Collaborative Research: Interfacial Dynamics in Multi-Phase Flow and Transport Processes

我们建议对界面特征（面积、曲率和薄膜）在多孔介质中流体和溶质流动中的作用进行综合研究，特别注意这些变量与低饱和度现象的关系。主要目的是以微米分辨率对这些界面特征进行成像和量化，并随后使用测量结果来比较和推进现有的和新的理论，以及新的孔隙尺度数值模型的发展。因此，我们期望能够改进理论和数值模型，以更好地包括界面特征，并更好地理解它们在多相流和输运中的作用。在孔隙尺度上对这些特征的透彻理解将使我们能够约束多相流理论，以便基于健全的热力学原理实现宏观尺度的描述。在微观尺度上直接求解守恒方程在理论上是可能的，但由于孔隙空间的复杂几何结构，在实践中对任何实际系统都是不可能的。因此，有必要采用平均程序来改变尺度，使控制方程能够适用。使用晶格-玻尔兹曼方法可以对复杂的孔隙尺度几何及其相关的流体分布进行最佳模拟，使我们能够在理论之外使用数值模拟来研究平均过程。通过使用理论和数值模拟方法，提高我们在孔隙尺度上的洞察力，我们将处于一个更好的位置，以发展一个完善的宏观描述，这将是朝着更大规模预测方向迈出的中间步骤，例如那些与地下污染物清理有关的预测，改善农业灌溉和施肥实践，以及提高石油采收率的问题。将实验、理论和模拟整合到一个项目中，为建立具有预测能力的多相流现场尺度模型提供了良好的基础。像这里所建议的这样详细地测量界面性质直到最近才在技术上变得可行，并且在理论和数值模型中结合这些信息将为所涉及的过程提供关键的新见解。

Gray0337535We propose to conduct an integrated study of the role of interfacial characteristics (area, curvature, and thin films) on the flow of fluids and solutes in porous media, with particular attention to how these variables pertain to low saturation phenomena. The principle aim is to image and quantify these interfacial characteristics with micron resolution and subsequently use the measurements for comparison to and advancement of existing and new theory, as well as new pore-scale numerical model developments. As a result, we anticipate being able to improve both theory and numerical models to better include interfacial features and obtain an improved understanding of their role in multi-phase flow and transport. A thorough understanding of these features at the pore scale will allow us to constrain multi-phase flow theory such that a macroscale description can be achieved based on sound thermodynamic principles. The direct solution of conservation equations at the microscale is possible in theory, but impossible in practice for any real system due to the complex geometry of the pore space. Thus it is necessary to employ an averaging procedure to change the scale such that the governing equations can be applied. A complex pore-scale geometry and its associated distribution of fluids can be optimally simulated using the Lattice-Bolzmann approach, allowing us to investigate the averaging procedure using numerical simulations in addition to theory. By improving our insight at the pore-scale, using both theoretical and numerical modeling approaches, we will be in a far better position for developing a sound macroscopic description, which will be an intermediate step in the direction of larger scale predictions, such as those pertaining to clean-up of contaminants in the subsurface, improved agricultural irrigation and fertilization practices, as well as issues in enhanced oil recovery. Integration of experiments, theory, and simulation in a single project offers the best hope of developing a sound fundamental basis on which to build field scale models of multiphase flow that have predictive capability. Measuring interfacial properties in such detail as suggested here has only recently become technically feasible, and the incorporation of this information in both theory and numerical models is going to provide critical new insight into the processes involved.