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

Belousov-Zhabotinsky(BZ)反应是非平衡开放条件下体系的一个典型例子。通过用反应扩散机制对模式动力学进行建模，了解了系统中观察到的螺旋结构和目标模式等自组织现象。我们发现了在激发化学波的溶液层中诱导的对流。它们是与螺旋波相关的振荡流，与加速化学波(Bim波)相关的发展对流。在这项研究中，我们用实验和理论相结合的方法来理解化学波列中出现的流动波等奇怪现象。指出不仅与相应化学波列有关的Marangoni不稳定性，而且反应物和/或催化剂的全球分布对表面张力驱动的对流是有效的。新的发现是：1)在化学螺旋波的激励下，在大直径(大于15 cm)的反应器中观察到流出波；2)流波的形状由目标变为螺旋形。螺旋流波(波长60 mm，旋转周期40s，传播速度1500μm/S)在化学螺旋波(波长1.0 mm，旋转周期20s，传播速度100μm/S)模式下旋转。3)考虑催化剂和反应物的分布梯度进行了数值实验。我们观察到了化学波中的周期性不稳定性和对流结构中的周期性变化这两种奇怪的动力学。上述结果已在一次国际会议上发表，该会议的主题是“从细胞到大脑的复杂系统的动力学方面(2000.11：日本仙台)”。特别是，将在德国举行的关于马兰戈尼对流的国际会议(吉森：2001.9)上将提出对新发现的机械解释。

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).