Anisotropic Dispersion and Variable-Density Flow in Fractured Media

破裂介质中的各向异性色散和变密度流

• 批准号: 9814820
• 负责人: Frank Schwartz
• 金额: $ 30万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814820&HistoricalAwards=false
• 关键词: Anisotropic; Dispersion; Variable; Density; Flow

9814820Schwartz This study proposes to investigate anisotropic dispersion in fractured media and convective mixing associated with variable-density flow. It is generally not appreciated that the pattem of mixing in fractured systems can be anisotropic, as determined by the geometry of the fracture network, and can deviate from the classical isotropic theory. In terms of unstable mixed flows in fractured rocks, results are limited to a few studies. There are significant opportunities with our proposed study to contribute ftmdamental knowledge to physical mass transport in fractured rock systems.The goal is to elucidate processes of physical mass transport in fractured rock systems - how dispersion and convective dispersion are influenced by characteristics of the fracture geometry. To achieve this goal we propose to conduct both physical and numerical model studies of mass transport in 2-D and 3-D systems with complex fracture geometries. We are interested in exploring the conditions under which anisotropic dispersion develops and is manifest in variable-density systems.The study is organized around four different tasks. Task I involves a series of laboratory experiments with 2-D fractured systems. Task 2 extends the 3-D variable-density code MITSU3D to fracture networks with permeable matrix blocks. Task 3 is designed to study physical mass transport experimentally in a well-characterized 3-D fracture network. Task 4 is a complimentary model study designed to use the experimental results in conjunction with MITSU3D to develop appropriate methods to seed instabilities.The proposed study will contribute to knowledge by: (i) providing ftindainental new knowledge concerning the nature of dispersion and convective dispersion in fractured rock systems, (ii) developing and applying new capabilities for the physical modeling of mass transport in complex fractured rock systems, and for visualizing tracer distributions in three dimensions, and, (iii) developing and applying new modeling approaches for discrete-fracture systems, which can accommodate complexities in network geometry and in processes.

9814820 Schwartz本研究旨在研究裂隙介质中的各向异性弥散以及与变密度流相关的对流混合。 通常不理解的是，裂缝系统中的混合模式可以是各向异性的，如由裂缝网络的几何形状所确定的，并且可以偏离经典的各向同性理论。 就破碎岩石中的不稳定混合流而言，结果仅限于少数研究。 我们提出的研究有很大的机会为裂隙岩石系统中的物理质量输运提供基础知识，目的是阐明裂隙岩石系统中的物理质量输运过程--弥散和对流弥散如何受裂隙几何特征的影响。 为了实现这一目标，我们建议进行物理和数值模型研究的质量输运在2-D和3-D系统具有复杂的裂缝几何形状。 我们有兴趣探索各向异性色散的发展条件，并在变密度系统中表现出来。 任务一涉及一系列的实验室实验与2-D裂缝系统。 任务2扩展了三维变密度代码MITSU 3D的裂缝网络渗透矩阵块。 任务3的目的是研究物理质量输运实验在一个良好的特点3-D裂缝网络。 任务4是一项补充模型研究，旨在利用实验结果与MITSU 3D结合开发适当的方法来播种不稳定性。拟议的研究将通过以下方式贡献知识：（i）提供有关断裂岩石系统中弥散和对流弥散性质的基本新知识，（ii）开发和应用新的能力，对复杂的断裂岩石系统中的物质输运进行物理建模，并使三维示踪剂分布可视化，以及（iii）为离散裂缝系统开发和应用新的建模方法，这可以适应网络几何形状和过程中的复杂性。