论文标题
多孔介质中雷利 - 泰勒混合的缩放
Scaling of Rayleigh-Taylor mixing in porous media
论文作者
论文摘要
将两种具有不同密度的流体推向另一个流体会导致雷利 - 泰勒不稳定性在其界面上的发展，这进一步在复杂的混合层中进化。在多孔媒体中，此过程受到毛孔流动时所经历的粘性阻力的影响，这是由达西定律描述的。在这里，我们通过在三个和两个维度的直接数值模拟中调查了Darcy-Rayleigh-Taylor系统的混合特性，以大péclet数的极限。在混合区中，重力和粘性力之间的平衡导致伸长的羽流的非自动相似性生长，其长度在及时线性上增加，而其宽度则遵循扩散的生长。发现质量转移的努塞尔特数与达西·雷利（Darcy-Rayleigh）的数字有线性增加，从而支持高RA数量的多孔对流量表。最后，我们发现混合过程显示了两个和三个维度之间的重要定量差异。
Pushing two fluids with different density one against the other causes the development of the Rayleigh-Taylor instability at their interface, which further evolves in a complex mixing layer. In porous media, this process is influenced by the viscous resistance experienced while flowing through the pores, which is described by the Darcy's law. Here, we investigate the mixing properties of the Darcy-Rayleigh-Taylor system in the limit of large Péclet number by means of direct numerical simulations in three and two dimensions. In the mixing zone, the balance between gravity and viscous forces results in a non-self-similar growth of elongated plumes, whose length increases linearly in time while their width follows a diffusive growth. The mass-transfer Nusselt number is found to increase linearly with the Darcy-Rayleigh number supporting a universal scaling in porous convection at high Ra numbers. Finally, we find that the mixing process displays important quantitative differences between two and three dimensions.
