Nonequilibrium dynamics of a stochastic model of anomalous heat transport: numerical analysis
Nonequilibrium dynamics of a stochastic model of anomalous heat transport: numerical analysis
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反常热传输随机模型的非平衡动力学：数值分析
DOI：
10.1088/1751-8113/43/14/145001
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
A. Politi
中科院分区：
文献类型：
--
作者：
L. Delfini;S. Lepri;R. Livi;C. Mejía;A. Politi
本文研究了最近邻谐振子间随机弹性碰撞的热输运问题。的协方差矩阵的运动方程数值求解自由和固定的边界条件。在热力学极限下，温度分布的形状和稳态热通量的值取决于边界条件的选择。对于自由边界条件，它们还取决于与热浴的耦合强度。此外，我们发现一个强烈的违反局部平衡的链边缘，确定两个边界层的大小（其中N是链长），其特征在于从散装不同的标度行为。最后，我们调查的放松对稳定状态，发现两个长的时间尺度：第一个对应于放松的流体动力学模式;第二个是有限的系统的表现。
We study heat transport in a chain of harmonic oscillators with random elastic collisions between nearest-neighbours. The equations of motion of the covariance matrix are numerically solved for free and fixed boundary conditions. In the thermodynamic limit, the shape of the temperature profile and the value of the stationary heat flux depend on the choice of boundary conditions. For free boundary conditions, they also depend on the coupling strength with the heat baths. Moreover, we find a strong violation of local equilibrium at the chain edges that determine two boundary layers of size (where N is the chain length) that are characterized by a different scaling behaviour from the bulk. Finally, we investigate the relaxation towards the stationary state, finding two long time scales: the first corresponds to the relaxation of the hydrodynamic modes; the second is a manifestation of the finiteness of the system.