CONFINED STATES IN LARGE-ASPECT-RATIO THERMOSOLUTAL CONVECTION
CONFINED STATES IN LARGE-ASPECT-RATIO THERMOSOLUTAL CONVECTION
复制标题
大纵横比热溶对流中的约束态
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
E. Knobloch
中科院分区：
文献类型：
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作者：
A. Spina;J. Toomre;E. Knobloch
在周期区域内对二维无滑移边界条件下的热溶质对流进行了数值模拟。该域足够大，可以跟踪完全非线性行波的相位不稳定性的演化。在研究的参数制度，这些不稳定性的发展，没有损失的相位或滞后，到一系列的局限状态或脉冲，其特征在于局部增强热和溶质运移。脉冲内行进辊的波长和相速度与背景中的波长和相速度显著不同。脉冲漂移的方向与它们所处的对流辊相同，但速度更慢，其特征在于具有指数前沿和振荡尾端。多个，显然是稳定的，状态被发现相同的参数值。脉冲的定性性质与三阶相位方程的预测吻合得很好，该方程解释了波数与相速度、振荡尾和状态的多重性之间的关系。这些属性的脉冲示出的Shil'nikov动力学在空间域中的后果。
Two-dimensional thermosolutal convection with no-slip boundary conditions is studied using numerical simulations in a periodic domain. The domain is large enough to follow the evolution of phase instabilities of fully nonlinear traveling waves. In the parameter regime studied these instabilities evolve, without loss of phase or hysteresis, into a series of confined states or pulses characterized by locally enhanced heat and solute transport. The wavelength and phase velocity of the traveling rolls within a pulse differ substantially from those in the background. The pulses drift in the same direction as the convection rolls on which they ride but more slowly, and are characterized by an exponential leading front and an oscillatory trailing end. Multiple, apparently stable, states are found for identical parameter values. The qualitative properties of the pulses are in good agreement with the predictions of a third-order phase equation which accounts for the relation between wave number and phase velocity, the oscillatory tails and the multiplicity of states. These properties of the pulses are shown to be a consequence of Shil'nikov dynamics in the spatial domain.