mirror of
https://github.com/OPM/opm-simulators.git
synced 2024-12-25 16:51:00 -06:00
89 lines
3.2 KiB
C++
89 lines
3.2 KiB
C++
/*
|
||
Copyright 2015, 2016 SINTEF ICT, Applied Mathematics.
|
||
Copyright 2016 Statoil AS.
|
||
|
||
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/>.
|
||
*/
|
||
|
||
|
||
#include <opm/autodiff/multiPhaseUpwind.hpp>
|
||
#include <algorithm>
|
||
#include <utility>
|
||
|
||
|
||
namespace Opm
|
||
{
|
||
|
||
|
||
std::array<double, 3> connectionMultiPhaseUpwind(const std::array<double, 3>& head_diff,
|
||
const std::array<double, 3>& mob1,
|
||
const std::array<double, 3>& mob2,
|
||
const double transmissibility,
|
||
const double flux)
|
||
{
|
||
// Based on the paper "Upstream Differencing for Multiphase Flow in Reservoir Simulation",
|
||
// by Yann Brenier and Jérôme Jaffré,
|
||
// SIAM J. Numer. Anal., 28(3), 685–696.
|
||
// DOI:10.1137/0728036
|
||
//
|
||
// Notation is based on this paper, except q -> flux, t -> transmissibility.
|
||
|
||
enum { NumPhases = 3 }; // TODO: remove this restriction.
|
||
|
||
// Get and sort the g values (also called "weights" in the paper) for this connection.
|
||
using ValueAndIndex = std::pair<double, int>;
|
||
std::array<ValueAndIndex, NumPhases> g;
|
||
for (int phase_idx = 0; phase_idx < NumPhases; ++phase_idx) {
|
||
g[phase_idx] = ValueAndIndex(head_diff[phase_idx], phase_idx);
|
||
}
|
||
std::sort(g.begin(), g.end());
|
||
|
||
// Compute theta and r.
|
||
// Paper notation: subscript l -> ell (for read/searchability)
|
||
// Note that since we index phases from 0, r is one less than in the paper.
|
||
std::array<double, NumPhases> theta;
|
||
int r = -1;
|
||
for (int ell = 0; ell < NumPhases; ++ell) {
|
||
theta[ell] = flux;
|
||
for (int j = 0; j < NumPhases; ++j) {
|
||
if (j < ell) {
|
||
theta[ell] += transmissibility * (g[ell].first - g[j].first) * mob2[g[j].second];
|
||
}
|
||
if (j > ell) {
|
||
theta[ell] += transmissibility * (g[ell].first - g[j].first) * mob1[g[j].second];
|
||
}
|
||
}
|
||
if (theta[ell] <= 0.0) {
|
||
r = ell;
|
||
} else {
|
||
break; // r is correct, no need to continue
|
||
}
|
||
}
|
||
|
||
// Set upwind array and return.
|
||
std::array<double, NumPhases> upwind;
|
||
for (int ell = 0; ell < NumPhases; ++ell) {
|
||
const int phase_idx = g[ell].second;
|
||
upwind[phase_idx] = ell > r ? 1.0 : -1.0;
|
||
}
|
||
return upwind;
|
||
|
||
}
|
||
|
||
|
||
} // namespace Opm
|
||
|