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/* This file is part of the OpenLB library
*
* Copyright (C) 2006, 2007 Jonas Latt
* E-mail contact: info@openlb.net
* The most recent release of OpenLB can be downloaded at
* <http://www.openlb.net/>
*
* 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 2
* 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, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef FINITE_DIFFERENCE_2D_H
#define FINITE_DIFFERENCE_2D_H
#include "finiteDifference.h"
namespace olb {
namespace fd {
template<typename T, typename DESCRIPTOR,
int direction, int orientation,
bool orthogonal>
struct DirectedGradients2D {
static void interpolateVector(T velDeriv[DESCRIPTOR::d],
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY);
static void interpolateScalar(T& rhoDeriv,
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY);
};
// Implementation for orthogonal==true; i.e. the derivative is along
// the boundary normal.
template<typename T, typename DESCRIPTOR,
int direction, int orientation>
struct DirectedGradients2D<T, DESCRIPTOR, direction, orientation, true> {
static void interpolateVector(T velDeriv[DESCRIPTOR::d],
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY)
{
using namespace fd;
T u0[DESCRIPTOR::d], u1[DESCRIPTOR::d], u2[DESCRIPTOR::d];
blockLattice.get(iX,iY).computeU(u0);
blockLattice.get (
iX+(direction==0 ? (-orientation):0),
iY+(direction==1 ? (-orientation):0) ).computeU(u1);
blockLattice.get (
iX+(direction==0 ? (-2*orientation):0),
iY+(direction==1 ? (-2*orientation):0) ).computeU(u2);
for (int iD=0; iD<DESCRIPTOR::d; ++iD) {
velDeriv[iD] = -orientation * boundaryGradient(u0[iD], u1[iD], u2[iD]);
}
}
static void interpolateScalar(T& rhoDeriv,
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY)
{
using namespace fd;
T rho0 = blockLattice.get(iX,iY).computeRho();
T rho1 = blockLattice.get (
iX+(direction==0 ? (-orientation):0),
iY+(direction==1 ? (-orientation):0) ).computeRho();
T rho2 = blockLattice.get (
iX+(direction==0 ? (-2*orientation):0),
iY+(direction==1 ? (-2*orientation):0) ).computeRho();
rhoDeriv = -orientation * boundaryGradient(rho0, rho1, rho2);
}
};
// Implementation for orthogonal==false; i.e. the derivative is aligned
// with the boundary.
template<typename T, typename DESCRIPTOR,
int direction, int orientation>
struct DirectedGradients2D<T, DESCRIPTOR, direction, orientation, false> {
static void interpolateVector(T velDeriv[DESCRIPTOR::d],
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY)
{
using namespace fd;
T u_p1[DESCRIPTOR::d], u_m1[DESCRIPTOR::d];
int deriveDirection = 1-direction;
blockLattice.get (
iX+(deriveDirection==0 ? 1:0),
iY+(deriveDirection==1 ? 1:0) ).computeU(u_p1);
blockLattice.get (
iX+(deriveDirection==0 ? (-1):0),
iY+(deriveDirection==1 ? (-1):0) ).computeU(u_m1);
for (int iD=0; iD<DESCRIPTOR::d; ++iD) {
velDeriv[iD] = fd::centralGradient(u_p1[iD],u_m1[iD]);
}
}
static void interpolateScalar(T& rhoDeriv,
BlockLattice2D<T,DESCRIPTOR> const& blockLattice,
int iX, int iY)
{
using namespace fd;
int deriveDirection = 1-direction;
T rho_p1 = blockLattice.get (
iX+(deriveDirection==0 ? 1:0),
iY+(deriveDirection==1 ? 1:0) ).computeRho();
T rho_m1 = blockLattice.get (
iX+(deriveDirection==0 ? (-1):0),
iY+(deriveDirection==1 ? (-1):0) ).computeRho();
rhoDeriv = centralGradient(rho_p1, rho_m1);
}
};
} // namespace fd
} // namespace olb
#endif
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