richardsnewtonmethod.hh

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// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
  This file is part of the Open Porous Media project (OPM).
 
  OPM 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 2 of the License, or
  (at your option) any later version.
 
  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
 
  Consult the COPYING file in the top-level source directory of this
  module for the precise wording of the license and the list of
  copyright holders.
*/
#ifndef EWOMS_RICHARDS_NEWTON_METHOD_HH
#define EWOMS_RICHARDS_NEWTON_METHOD_HH
 
#include <dune/common/fvector.hh>
 
#include <opm/material/fluidstates/ImmiscibleFluidState.hpp>
 
#include <opm/models/common/multiphasebaseproperties.hh>
#include <opm/models/discretization/common/fvbasenewtonmethod.hh>
#include <opm/models/richards/richardsproperties.hh>
 
#include <algorithm>
 
namespace Opm {

template <class TypeTag>
class RichardsNewtonMethod : public GetPropType<TypeTag, Properties::DiscNewtonMethod>
{
    using ParentType = GetPropType<TypeTag, Properties::DiscNewtonMethod>;
 
    using Scalar = GetPropType<TypeTag, Properties::Scalar>;
    using PrimaryVariables = GetPropType<TypeTag, Properties::PrimaryVariables>;
    using EqVector = GetPropType<TypeTag, Properties::EqVector>;
    using FluidSystem = GetPropType<TypeTag, Properties::FluidSystem>;
    using MaterialLaw = GetPropType<TypeTag, Properties::MaterialLaw>;
    using MaterialLawParams = GetPropType<TypeTag, Properties::MaterialLawParams>;
    using Simulator = GetPropType<TypeTag, Properties::Simulator>;
    using Linearizer = GetPropType<TypeTag, Properties::Linearizer>;
 
    using Indices = GetPropType<TypeTag, Properties::Indices>;
    enum { pressureWIdx = Indices::pressureWIdx };
    enum { numPhases = FluidSystem::numPhases };
    enum { liquidPhaseIdx = getPropValue<TypeTag, Properties::LiquidPhaseIndex>() };
    enum { gasPhaseIdx = getPropValue<TypeTag, Properties::GasPhaseIndex>() };
 
    using PhaseVector = Dune::FieldVector<Scalar, numPhases>;
 
public:
    explicit RichardsNewtonMethod(Simulator& simulator)
        : ParentType(simulator)
    {}
 
protected:
    friend NewtonMethod<TypeTag>;
    friend ParentType;

    void updatePrimaryVariables_(unsigned globalDofIdx,
                                 PrimaryVariables& nextValue,
                                 const PrimaryVariables& currentValue,
                                 const EqVector& update,
                                 const EqVector&)
    {
        // normal Newton-Raphson update
        nextValue = currentValue;
        nextValue -= update;
 
        // do not clamp anything after 4 iterations
        if (this->numIterations_ > 4) {
            return;
        }
 
        const auto& problem = this->simulator_.problem();
 
        // calculate the old wetting phase saturation
        const MaterialLawParams& matParams =
            problem.materialLawParams(globalDofIdx, /*timeIdx=*/0);
 
        ImmiscibleFluidState<Scalar, FluidSystem> fs;
 
        // set the temperature
        const Scalar T = problem.temperature(globalDofIdx, /*timeIdx=*/0);
        fs.setTemperature(T);

        // calculate the phase pressures of the previous iteration
 
        // first, we have to find the minimum capillary pressure
        // (i.e. Sw = 0)
        fs.setSaturation(liquidPhaseIdx, 1.0);
        fs.setSaturation(gasPhaseIdx, 0.0);
        PhaseVector pC;
        MaterialLaw::capillaryPressures(pC, matParams, fs);
 
        // non-wetting pressure can be larger than the
        // reference pressure if the medium is fully
        // saturated by the wetting phase
        const Scalar pWOld = currentValue[pressureWIdx];
        const Scalar pNOld =
            std::max(problem.referencePressure(globalDofIdx, /*timeIdx=*/0),
                     pWOld + (pC[gasPhaseIdx] - pC[liquidPhaseIdx]));

        // find the saturations of the previous iteration
        fs.setPressure(liquidPhaseIdx, pWOld);
        fs.setPressure(gasPhaseIdx, pNOld);
 
        PhaseVector satOld;
        MaterialLaw::saturations(satOld, matParams, fs);
        satOld[liquidPhaseIdx] = std::max(Scalar{0.0}, satOld[liquidPhaseIdx]);

        // find the wetting phase pressures which
        // corrospond to a 20% increase and a 20% decrease
        // of the wetting saturation
        fs.setSaturation(liquidPhaseIdx, satOld[liquidPhaseIdx] - 0.2);
        fs.setSaturation(gasPhaseIdx, 1.0 - (satOld[liquidPhaseIdx] - 0.2));
        MaterialLaw::capillaryPressures(pC, matParams, fs);
        const Scalar pwMin = pNOld - (pC[gasPhaseIdx] - pC[liquidPhaseIdx]);
 
        fs.setSaturation(liquidPhaseIdx, satOld[liquidPhaseIdx] + 0.2);
        fs.setSaturation(gasPhaseIdx, 1.0 - (satOld[liquidPhaseIdx] + 0.2));
        MaterialLaw::capillaryPressures(pC, matParams, fs);
        const Scalar pwMax = pNOld - (pC[gasPhaseIdx] - pC[liquidPhaseIdx]);

        // clamp the result to the minimum and the maximum
        // pressures we just calculated
        const Scalar pW = std::clamp(nextValue[pressureWIdx], pwMin, pwMax);
        nextValue[pressureWIdx] = pW;
    }
};
 
} // namespace Opm
 
#endif