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/* This file is part of the OpenLB library
*
* Copyright (C) 2017 Davide Dapelo
* 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.
*/
/** \file
* Smagorinsky BGK Dynamics for porous -- generic implementation.
*/
#ifndef SMAGORINSKY_POROUS_PARTICLE_BGK_DYNAMICS_HH
#define SMAGORINSKY_POROUS_PARTICLE_BGK_DYNAMICS_HH
#include "dynamics/porousBGKdynamics.hh"
namespace olb {
////////////////////// Class PorousParticleBGKdynamics //////////////////////////
template<typename T, typename DESCRIPTOR>
SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::SmagorinskyPorousParticleBGKdynamics(T omega_,
Momenta<T,DESCRIPTOR>& momenta_, T smagoConst_, T dx_, T dt_ )
: PorousParticleBGKdynamics<T,DESCRIPTOR>(omega_,momenta_), smagoConst(smagoConst_),
preFactor(computePreFactor(omega_,smagoConst_) )
{ }
template<typename T, typename DESCRIPTOR>
void SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::collide (
Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics )
{
T rho, u[DESCRIPTOR::d], pi[util::TensorVal<DESCRIPTOR >::n];
this->_momenta.computeAllMomenta(cell, rho, u, pi);
/*
T* porosity = cell.template getFieldPointer<descriptors::POROSITY>();
for (int i=0; i<DESCRIPTOR::d; i++) {
u[i] *= porosity[0];
}
*/
T* velDenominator = cell.template getFieldPointer<descriptors::VELOCITY_DENOMINATOR>();
T* velNumerator = cell.template getFieldPointer<descriptors::VELOCITY_NUMERATOR>();
T* porosity = cell.template getFieldPointer<descriptors::POROSITY>();
if (*velDenominator > std::numeric_limits<T>::epsilon()) {
*porosity = 1.-*porosity; // 1-prod(1-smoothInd)
for (int i=0; i < DESCRIPTOR::d; i++) {
u[i] += *porosity * (*(velNumerator+i) / *velDenominator - u[i]);
}
}
T newOmega = computeOmega(this->getOmega(), preFactor, rho, pi);
T uSqr = lbHelpers<T,DESCRIPTOR>::bgkCollision(cell, rho, u, newOmega);
statistics.incrementStats(rho, uSqr);
cell.template defineField<descriptors::POROSITY>(1.0);
cell.template defineField<descriptors::VELOCITY_DENOMINATOR>(0.0);
cell.template defineField<descriptors::VELOCITY_NUMERATOR>(0.0);
}
template<typename T, typename DESCRIPTOR>
void SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::setOmega(T omega_)
{
PorousParticleBGKdynamics<T,DESCRIPTOR>::setOmega(omega_);
preFactor = computePreFactor(omega_, smagoConst);
}
template<typename T, typename DESCRIPTOR>
T SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::getSmagorinskyOmega(Cell<T,DESCRIPTOR>& cell )
{
T rho, uTemp[DESCRIPTOR::d], pi[util::TensorVal<DESCRIPTOR >::n];
this->_momenta.computeAllMomenta(cell, rho, uTemp, pi);
T newOmega = computeOmega(this->getOmega(), preFactor, rho, pi);
return newOmega;
}
template<typename T, typename DESCRIPTOR>
T SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::computePreFactor(T omega_, T smagoConst_)
{
return (T)smagoConst_*smagoConst_*descriptors::invCs2<T,DESCRIPTOR>()*descriptors::invCs2<T,DESCRIPTOR>()*2*sqrt(2);
}
template<typename T, typename DESCRIPTOR>
T SmagorinskyPorousParticleBGKdynamics<T,DESCRIPTOR>::computeOmega(T omega0, T preFactor_, T rho,
T pi[util::TensorVal<DESCRIPTOR >::n] )
{
T PiNeqNormSqr = pi[0]*pi[0] + 2.0*pi[1]*pi[1] + pi[2]*pi[2];
if (util::TensorVal<DESCRIPTOR >::n == 6) {
PiNeqNormSqr += pi[2]*pi[2] + pi[3]*pi[3] + 2*pi[4]*pi[4] +pi[5]*pi[5];
}
T PiNeqNorm = sqrt(PiNeqNormSqr);
/// Molecular realaxation time
T tau_mol = 1. /omega0;
/// Turbulent realaxation time
T tau_turb = 0.5*(sqrt(tau_mol*tau_mol + preFactor_/rho*PiNeqNorm) - tau_mol);
/// Effective realaxation time
tau_eff = tau_mol+tau_turb;
T omega_new= 1./tau_eff;
return omega_new;
}
} // olb
#endif
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