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/* This file is part of the OpenLB library
*
* Copyright (C) 2012 Lukas Baron, Mathias J. Krause, 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.
*/
/** \file
* BGK Dynamics for porous media -- header file.
*/
#ifndef POROUS_BGK_DYNAMICS_H
#define POROUS_BGK_DYNAMICS_H
#include "dynamics/dynamics.h"
#include "core/cell.h"
namespace olb {
/// Implementation of the BGK collision step for a porosity model
template<typename T, typename DESCRIPTOR>
class PorousBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
PorousBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// Collision step
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
};
/// Implementation of the BGK collision step for a porosity model enabling
/// drag computation
template<typename T, typename DESCRIPTOR>
class ExtendedPorousBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
ExtendedPorousBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
};
/// Implementation of the BGK collision step for subgridscale particles
template<typename T, typename DESCRIPTOR>
class SubgridParticleBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
SubgridParticleBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
T _fieldTmp[4];
};
/* Implementation of the BGK collision for moving porous media (HLBM approach).
* As this scheme requires additionla data stored in an external field,
* it is meant to be used along with a PorousParticle descriptor.
* \param omega Lattice relaxation frequency
* \param momenta A standard object for the momenta computation
*/
template<typename T, typename DESCRIPTOR, bool isStatic=false>
class PorousParticleBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
PorousParticleBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
/// This structure is used to emulate a "static if" to switch between static and
/// dynamic case. It can be replaced by a "constexpr if" when switching to C++17
/// standard.
template<bool isStaticStruct, bool dummy = true> struct effectiveVelocity {
static void calculate(T* pExternal, T* pVelocity);
};
};
/// Implementation of the HBGK collision step for a porosity model enabling
/// drag computation for many particles
/// including the Krause turbulence modell
template<typename T, typename DESCRIPTOR>
class KrauseHBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
KrauseHBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_, T smagoConst_, T dx_ = 1, T dt_ = 1);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
/// Computes a constant prefactor in order to speed up the computation
T computePreFactor(T omega_, T smagoConst_);
/// Computes the local smagorinsky relaxation parameter
void computeOmega(T omega0_, Cell<T,DESCRIPTOR>& cell, T preFactor_, T rho_,
T u[DESCRIPTOR::d],
T newOmega[DESCRIPTOR::q] );
private:
T omega; ///< relaxation parameter
/// effective collision time based upon Smagorisnky approach
T tau_eff;
/// Smagorinsky constant
T smagoConst;
/// Precomputed constant which speeeds up the computation
T preFactor;
T dx;
T dt;
T _fieldTmp[4];
};
/// Implementation of the BGK collision step for a porosity model enabling
/// drag computation
template<typename T, typename DESCRIPTOR>
class ParticlePorousBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
ParticlePorousBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
};
/// Implementation of the BGK collision step for a small particles enabling
/// two way coupling
template<typename T, typename DESCRIPTOR>
class SmallParticleBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
SmallParticleBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_);
/// extended Collision step, computes local drag in a given direction
virtual void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_);
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
};
enum Mode {M2, M3};
/// Implementation of the Partially Saturated Method (PSM),
/// see Krüger, Timm, et al. The Lattice Boltzmann Method. Springer, 2017. (p.447-451)
template<typename T, typename DESCRIPTOR>
class PSMBGKdynamics : public BGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
PSMBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_, int mode_=0);
/// Compute fluid velocity on the cell.
void computeU (
Cell<T,DESCRIPTOR> const& cell,
T u[DESCRIPTOR::d] ) const override;
/// Compute fluid velocity and particle density on the cell.
void computeRhoU (
Cell<T,DESCRIPTOR> const& cell,
T& rho, T u[DESCRIPTOR::d]) const override;
/// Collision step
void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_) override;
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
T paramA; /// speed up parameter
Mode mode;
};
/// Implementation of the Partially Saturated Method (PSM),
/// see Krüger, Timm, et al. The Lattice Boltzmann Method. Springer, 2017. (p.447-451)
template<typename T, typename DESCRIPTOR>
class ForcedPSMBGKdynamics : public ForcedBGKdynamics<T,DESCRIPTOR> {
public:
/// Constructor
ForcedPSMBGKdynamics(T omega_, Momenta<T,DESCRIPTOR>& momenta_, int mode_=0);
/// Compute fluid velocity on the cell.
void computeU (
Cell<T,DESCRIPTOR> const& cell,
T u[DESCRIPTOR::d] ) const override;
/// Compute fluid velocity and particle density on the cell.
void computeRhoU (
Cell<T,DESCRIPTOR> const& cell,
T& rho, T u[DESCRIPTOR::d]) const override;
/// Collision step
void collide(Cell<T,DESCRIPTOR>& cell,
LatticeStatistics<T>& statistics_) override;
/// get relaxation parameter
T getOmega() const;
/// set relaxation parameter
void setOmega(T omega_);
private:
T omega; ///< relaxation parameter
T paramA; /// speed up parameter
Mode mode;
};
} // olb
#endif
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