Feedback Coupling Between Flow and Reactions in Heterogeneous Porous and Fractured Media:Computational and Experimental Studies (CAREER)

小行星9734404 在多孔和裂缝介质中的反应-输运-流动耦合的特定领域提出了一个综合的研究和教育计划。 该研究计划的重点是可溶性岩石中裂缝的溶解生长以及沉淀/溶解反应对多孔和裂缝介质渗透率的影响的计算和实验研究。 教育计划涉及与流体力学和水文学教育相关的观测部分的开发，以及与水文科学研究生课程相关的课程开发。 流体流动和化学反应之间的反馈耦合在几种地质过程（例如岩溶中的管道和洞穴形成）和工程应用（例如“酸化”以增加石油采收的渗透率）的背景下是重要的。 虽然反应流耦合已经检查了以前，地质非均匀性的非线性耦合动力学的影响的系统研究才刚刚开始。 P.I.进行的一项初步研究。一名研究生指出，裂缝孔径的随机变化加速了方解石中导管的生长，最高可达一个数量级。 拟议的研究的目的是量化的非均匀性的多孔和裂缝介质中的流动反应耦合的动力学的影响，基于控制实验和计算研究。 实验将在用巴黎浇铸的骨折处进行。 将使用具有测量粗糙度的表面组装断裂。 高分辨率孔径测量（通过与Sandia国家实验室的Robert J. Glass博士合作）将伴随溶出实验。 计算研究将侧重于岩溶演化、石膏和硬石膏的溶解、裂缝中石英脉的沉积和碳酸盐结核的生长等专题系统。 对碳酸盐结核的研究将支持马特·戴维斯（Matt Davis）博士和彼得·莫兹利（Peter Mozley）博士的工作。 从他们的工作中获得的关于结核生长历史和方向的数据将被用来评估关于结核生长的不同假设。 继续教育活动包括开发交互式本科流体力学课程和用于定性和定量可视化的台式分水岭模块。 拟议的模块开发活动侧重于简单的实验，以说明多孔和裂缝介质中的流动和运输过程的非均质性的影响。 课程开发涉及一个新的综合课程反应输运模型，作为水文科学研究生课程的核心课程。 该课程将提供关于大气，海洋，地表和地下水系统中反应-传输相互作用的综合观点，强调不同介质的统一方面。 感兴趣的空间/时间尺度与所用模型类型之间的关系也将是一个主题。 该课程将包括一个关于小溪流水质实验性改变的实地部分（通过与Diane McKnight博士合作）和实验研究。

9734404 Rajaram An integrated research and education plan is proposed in the specific area of reaction-transport-flow coupling in porous and fractured media. The research plan focuses on computational and experimental studies of the dissolutional growth of fissures in soluble rock and the impact of precipitation/dissolution reactions on permeability of porous and fractured media. The educational plan involves the development of observational components relevant to education in fluid mechanics and hydrology, and curriculum development relevant to the graduate program in hydrologic sciences. Feedback coupling between fluid flow and chemical reactions is important in the context of several geological processes such as conduit and cave formation in karst, and engineering applications such as "acidization" to increase permeability for oil recovery. Although reaction-flow coupling has been examined previously, a systematic study of the influence of geologic heterogeneity on the nonlinearly coupled dynamics is only beginning. A preliminary study carried out by the P.I. and a graduate student indicated that random variations in the fissure aperture accelerate conduit growth in calcite by up to an order of magnitude. The objective of the proposed research is to quantify the influence of heterogeneity on the dynamics of flow-reaction coupling in porous and fractured media, based on controlled experiments and computational studies. Experiments will be carried out in fractures cast with plaster-of-paris. Surfaces with measured roughness will be used to assemble the fractures. High-resolution aperture measurements (through collaboration with Dr. Robert J. Glass, Sandia National Laboratories) will accompany dissolution experiments. Computational studies will focus on topical systems such as karst evolution, dissolution of gypsum and anhydrite, deposition of quartz veins in fractures and the growth of carbonate concretions. The studies on carbonate concretions will support the work of Drs. Matt Davis (EAR-9725194) and Peter Mozley (EAR-9726416). The data on concretion growth history and orientation obtained from their work will be employed to evaluate different hypotheses on concretion growth. Continuing educational activities include development of an interactive undergraduate fluid mechanics course and a bench-top watershed module to be used for qualitative and quantitative visualization. Proposed module development activities focus on simple experiments to illustrate the impact of heterogeneity on flow and transport processes in porous and fractured media. Curriculum development involve a new integrative course on reactive transport modeling, to serve as a core course for the graduate program in hydrologic sciences. The course will provide an integrated perspective on reaction-transport interactions in atmospheric, oceanic, surface and groundwater systems, emphasizing the unifying aspects across different media. The relationship between spatial/temporal scales of interest and the types of models used will also be a theme. The course will include a field component on experimental modification of water quality in small streams (through collaboration with Dr. Diane McKnight) and experimental studies.