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/* This file is part of the OpenLB library
*
* Copyright (C) 2006,2007 Orestis Malaspinas and 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 ZOU_HE_DYNAMICS_HH
#define ZOU_HE_DYNAMICS_HH
#include "zouHeDynamics.h"
#include "dynamics/latticeDescriptors.h"
#include "core/util.h"
#include "dynamics/lbHelpers.h"
#include <cmath>
namespace olb {
template<typename T, typename DESCRIPTOR, typename Dynamics, int direction, int orientation>
ZouHeDynamics<T,DESCRIPTOR,Dynamics,direction,orientation>::ZouHeDynamics (
T omega_, Momenta<T,DESCRIPTOR>& momenta_ )
: BasicDynamics<T,DESCRIPTOR>(momenta_),
boundaryDynamics(omega_, momenta_)
{ }
template<typename T, typename DESCRIPTOR, typename Dynamics, int direction, int orientation>
T ZouHeDynamics<T,DESCRIPTOR, Dynamics, direction, orientation>::
computeEquilibrium(int iPop, T rho, const T u[DESCRIPTOR::d], T uSqr) const
{
return boundaryDynamics.computeEquilibrium(iPop, rho, u, uSqr);
}
template<typename T, typename DESCRIPTOR, typename Dynamics, int direction, int orientation>
void ZouHeDynamics<T,DESCRIPTOR,Dynamics,direction,orientation>::collide (
Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics )
{
typedef lbHelpers<T,DESCRIPTOR> lbH;
typedef DESCRIPTOR L;
// Along all the commented parts of this code there will be an example based
// on the situation where the wall's normal vector if (0,1) and the
// numerotation of the velocites are done according to the D2Q9
// lattice of the OpenLB library.
// Find all the missing populations
// (directions 3,4,5)
std::vector<int> missingIndexes = util::subIndexOutgoing<L,direction,orientation>();
// Will contain the missing poputations that are not normal to the wall.
// (directions 3,5)
std::vector<int> missingDiagonalIndexes = missingIndexes;
for (unsigned iPop = 0; iPop < missingIndexes.size(); ++iPop) {
int numOfNonNullComp = 0;
for (int iDim = 0; iDim < L::d; ++iDim) {
numOfNonNullComp += abs(descriptors::c<L>(missingIndexes[iPop],iDim));
}
if (numOfNonNullComp == 1) {
missingDiagonalIndexes.erase(missingDiagonalIndexes.begin()+iPop);
break;
}
}
T rho, u[L::d];
T falseRho, falseU[L::d];
this->_momenta.computeRhoU(cell, rho, u);
T uSqr = util::normSqr<T,L::d>(u);
// The unknown non equilibrium populations are bounced back
// (f[3] = feq[3] + fneq[7], f[4] = feq[4] + fneq[8],
// f[5] = feq[5] + fneq[1])
for (unsigned iPop = 0; iPop < missingIndexes.size(); ++iPop) {
cell[missingIndexes[iPop]] = cell[util::opposite<L>(missingIndexes[iPop])]
- computeEquilibrium(util::opposite<L>(missingIndexes[iPop]), rho, u, uSqr)
+ computeEquilibrium(missingIndexes[iPop], rho, u, uSqr);
}
// We recompute rho and u in order to have the new momentum and density. Since
// the momentum is not conserved from this scheme, we will corect it. By adding
// a contribution to the missingDiagonalVelocities.
lbH::computeRhoU(cell,falseRho,falseU);
T diff[L::d];
for (int iDim = 0; iDim < L::d; ++iDim) {
diff[iDim] = (rho*u[iDim] - falseRho*falseU[iDim])/ (T)missingDiagonalIndexes.size();
}
for (unsigned iPop = 0; iPop < missingDiagonalIndexes.size(); ++iPop) {
for (int iDim = 1; iDim < L::d; ++iDim) {
cell[missingDiagonalIndexes[iPop]] +=
descriptors::c<L>(missingDiagonalIndexes[iPop],(direction+iDim)%L::d) * diff[(direction+iDim)%L::d];
}
}
boundaryDynamics.collide(cell, statistics);
statistics.incrementStats(rho, uSqr);
}
template<typename T, typename DESCRIPTOR, typename Dynamics, int direction, int orientation>
T ZouHeDynamics<T,DESCRIPTOR,Dynamics,direction,orientation>::getOmega() const
{
return boundaryDynamics.getOmega();
}
template<typename T, typename DESCRIPTOR, typename Dynamics, int direction, int orientation>
void ZouHeDynamics<T,DESCRIPTOR,Dynamics,direction,orientation>::setOmega(T omega_)
{
boundaryDynamics.setOmega(omega_);
}
} // namespace olb
#endif
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