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)对多孔介质中流体和溶质流动的作用进行综合研究，特别要注意这些变量如何与低饱和度现象有关。其主要目的是以微米级分辨率成像和量化这些界面特征，并随后使用测量结果与现有理论和新理论以及新的孔隙尺度数值模型的发展进行比较和进步。因此，我们预计能够改进理论和数值模型，以更好地包括界面特征，并更好地了解它们在多相流和输运中的作用。在孔隙尺度上彻底了解这些特征将使我们能够约束多相流理论，从而能够基于合理的热力学原理来实现宏观尺度的描述。直接求解微观尺度的守恒方程在理论上是可能的，但由于孔隙空间的复杂几何形状，对于任何实际系统来说，在实践中都是不可能的。因此，有必要采用平均程序来改变比例尺，以便可以应用控制方程。一个复杂的孔隙尺度的几何形状及其相关的流体分布可以使用格子-玻尔兹曼方法进行最佳模拟，使我们能够在理论之外使用数值模拟来研究平均过程。通过改进我们在孔隙尺度上的洞察，使用理论和数值模拟方法，我们将能够更好地制定合理的宏观描述，这将是朝着更大规模预测方向迈出的中间步骤，例如与清理地下污染物、改进农业灌溉和施肥措施以及提高石油采收率有关的预测。将实验、理论和模拟集成在一个项目中，为建立具有预测能力的现场尺度多相流模型提供了良好的基础。像这里建议的那样详细地测量界面性质在最近才变得在技术上可行，将这些信息纳入理论和数值模型中将为相关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.