Pore-scale determination of parameters for macroscale modeling of evaporation processes in porous media
Pore-scale determination of parameters for macroscale modeling of evaporation processes in porous media
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DOI：
10.1029/2010wr009519
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发表时间：
2011-07-23
影响因子：
5.4
通讯作者：
Krafczyk, M.
中科院分区：
文献类型：
--
作者：
Ahrenholz, B.;Niessner, J.;Krafczyk, M.
蒸发是许多自然系统和技术系统的重要过程，如地下不饱和区或微通道蒸发器。多相流和输运过程的数值模拟是理解和预测相关过程的重要工具。为了准确地、基于物理的描述蒸发过程中发生的动力学相间质量和传热，数值模型必须考虑相间的界面面积。最近开发的多孔介质两相流模型能够通过使用界面面积作为模型中的参数来解释所涉及的过程。然而，关键问题是确定特定界面面积，毛细管压力和饱和度之间的关系。在本文中，我们提出了一个多相晶格玻尔兹曼模型，使我们能够确定这些关系。在扫描天然多孔介质几何形状的基础上，确定了比界面面积、毛细压力和饱和度之间的关系。据我们所知，这是第一次从孔隙尺度数据中获得流固比界面面积关系。利用这些函数，我们给出了蒸发器装置和多孔介质中干燥的宏观模拟结果。
Evaporation is an important process in many natural and technical systems, such as the unsaturated zone of the subsurface or microchannel evaporators. For the understanding and prediction of the involved processes, numerical simulations of multiphase flow and transport processes are an important tool. In order to achieve an accurate, physically based description of kinetic interphase mass and heat transfer occurring during evaporation, the numerical model has to account for the interfacial areas between phases. A recently developed model for two-phase flow in porous media is able to account for the involved processes by using interfacial areas explicitly as parameters in the model. The crucial issue, however, is the determination of the relationships between specific interfacial areas, capillary pressure, and saturation in this paper, we present a multiphase lattice Boltzmann model, which allows us to determine these relationships. On the basis of the scanned geometry of a natural porous medium, the relationships between specific interfacial areas, capillary pressure, and saturation are determined. To the best of our knowledge, this is the first time that fluid-solid specific interfacial area relationships have been obtained from pore-scale data. Using these functions, we present the results of macroscale simulations of an evaporator device and of drying in a porous medium.