Advances in Understanding Pore-Scale Dispersion

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项目编号	1521441
	Advances in Understanding Pore-Scale Dispersion
	Brian Wood
主持机构	Oregon State University
项目开始年	2015
	2015-06-15
项目结束日期	2018-05-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	384073(USD)
国家	美国
语种	英语
英文摘要	A porous medium is any material consisting of solids and voids (or pores). Sponges, beach sand, and furnace filters are familiar examples of porous materials (porous media). Other examples are petroleum reservoirs, aquifers that supply groundwater, and catalytic converters that reduce car emissions. With the recent advances in computer speed and power, scientists now have methods to simulate and understand the way that water and dissolved matter, as well as small particles, move through porous media. This can be used to help fabricate porous materials with specific useful qualities and to understand the behavior of natural porous materials. The way that chemicals spread in porous media as they flow though the intricate network of the pores is called dispersion. Dispersion is important because it influences how quickly chemical reactions and mass transfer happen at the solid interfaces of a porous material. For example, understanding of dispersion is essential to understanding how blood is oxygenated in the lungs during breathing. As a second example, understanding dispersion is important for understanding the spread and eventual cleanup of contaminants spilled into the subsurface. In this research, 3-dimensional X-ray images (much like a medical CAT scan) of real porous materials will be collected, and state-of-the-art computational methods will simulate the dispersion process within the porous media. This information will be useful in developing new theories for describing dispersion in porous materials, and this will have potential utility in engineering applications (such as filtration) and in fundamental science (such as understanding how our lungs work!) Although dispersion in porous media has been studies for over 100 years, the interaction of diffusion with the complex variations in the flow field within a porous medium are still not understood at the level of basic continuum mechanics. It has only recently become possible to conduct numerical simulations of flow within the geometry of a complex, three-dimensional porous medium of sufficient size and resolution to generate the kind of data needed to connect the microscale physical processes within a porous medium with the observable macroscopic behavior of the material as a whole. This research will combine theory, numerical computation, and experimental data to examine the process of dispersion in monodisperse and polydisperse porous media at an unprecedented level of detail. Because dispersion in porous media is relevant to a host of subsurface processes relevant to practicing hydrologists (e.g., bioremediation, contaminant spreading, mass transfer between rivers and the hyporheic zone), it is important to understand the dispersion process so that we can determine how it affects transport in the subsurface. This research also has applications to engineered systems outside of hydrology (such as chromatography and catalysis). The goal is to bring new understanding about the dispersion process by: 1) experimentally measuring (via X-ray tomography) beds of random porous media at unprecedented resolution; 2) conducting direct numerical simulations of the flow and dispersion process in these porous media (up through the steady inertial flow range) using state-of-the art numerical methods; and 3) developing modified descriptive theory (via the method of volume averaging) to predict the macroscopic behavior of the dispersion process from representative structure of porous materials.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68060
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Brian Wood.Advances in Understanding Pore-Scale Dispersion.2015.