{"title":"Towards improved understanding of spontaneous imbibition into dry porous media using pore-scale direct numerical simulations","authors":"Luka Malenica, Zhidong Zhang, Ueli Angst","doi":"arxiv-2408.02831","DOIUrl":null,"url":null,"abstract":"Traditional approaches to mathematically describe spontaneous imbibition are\nusually based on either macro-scale models, such as Richards equation, or\nsimplified pore-scale models, such as the bundle of capillary tubes (BCTM) or\npore-network modeling (PNM). It is well known that such models cannot provide\nfull microscopic details of the multiphase flow processes and that many\npore-scale mechanisms still lack proper mathematical descriptions. To improve\nthe predictive capabilities of traditional models, a fundamental understanding\nof pore-scale dynamics is needed. The focus of this paper is obtaining detailed\ninsight and consistent explanation of particular processes during\ncapillary-controlled water imbibition into dry porous media. We use\ntwo-dimensional model geometries and perform fully dynamic volume-of-fluid\nbased direct numerical simulations of air-water multiphase flow at the\npore-scale, to study processes that generally are not considered in traditional\nmodels. More specifically, we investigate differences between converging and\ndiverging geometries, dynamic pressure and meniscus reconfiguration during\npore-filling events, and the influence of inertia and pore size on imbibition\ndynamics and the occurrence of capillary barriers. Furthermore, we perform a\ndetailed comparison between non-interacting and interacting BCTM and study the\nimpact of the narrow contractions on imbibition dynamics and the trapping of\nthe non-wetting phase. Obtained knowledge can be used to improve predictive\nmodels, which are broadly relevant considering the importance of spontaneous\nimbibition in many different natural and industrial processes.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.02831","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Traditional approaches to mathematically describe spontaneous imbibition are
usually based on either macro-scale models, such as Richards equation, or
simplified pore-scale models, such as the bundle of capillary tubes (BCTM) or
pore-network modeling (PNM). It is well known that such models cannot provide
full microscopic details of the multiphase flow processes and that many
pore-scale mechanisms still lack proper mathematical descriptions. To improve
the predictive capabilities of traditional models, a fundamental understanding
of pore-scale dynamics is needed. The focus of this paper is obtaining detailed
insight and consistent explanation of particular processes during
capillary-controlled water imbibition into dry porous media. We use
two-dimensional model geometries and perform fully dynamic volume-of-fluid
based direct numerical simulations of air-water multiphase flow at the
pore-scale, to study processes that generally are not considered in traditional
models. More specifically, we investigate differences between converging and
diverging geometries, dynamic pressure and meniscus reconfiguration during
pore-filling events, and the influence of inertia and pore size on imbibition
dynamics and the occurrence of capillary barriers. Furthermore, we perform a
detailed comparison between non-interacting and interacting BCTM and study the
impact of the narrow contractions on imbibition dynamics and the trapping of
the non-wetting phase. Obtained knowledge can be used to improve predictive
models, which are broadly relevant considering the importance of spontaneous
imbibition in many different natural and industrial processes.