regularizedbrookscorey.hh

Go to the documentation of this file.

// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*****************************************************************************
 *   See the file COPYING for full copying permissions.                      *
 *                                                                           *
 *   This program is free software: you can redistribute it and/or modify    *
 *   it under the terms of the GNU General Public License as published by    *
 *   the Free Software Foundation, either version 3 of the License, or       *
 *   (at your option) any later version.                                     *
 *                                                                           *
 *   This program is distributed in the hope that it will be useful,         *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of          *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the            *
 *   GNU General Public License for more details.                            *
 *                                                                           *
 *   You should have received a copy of the GNU General Public License       *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
 *****************************************************************************/
#ifndef REGULARIZED_BROOKS_COREY_HH
#define REGULARIZED_BROOKS_COREY_HH
 
#include "brookscorey.hh"
#include "regularizedbrookscoreyparams.hh"
 
#include <dumux/common/spline.hh>
 
namespace Dumux {
 
template <class ScalarT, class ParamsT = RegularizedBrooksCoreyParams<ScalarT> >
class RegularizedBrooksCorey
{
    using BrooksCorey = Dumux::BrooksCorey<ScalarT, ParamsT>;
 
public:
    using Params = ParamsT;
    using Scalar = typename Params::Scalar;
 
    static Scalar pc(const Params &params, Scalar swe)
    {
        const Scalar sThres = params.thresholdSw();
 
        // make sure that the capilary pressure observes a
        // derivative != 0 for 'illegal' saturations. This is
        // required for example by newton solvers (if the
        // derivative is calculated numerically) in order to get the
        // saturation moving to the right direction if it
        // temporarily is in an 'illegal' range.
        if (swe <= sThres) {
            Scalar m = BrooksCorey::dpc_dswe(params, sThres);
            Scalar pcsweLow = BrooksCorey::pc(params, sThres);
            return pcsweLow + m*(swe - sThres);
        }
        else if (swe > 1.0) {
            Scalar m = BrooksCorey::dpc_dswe(params, 1.0);
            Scalar pcsweHigh = BrooksCorey::pc(params, 1.0);
            return pcsweHigh + m*(swe - 1.0);
        }
 
        // if the effective saturation is in an 'reasonable'
        // range, we use the real Brooks-Corey law...
        return BrooksCorey::pc(params, swe);
    }
 
    static Scalar sw(const Params &params, Scalar pc)
    {
        const Scalar sThres = params.thresholdSw();
 
        // calculate the saturation which corrosponds to the
        // saturation in the non-regularized version of
        // the Brooks-Corey law
        Scalar swe = BrooksCorey::sw(params, pc);
 
        // make sure that the capilary pressure observes a
        // derivative != 0 for 'illegal' saturations. This is
        // required for example by newton solvers (if the
        // derivative calculated numerically) in order to get the
        // saturation moving to the right direction if it
        // temporarily is in an 'illegal' range.
        if (swe <= sThres) {
            // invert the low saturation regularization of pc()
            Scalar m = BrooksCorey::dpc_dswe(params, sThres);
            Scalar pcsweLow = BrooksCorey::pc(params, sThres);
            return sThres + (pc - pcsweLow)/m;
        }
        else if (swe > 1.0) {
            Scalar m = BrooksCorey::dpc_dswe(params, 1.0);
            Scalar pcsweHigh = BrooksCorey::pc(params, 1.0);
            return 1.0 + (pc - pcsweHigh)/m;
        }
 
        return BrooksCorey::sw(params, pc);
    }
 
    static Scalar endPointPc(const Params &params)
    { return params.pe(); }
 
    static Scalar dpc_dswe(const Params &params, Scalar swe)
    {
        const Scalar sThres = params.thresholdSw();
 
        // derivative of the regualarization
        if (swe <= sThres) {
            // calculate the slope of the straight line used in pc()
            Scalar m = BrooksCorey::dpc_dswe(params, sThres);
            return m;
        }
        else if (swe > 1.0) {
            // calculate the slope of the straight line used in pc()
            Scalar m = BrooksCorey::dpc_dswe(params, 1.0);
            return m;
        }
 
        return BrooksCorey::dpc_dswe(params, swe);
    }
 
    static Scalar dswe_dpc(const Params &params, Scalar pc)
    {
        const Scalar sThres = params.thresholdSw();
 
        //instead of return value = inf, return a very large number
        if (params.pe() == 0.0)
        {
            return 1e100;
        }
 
        // calculate the saturation which corresponds to the
        // saturation in the non-regularized version of the
        // Brooks-Corey law
        Scalar swe;
        if (pc < 0)
            swe = 1.5; // make sure we regularize below
        else
            swe = BrooksCorey::sw(params, pc);
 
        // derivative of the regularization
        if (swe <= sThres) {
            // calculate the slope of the straight line used in pc()
            Scalar m = BrooksCorey::dpc_dswe(params, sThres);
            return 1/m;
        }
        else if (swe > 1.0) {
            // calculate the slope of the straight line used in pc()
            Scalar m = BrooksCorey::dpc_dswe(params, 1.0);
            return 1/m;
        }
        return 1.0/BrooksCorey::dpc_dswe(params, swe);
    }
 
    static Scalar krw(const Params &params, Scalar swe)
    {
        if (swe <= 0.0)
            return 0.0;
        else if (swe >= 1.0)
            return 1.0;
 
        return BrooksCorey::krw(params, swe);
    }
 
    static Scalar krn(const Params &params, Scalar swe)
    {
        if (swe >= 1.0)
            return 0.0;
        else if (swe <= 0.0)
            return 1.0;
 
        return BrooksCorey::krn(params, swe);
    }
};
} // end namespace Dumux
 
#endif