{"title":"The free-energy density function and its complementary forms for porous media saturated by two non-miscible fluids under non isothermal conditions","authors":"A. Gajo","doi":"10.1016/j.gete.2024.100624","DOIUrl":null,"url":null,"abstract":"<div><div>This paper presents a general method for defining the macroscopic free-energy density function and its complementary forms for a porous medium saturated by two non-miscible fluids, in the case of compressible fluid and solid constituents, non-isothermal conditions and negligible interfacial surface energy.</div><div>The major advantage of the proposed approach is that no limitation or simplification is posed on the choice of the free energies of the fluid constituents. As a result, a fully non-linear equation of state for the pore fluids can be incorporated within the proposed framework.</div><div>The method is presented under the assumption that interfacial surface energy terms are negligible, thus recovering a Bishop parameter <span><math><mi>χ</mi></math></span> coinciding with the degree of saturation, which is expected to be applicable mostly to non-plastic soils. Moreover, small strains of the solid skeleton are assumed, but the method can be easily extended to a large strain formulation as discussed below. The paper analyzes also some particular cases concerning the incompressibility of all constituents, the geometric linearization and the incompressibility only of the solid constituent.</div><div>The knowledge of the free energy density function is the starting point for the evaluation of the dissipation function, of energy and entropy balance and, in general, for the formulation of thermodynamically consistent constitutive models.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"41 ","pages":"Article 100624"},"PeriodicalIF":3.3000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geomechanics for Energy and the Environment","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352380824000911","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
This paper presents a general method for defining the macroscopic free-energy density function and its complementary forms for a porous medium saturated by two non-miscible fluids, in the case of compressible fluid and solid constituents, non-isothermal conditions and negligible interfacial surface energy.
The major advantage of the proposed approach is that no limitation or simplification is posed on the choice of the free energies of the fluid constituents. As a result, a fully non-linear equation of state for the pore fluids can be incorporated within the proposed framework.
The method is presented under the assumption that interfacial surface energy terms are negligible, thus recovering a Bishop parameter coinciding with the degree of saturation, which is expected to be applicable mostly to non-plastic soils. Moreover, small strains of the solid skeleton are assumed, but the method can be easily extended to a large strain formulation as discussed below. The paper analyzes also some particular cases concerning the incompressibility of all constituents, the geometric linearization and the incompressibility only of the solid constituent.
The knowledge of the free energy density function is the starting point for the evaluation of the dissipation function, of energy and entropy balance and, in general, for the formulation of thermodynamically consistent constitutive models.
期刊介绍:
The aim of the Journal is to publish research results of the highest quality and of lasting importance on the subject of geomechanics, with the focus on applications to geological energy production and storage, and the interaction of soils and rocks with the natural and engineered environment. Special attention is given to concepts and developments of new energy geotechnologies that comprise intrinsic mechanisms protecting the environment against a potential engineering induced damage, hence warranting sustainable usage of energy resources.
The scope of the journal is broad, including fundamental concepts in geomechanics and mechanics of porous media, the experiments and analysis of novel phenomena and applications. Of special interest are issues resulting from coupling of particular physics, chemistry and biology of external forcings, as well as of pore fluid/gas and minerals to the solid mechanics of the medium skeleton and pore fluid mechanics. The multi-scale and inter-scale interactions between the phenomena and the behavior representations are also of particular interest. Contributions to general theoretical approach to these issues, but of potential reference to geomechanics in its context of energy and the environment are also most welcome.