Dynamics of binary mixtures in inhomogeneous temperatures
Dynamics of binary mixtures in inhomogeneous temperatures
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DOI：
10.1088/1751-8113/41/10/105001
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发表时间：
2008-02
期刊：
影响因子：
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通讯作者：
G. Gonnella;A. Lamura;A. Piscitelli
中科院分区：
文献类型：
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作者：
G. Gonnella;A. Lamura;A. Piscitelli
给出了具有可变温度和浓度梯度的流体二元混合物对熵和内能的贡献的动力学描述。利用质量、动量和能量平衡方程，结合熵产生的标准表达式，得到了考虑温度和浓度梯度贡献的广义Gibbs-Duem关系。然后推导出压力张量的表达式。作为应用实例，在忽略速度场贡献的情况下，对界面行为和相分离进行了二维数值研究。在具有恒定温度梯度的最简单情况下，发现平均尺寸的磁畴的增长指数具有通常的值z=1/3，并且磁畴在温度梯度的方向上表现为拉长。当系统与外壁接触淬火时，显示了系统内温度分布的演变，并以垂直于热梯度的界面来表征磁畴形态。
A dynamical description for fluid binary mixtures with variable temperature and concentration gradient contributions to entropy and internal energy is given. By using mass, momentum and energy balance equations together with the standard expression for entropy production, a generalized Gibbs–Duhem relation is obtained which takes into account thermal and concentration gradient contributions. Then an expression for the pressure tensor is derived. As examples of applications, interface behavior and phase separation have been numerically studied in two dimensions neglecting the contributions of the velocity field. In the simplest case with a constant thermal gradient, the growth exponent for the averaged size of domains is found to have the usual value z = 1/3 and the domains appear elongated in the direction of the thermal gradient. When the system is quenched by contact with external walls, the evolution of temperature profiles in the system is shown and the domain morphology is characterized by interfaces perpendicular to the thermal gradient.