Collaborative Research: 4D Visualization and Modeling of Two-Phase Flow and Deformation in Porous Media beyond the Realm of Creeping Flow

多孔介质(例如，海绵、纸张、织物、岩石和土壤)是气孔分布在固体基质中的材料。当毛孔连接在一起时，流体就可以流过它们。了解和预测流体在多孔介质中的流动非常重要，因为它发生在广泛的应用中，从地下水和土壤的污染到纸张和织物上的印刷。通过了解流动路径，我们可以对流体流动做出准确的预测，这反过来将有助于我们设计和控制相关过程。然而，预测流体在多孔介质中的流动仍然是一个长期存在的问题。虽然观察简单的二维多孔介质中的流体流动可以很简单，但在更现实的三维情况下就不是这样了。这一建议旨在进行一项综合的计算和实验研究，以更准确地描述流动路径和真实的流体流动以及在此类材料中产生的变形。尽管非破坏性三维成像已经提供了许多关于多孔材料中流体分布的信息，但是快速和经济有效的四维孔尺度可视化(即在一段时间内)仍然是非常困难、昂贵和耗时的。此外，尽管在二维模型中对多孔介质中多相流的可视化进行了广泛的研究，但在四维(甚至三维)模型中进行此类研究的还很少。该方案的一个目标是开发一种4D方法，用于显示透明多孔介质中的两相流动及其在蠕动流动以外的介质中引起的变形，即当流动非常缓慢时。这一目标将通过从不同角度收集2D图像来实现，然后将这些图像与计算算法一起使用来构建多相流的高度详细的4D图像。将进行详细的计算，其中两相流体流动和由此产生的变形将在相同的多孔介质中进行模拟，而不是蠕动流动。研究人员还将研究和确定从达西区域到Forchheimer区域并最终发生湍流转变的临界雷诺数(Re)。此外，还将研究润湿性对两相流动中多孔介质变形的影响。该项目由流体动力学计划和既定的激励竞争研究计划(EPSCoR)联合资助。该奖项反映了NSF的法定使命，通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Porous media (e.g., sponge, paper, fabrics, rock, and soil) are materials with pores distributed in a solid matrix. When pores are connected, fluids can flow through them. Understanding and predicting fluid flow in porous media is important as it occurs in a wide range of applications, from contamination of groundwater and soil to printing on paper and fabrics. By understanding flow pathways, we can make accurate predictions of the fluid flow, which in turn, will help us design and control related processes. However, predicting fluid flow in porous media is still a long-standing problem. While observing fluid flow in simple two-dimensional porous media can be straightforward, the same is not true in more realistic three-dimensional cases. This proposal aims to carry out an integrated computational and experimental study to provide a more accurate description of flow pathways and realistic fluid flow and the resultant deformations in such materials. Although non-destructive 3D imaging has provided much information about fluid distribution in porous materials, fast and cost-effective 4D pore-scale visualization (i.e., over a period of time) is still very difficult, costly and time-consuming. Furthermore, although visualization of multiphase flow in porous media has been extensively studied in 2D models, there have been very few of such studies in 4D (or even 3D). One goal of this proposal is to develop a 4D method for visualization of two-phase flow in transparent porous media and the deformation that it induces in the media beyond the realm of creeping flow, i.e. when the flow is very slow. This goal will be achieved by collecting 2D images from various angles, which will then be used with a computational algorithm to build a highly detailed 4D image of the multiphase flow. Detailed computations will be carried out in which the two-phase fluid flow and the resulting deformation will be simulated in the same porous media beyond creeping flow. The investigators will also study and identify the critical Reynolds number (Re) at which the transition from the Darcy regime to Forchheimer and eventually turbulent flows occurs. The effect of wettability on the deformation of porous media during two-phase flow will also be investigated. Distinct deformation modes of a porous medium will also be examined under a wide range of Reynolds number and wettability conditions.This project is jointly funded by the Fluid Dynamics program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.