opm-simulators/opm/autodiff/MSWellHelpers.hpp

/*
  Copyright 2017 SINTEF Digital, Mathematics and Cybernetics.
  Copyright 2017 Statoil ASA.

  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 3 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/>.
*/


#ifndef OPM_MSWELLHELPERS_HEADER_INCLUDED
#define OPM_MSWELLHELPERS_HEADER_INCLUDED

#include <dune/istl/solvers.hh>
#include <cmath>

namespace Opm {

namespace mswellhelpers
{

    // obtain y = D^-1 * x
    template<typename MatrixType, typename VectorType>
    VectorType
    invDX(const MatrixType& D, VectorType x)
    {
        // the function will change the value of x, so we should not use reference of x here.

        // TODO: store some of the following information to avoid to call it again and again for
        // efficiency improvement.
        // Bassically, only the solve / apply step is different.

        VectorType y(x.size());
        y = 0.;

        Dune::MatrixAdapter<MatrixType, VectorType, VectorType> linearOperator(D);

        // Sequential incomplete LU decomposition as the preconditioner
        Dune::SeqILU0<MatrixType, VectorType, VectorType> preconditioner(D, 1.0);

        // Preconditioned BICGSTAB solver
        Dune::BiCGSTABSolver<VectorType> linsolver(linearOperator,
                                                   preconditioner,
                                                   1.e-6, // desired residual reduction factor
                                                   50, // maximum number of iterations
                                                   0); // verbosity of the solver

        // Object storing some statistics about the solving process
        Dune::InverseOperatorResult statistics ;

        // Solve
        linsolver.apply(y, x, statistics );

        return y;
    }





    static double haalandFormular(const double re, const double diameter, const double roughness)
    {
        const double value = std::exp(10. / 9. * std::log(roughness / (3.7 * diameter)) );
        return -3.6 * std::log10( 6.9 / re + value);
    }





    static double calculateFrictionFactor(const double area, const double diameter,
                                          const double w, const double roughness, const double mu)
    {

        double f = 0.;
        // Reynolds number
        const double re = std::abs(diameter * w / (area * mu));

        assert(re > 0.0);

        const double re_value1 = 200.;
        const double re_value2 = 4000.;

        if (re < re_value1) {
            f = 16. / re;
        } else if (re > re_value2){
            f = haalandFormular(re, diameter, roughness);
        } else { // in between
            const double f1 = 16. / re_value1;
            const double f2 = haalandFormular(re_value2, diameter, roughness);

            f = (f2 - f1) / (re_value2 - re_value1) * (re - re_value1) + f1;
        }
        return f;
    }






    // TODO: not sure whether mu, density and mass flow rate should be Evaluation
    // only use its value for now.
    // l is the segment length
    // area is the segment cross area
    // diameter is the segment inner diameter
    // w is mass flow rate through the segment
    // density is density
    // roughness is the absolute roughness
    // mu is the average phase viscosity
    template <class ValueType>
    ValueType frictionPressureLoss(const double l, const double diameter, const double area, const ValueType& density,
                                   const ValueType& w, const double roughness, const ValueType& mu)
    {
        const double f = calculateFrictionFactor(area, diameter, w.value(), roughness, mu.value());
        return f * l * w * w / (area * area * diameter * density);
    }




} // namespace mswellhelpers

}

#endif