scholarly journals Flexible parallel implicit modelling of coupled thermal–hydraulic–mechanical processes in fractured rocks

Solid Earth ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 921-941 ◽  
Author(s):  
Mauro Cacace ◽  
Antoine B. Jacquey
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Object Oriented ◽  
Coupled System ◽  
Weak Sense ◽  
Rock Properties ◽  
Solid Matrix ◽  
Scaling Parameters ◽  
Active Processes ◽  
Element Technique

Abstract. Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture–solid matrix system. The coupled system of equations is implemented in a new simulator code that makes use of a Galerkin finite-element technique. The code builds on a flexible, object-oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel and implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (either by classical Newton–Raphson or by free Jacobian inexact Newton–Krylow schemes) on an underlying unstructured mesh. Nonlinear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimetres to tens of kilometres) and temporal scales (from minutes to hundreds of years).

scholarly journals Flexible parallel implicit modelling of coupled Thermal-Hydraulic-Mechanical processes in fractured rocks

2017 ◽  
Author(s):  
Mauro Cacace ◽  
Antoine B. Jacquey
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Object Oriented ◽  
Coupled System ◽  
Weak Sense ◽  
Rock Properties ◽  
Solid Matrix ◽  
Scaling Parameters ◽  
Active Processes ◽  
Element Technique

Abstract. Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture-solid matrix system. The coupled system of equations is implemented into a new simulator code that makes use of a Galerkin Finite Element technique. The code builds on a flexible, object oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel, implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport and rock deformation are solved in a weak sense (either by classical Newton- Raphson or by Free Jacobian Inexact Newton Krylow schemes) on an underlying unstructured mesh. Non-linear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state for the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimeters to tens of kilometers) and temporal scales (from minutes to hundreds of years).

scholarly journals Mathematical analysis of hydrodynamics and tissue deformation inside an isolated solid tumor

2018 ◽  
Vol 45 (2) ◽  
pp. 253-278 ◽  
Author(s):  
Meraj Alam ◽  
Bibaswan Dey ◽  
Sekhar Raja
Keyword(s):  
Solid Tumor ◽  
Solid Phase ◽  
Fluid Motion ◽  
Extracellular Fluid ◽  
Mixture Theory ◽  
Coupled System ◽  
Weak Sense ◽  
Governing Equations ◽  
One Dimensional ◽  
2D And 3D

In this article, we present a biphasic mixture theory based mathematical model for the hydrodynamics of interstitial fluid motion and mechanical behavior of the solid phase inside a solid tumor. The tumor tissue considered here is an isolated deformable biological medium. The solid phase of the tumor is constituted by vasculature, tumor cells, and extracellular matrix, which are wet by a physiological extracellular fluid. Since the tumor is deformable in nature, the mass and momentum equations for both the phases are presented. The momentum equations are coupled due to the interaction (or drag) force term. These governing equations reduce to a one-way coupled system under the assumption of infinitesimal deformation of the solid phase. The well-posedness of this model is shown in the weak sense by using the inf-sup (Babuska?Brezzi) condition and Lax?Milgram theorem in 2D and 3D. Further, we discuss a one-dimensional spherical symmetry model and present some results on the stress fields and energy of the system based on ??2 and Sobolev norms. We discuss the so-called phenomena of ?necrosis? inside a solid tumor using the energy of the system.

Thermophysical reservoir properties of the Hauptdolomit-facies underneath the Viennese basin across fault zones analogues – a reservoir study for the GeoTief EXPLORE project

2020 ◽  
Author(s):  
Doris Rupprecht ◽  
Sven Fuchs ◽  
Andrea Förster ◽  
Mariella Penz-Wolfmayr
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Fractured Rocks ◽  
Damage Zone ◽  
Fault Zones ◽  
Rock Properties ◽  
Zone Model ◽  
Geothermal Resources ◽  
Fault Rocks ◽  
The Impact

