deformation to the flow waves in the numerical analysis Less