Phase Field Approach to Multiphase Flow Modeling
Phase Field Approach to Multiphase Flow Modeling
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DOI：
10.1007/s00032-011-0171-6
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发表时间：
2011-12-01
影响因子：
1.7
通讯作者：
Mauri, Roberto
中科院分区：
文献类型：
--
作者：
Lamorgese, Andrea G.;Molin, Dafne;Mauri, Roberto
我们回顾相场（也称为扩散界面）模型的流体流动，其中所有的数量，如密度和成分，被假定为在空间中连续变化。这种方法是货车德瓦耳斯的理论的自然延伸的临界现象的单组分，两相流体和部分互溶的液体混合物。推导出运动方程，假设一个简单的表达式为成对相互作用势。特别是，我们看到一个非平衡，可逆体力出现在Navier-Stokes方程，这是成比例的广义化学势的梯度。这种力，即所谓的Korteweg力，是造成在相变期间在其他静止系统中观察到的对流的原因。此外，在二元混合物中，扩散通量建模使用Cahn-Hilliard本构关系与组成相关的扩散率，表明它减少到菲克定律在稀释极限的情况下。最后，几个数值模拟的结果进行了描述，建模，特别是，a）混合，B）spinodal分解，c）成核，d）增强传热，e）液-汽相分离。
We review the phase field (otherwise called diffuse interface) model for fluid flows, where all quantities, such as density and composition, are assumed to vary continuously in space. This approach is the natural extension of van der Waals' theory of critical phenomena both for one-component, two-phase fluids and for partially miscible liquid mixtures. The equations of motion are derived, assuming a simple expression for the pairwise interaction potential. In particular, we see that a non-equilibrium, reversible body force appears in the Navier-Stokes equation, that is proportional to the gradient of the generalized chemical potential. This, so called Korteweg, force is responsible for the convection that is observed in otherwise quiescent systems during phase change. In addition, in binary mixtures, the diffusive flux is modeled using a Cahn-Hilliard constitutive law with a composition-dependent diffusivity, showing that it reduces to Fick's law in the dilute limit case. Finally, the results of several numerical simulations are described, modeling, in particular, a) mixing, b) spinodal decomposition, c) nucleation, d) enhanced heat transport, e) liquid-vapor phase separation.