Selection of flow-distributed oscillation and Turing patterns by boundary forcing in a linearly growing, oscillating medium.
Selection of flow-distributed oscillation and Turing patterns by boundary forcing in a linearly growing, oscillating medium.
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在线性增长的振荡介质中通过边界强制选择流动分布振荡和图灵模式。
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发表时间：
2009
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通讯作者：
M. Menzinger
中科院分区：
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作者：
D. G. Míguez;P. McGraw;A. Muñuzuri;M. Menzinger
我们研究了振荡化学二氧化氯-碘化物-丙二酸 (CDIMA) 介质的线性生长域对其生长边界处的周期性强迫的响应。介质是霍普夫不稳定的，也是图灵不稳定的，系统对流不稳定。结果证实了数值预测，即可以通过控制边界处的驱动频率来激发两种不同的图案模式：在低强迫频率 f 值下的流动波分布振荡（FDO）模式，以及在高 f 值下的稳态图灵图案模式。将实验图案的波长和相速度与动态模拟的结果以及线性色散关系的预测进行定量比较。 FDO 波的结果与这些预测非常吻合，并且遵循由边界驱动频率选择的频率的相波的预期运动学关系。图灵模式也在预测的强迫频率范围内生成，但这些发展成二维结构，一维数值和分析模型无法完全解释。当去除强迫时，由边界强迫激发的图灵模式仍然存在，证明了非受迫、恒定尺寸介质的双稳态。在实验以外的扰动频率下的动力学模拟表明，在一定的强迫频率范围内，FDO波变得不稳定，分解成不同频率、波长和相速度的谐波。
We studied the response of a linearly growing domain of the oscillatory chemical chlorine dioxide-iodide-malonic acid (CDIMA) medium to periodic forcing at its growth boundary. The medium is Hopf-, as well as Turing-unstable and the system is convectively unstable. The results confirm numerical predictions that two distinct modes of pattern can be excited by controlling the driving frequency at the boundary, a flow-distributed-oscillation (FDO) mode of traveling waves at low values of the forcing frequency f , and a mode of stationary Turing patterns at high values of f . The wavelengths and phase velocities of the experimental patterns were compared quantitatively with results from dynamical simulations and with predictions from linear dispersion relations. The results for the FDO waves agreed well with these predictions, and obeyed the kinematic relations expected for phase waves with frequencies selected by the boundary driving frequency. Turing patterns were also generated within the predicted range of forcing frequencies, but these developed into two-dimensional structures which are not fully accounted for by the one-dimensional numerical and analytical models. The Turing patterns excited by boundary forcing persist when the forcing is removed, demonstrating the bistability of the unforced, constant size medium. Dynamical simulations at perturbation frequencies other than those of the experiments showed that in certain ranges of forcing frequency, FDO waves become unstable, breaking up into harmonic waves of different frequency and wavelength and phase velocity.