<p>The GeoTief EXPLORE project aims to explore the geothermal potential and quantify the geothermal resources of the Vienna Basin (Austria) and the underlying Northern Calcareous Alpine basement. The main target of geothermal interest is the massive and tectonically remolded Hauptdolomite facies that has been identified as potential geothermal reservoir in previous studies. Now, this formation is studied using outcrop analogues for the investigation of their petrophysical characterization and specific thermal properties (thermal conductivity and thermal diffusivity).</p><p> </p><p>Here, we report new measurements on a total of 60 samples from 6 outcrops in and around the area of Vienna applying different methods for the laboratory measurement of thermal and hydraulic rock properties. The petrophysical analysis considers the impact of deformation along and across fault zones, which introduces heterogeneity of storage properties and consequently in the thermophysical properties. Using the standard fault core and damage zone model, outcrop samples were grouped into unfractured and fractured protoliths, as well as in fault rocks, like breccias and cataclasites. Rock samples are then classified by their fracture density (m² fracture surface per m³ rock) and by their matrix content and differences in grain sizes, respectively.</p><p> </p><p>The measured thermal rock properties vary significantly between the selected rock groups. The total range [90 % of values] is between 3.2 and 5.0 W/(mK) for thermal conductivity and between 1.3 and 2.7 mm²/s for thermal diffusivity. The results generally met the expected trend for fractured rocks as conductivity and diffusivity decreases with increasing porosity under unsaturated and saturated conditions. The total porosities are less than 5%. The variability of thermal conductivity under saturated conditions shows complex trends depending on the different rock classifications where fault rocks and highly fractured rocks of the damage zone show lower increase in thermal conductivities.</p><p> </p><p>The new petrophysical characterization will be the base for further numerical investigations of the hydraulic and thermal regime as well as for the analysis of the geothermal resources of the Hauptdolomite.</p><p> </p><p> </p><p> </p><p> </p>

scholarly journals Modelling of Groundwater Flow in Fractured Rocks

2015 ◽  
Vol 25 ◽  
pp. 142-149 ◽  
Author(s):  
Gy. Karay ◽  
G. Hajnal
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks

scholarly journals Reviews of lnvestigation and Analysis methods for Groundwater Flow in Fractured Rocks

2002 ◽  
Vol 44 (2) ◽  
pp. 81-103 ◽  
Author(s):  
Masahito YOSHIMURA ◽  
Masayuki IMAIZUMI ◽  
Yasuo SAKURA ◽  
Changyuan TANG
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Analysis Methods

LONG-TERM INFLUENCE OF CONCRETE DEGRADATION ON DAM–FOUNDATION INTERACTION

2011 ◽  
Vol 08 (03) ◽  
pp. 397-423 ◽  
Author(s):  
A. BURMAN ◽  
D. MAITY ◽  
S. SREEDEEP ◽  
I. GOGOI
Keyword(s):  
Coupled System ◽  
Seismic Load ◽  
Dam Foundation ◽  
Ageing Model ◽  
Concrete Degradation ◽  
The Time Domain ◽  
Element Technique ◽  
Long Term Behavior ◽  
Ageing Procedure

The dam–foundation interaction behavior under the application of seismic load has been investigated in the present paper using finite element technique in the time domain. Since the dam face is in constant contact with water, concrete degradation due to hygromechanical loading is inevitable and should be considered in the analysis procedure. This ageing process of concrete leads to loss of stiffness and strength of the material. Therefore, to assess the behavior of the dam at a later stage of its life, it is important to determine the proper strength of the concrete at a certain age. An approach to include the time-dependent degradation of concrete owing to environmental factors and mechanical loading in terms of isotropic degradation index is presented. An iterative scheme has been developed to model the dam–foundation interaction effects of the coupled system. The strains and the displacements are observed to increase if the ageing procedure of the gravity dam is taken into account. The long-term behavior of the aged concrete gravity and foundation interaction has been observed by using a developed ageing model for concrete.

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