PorousMedia Class

This class defines a porous media object with various physical and mechanical properties. It includes methods for setting and retrieving these properties, as well as performing calculations related to porous media behavior.

Contents

Methods

Author

Danilo Cavalcanti

Version History

Version 1.00.

Class Definition

classdef PorousMedia < handle

Public attributes

    properties (SetAccess = public, GetAccess = public)
        id                   = '';
        Young                = [];              % Young modulus (Pa)
        nu                   = [];              % Poisson ratio
        sy0                  = [];              % Initial yield stress (Pa)
        Kp                   = [];              % Plastic modulus (Pa)
        cohesion             = [];              % Cohesion (Pa)
        frictionAngle        = [];              % Friction angle (rad)
        dilationAngle        = [];              % Dilation angle (rad)
        stressIntAlgorithm   = 'implicit';      % Stress integration algorithm
        MCmatch              = 'planestrain';   % How the DP surfaces match the MC ones
        friction             = [];              % Friction coefficient
        asympt               = [];              % Asymptotic model
        eref                 = [];              % Reference strain for asymptotic model
        sy                   = [];              % Isotropic tensile limit (Pa)
        tauy                 = [];              % Shear yield stress (Pa)
        kappa                = [];              % Ratio between the uniaxial compressive strength and the uniaxial tensile strength
        DamageThreshold      = [];              % Damage threshold
        FractureEnergyMode1  = [];              % Fracture energy associated with mode 1 (N/m)
        rho                  = [];              % Density (kg/m3)
        K                    = 0.0;             % Intrinsic permeability (m2)
        phi                  = 0.0;             % Porosity
        biot                 = 1.0;             % Biot's coefficient
        Ks                   = 1.0e25;          % Solid bulk modulus (Pa)
        Slr                  = 0.0;             % Residual liquid saturation
        Sgr                  = 0.0;             % Residual gas saturation
        Pb                   = 0.0;             % Gas-entry pressure (Pa)
        lambda               = 0.0;             % Curve-fitting parameter
        liqRelPermeability   = 'BrooksCorey';   % Liquid relative permeability
        gasRelPermeability   = 'BrooksCorey';   % Gas relative permeability
        capillaryPressure    = 'BrooksCorey';   % Saturation degree function
        mechanical           = 'elastic';       % Mechanical constitutive law
        b                    = [0.0;-1.0];      % Gravity force direction vector
        SlPc_umat            = [];              % User material curve saturation law
        klr_umat             = [];              % User material curve liquid relative permeability
        kgr_umat             = [];              % User material curve gas relative permeability
        m                    = 1;               % Expoent for the polynomial relationships
    end
    properties (SetAccess = protected, GetAccess = public)
        klrmin               = 1.0e-9;          % Minimum liquid relative permeability
        kgrmin               = 1.0e-9;          % Minimum gas relative permeability
    end

Constructor method

    methods
        %------------------------------------------------------------------
        function this = PorousMedia(id, permeability, porosity, ...
                biotCoefficient, solidBulkModulus, ...
                residualLiquidSaturationDegree, ...
                residualGasSaturationDegree,...
                gasEntryPressure,curveFittingParameter, ...
                liqRelPermeability, gasRelPermeability, ...
                capillaryPressure)
            if nargin == 1, this.id = id; end
            if nargin > 1
                this.id                   = id;
                this.K                    = permeability;
                this.phi                  = porosity;
                this.biot                 = biotCoefficient;
                this.Ks                   = solidBulkModulus;
                this.Slr                  = residualLiquidSaturationDegree;
                this.Sgr                  = residualGasSaturationDegree;
                this.Pb                   = gasEntryPressure;
                this.lambda               = curveFittingParameter;
                this.liqRelPermeability   = liqRelPermeability;
                this.gasRelPermeability   = gasRelPermeability;
                this.capillaryPressure    = capillaryPressure;
            end
        end
    end

Public methods

    methods
        % -----------------------------------------------------------------
        % Compute the effective saturation degree
        function Se = effectiveSaturationDegree(this,Sl)
            Se = (Sl - this.Slr)/(1.0 - this.Slr - this.Sgr);
        end

        % -----------------------------------------------------------------
        % Create the intrinsic permeability matrix
        function Km = intrinsicPermeabilityMatrix(this)
            Km = this.K * eye(2);
        end

        % -----------------------------------------------------------------
        % Set the minimum liquid relative permeability
        function setMinLiquidRelPermeability(this,klrmin)
            this.klrmin = klrmin;
        end

        % -----------------------------------------------------------------
        % Set the minimum gas relative permeability
        function setMinGasRelPermeability(this,kgrmin)
            this.kgrmin = kgrmin;
        end

        % -----------------------------------------------------------------
        % Set the user defined capillary pressure curve
        function setUMATCapillaryPressureCurve(this,curve)
            curve = sortrows(curve, 2);
            this.SlPc_umat = curve;
        end

        % -----------------------------------------------------------------
        % Set the user defined liquid relative permeability curve
        function setUMATLiquidRelPermCurve(this,curve)
            curve = sortrows(curve, 1);
            this.klr_umat = curve;
        end

        % -----------------------------------------------------------------
        % Set the user defined gas relative permeability curve
        function setUMATGasRelPermCurve(this,curve)
            curve = sortrows(curve, 1);
            this.kgr_umat = curve;
        end

        % -----------------------------------------------------------------
        % Set the mecahnical constitutive law
        function setMechanicalConstitutiveLaw(this,law)
            this.mechanical = law;
        end

        % -----------------------------------------------------------------
        % Set the mechanical properties of the material
        function setMechanicalProperties(this,E,nu)
            this.Young = E;
            this.nu = nu;
        end

        % -----------------------------------------------------------------
        % Set the density of the material
        function setDensity(this,rho)
            this.rho = rho;
        end

        % -----------------------------------------------------------------
        % Get the density of the material
        function rho = getDensity(this)
            rho = this.rho;
        end
    end

end

Published with MATLAB® R2022a