Implementation of Zou-He boundary condition following the paper from Zou and He. More...

#include <zouHeDynamics.h>

Inheritance diagram for olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >:

Collaboration diagram for olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >:

Public Types
using	MomentaF = typename MOMENTA::template type<DESCRIPTOR>

using	parameters = typename CORRECTED_DYNAMICS::parameters

template<typename M >
using	exchange_momenta = ZouHeDynamics<T,DESCRIPTOR,DYNAMICS,M,direction,orientation>

Public Types inherited from olb::dynamics::CustomCollision< T, DESCRIPTOR, MOMENTA >
using	value_t = T

using	descriptor_t = DESCRIPTOR

using	MomentaF = typename MOMENTA::template type<DESCRIPTOR>

Public Types inherited from olb::Dynamics< T, DESCRIPTOR >
using	value_t = T

using	descriptor_t = DESCRIPTOR

Public Member Functions
std::type_index	id () override
	Expose unique type-identifier for RTTI.

AbstractParameters< T, DESCRIPTOR > &	getParameters (BlockLattice< T, DESCRIPTOR > &block) override
	Parameters access for legacy post processors.

template<typename CELL , typename PARAMETERS , typename V = typename CELL::value_t>
CellStatistic< V >	apply (CELL &cell, PARAMETERS &parameters) any_platform

T	computeEquilibrium (int iPop, T rho, const T u[DESCRIPTOR::d]) const override any_platform
	Return iPop equilibrium for given first and second momenta.

std::string	getName () const override
	Return human-readable name.

Public Member Functions inherited from olb::dynamics::CustomCollision< T, DESCRIPTOR, MOMENTA >
void	initialize (Cell< T, DESCRIPTOR > &cell) override
	Initialize dynamics-specific data for cell.

T	computeRho (ConstCell< T, DESCRIPTOR > &cell) const override
	Compute particle density.

void	computeU (ConstCell< T, DESCRIPTOR > &cell, T u[DESCRIPTOR::d]) const override
	Compute fluid velocity.

void	computeJ (ConstCell< T, DESCRIPTOR > &cell, T j[DESCRIPTOR::d]) const override
	Compute fluid momentum.

void	computeStress (ConstCell< T, DESCRIPTOR > &cell, T rho, const T u[DESCRIPTOR::d], T pi[util::TensorVal< DESCRIPTOR >::n]) const override
	Compute stress tensor.

void	computeRhoU (ConstCell< T, DESCRIPTOR > &cell, T &rho, T u[DESCRIPTOR::d]) const override
	Compute fluid velocity and particle density.

void	computeAllMomenta (ConstCell< T, DESCRIPTOR > &cell, T &rho, T u[DESCRIPTOR::d], T pi[util::TensorVal< DESCRIPTOR >::n]) const override
	Compute all momenta up to second order.

void	defineRho (Cell< T, DESCRIPTOR > &cell, T rho) override
	Set particle density.

void	defineU (Cell< T, DESCRIPTOR > &cell, const T u[DESCRIPTOR::d]) override
	Set fluid velocity.

void	defineRhoU (Cell< T, DESCRIPTOR > &cell, T rho, const T u[DESCRIPTOR::d]) override
	Define fluid velocity and particle density.

void	defineAllMomenta (Cell< T, DESCRIPTOR > &cell, T rho, const T u[DESCRIPTOR::d], const T pi[util::TensorVal< DESCRIPTOR >::n]) override
	Define all momenta up to second order.

void	inverseShiftRhoU (ConstCell< T, DESCRIPTOR > &cell, T &rho, T u[DESCRIPTOR::d]) const override
	Calculate population momenta s.t. the physical momenta are reproduced by the computeRhoU.

Public Member Functions inherited from olb::Dynamics< T, DESCRIPTOR >
virtual	~Dynamics () any_platform

virtual CellStatistic< T >	collide (Cell< T, DESCRIPTOR > &cell)
	Perform purely-local collision step on Cell interface (legacy, to be deprecated)

void	iniEquilibrium (Cell< T, DESCRIPTOR > &cell, T rho, const T u[DESCRIPTOR::d])
	Initialize to equilibrium distribution.

void	iniRegularized (Cell< T, DESCRIPTOR > &cell, T rho, const T u[DESCRIPTOR::d], const T pi[util::TensorVal< DESCRIPTOR >::n])
	Initialize cell to equilibrium and non-equilibrum part.

Detailed Description

template<typename T, typename DESCRIPTOR, typename DYNAMICS, typename MOMENTA, int direction, int orientation>
class olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >

Implementation of Zou-He boundary condition following the paper from Zou and He.

This implementation is lattice independent. The implementation follow the idea proposed int the paper Qisu Zou, Xiaoyi He, "On pressure and velocity boundary conditions for the lattice Boltzmann BGK model", Phys. Fluids , (1997), Volume 9, Issue 6, pp. 1591-1598

Definition at line 40 of file zouHeDynamics.h.

Member Typedef Documentation

◆ exchange_momenta

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

template<typename M >

using olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::exchange_momenta = ZouHeDynamics<T,DESCRIPTOR,DYNAMICS,M,direction,orientation>

Definition at line 51 of file zouHeDynamics.h.

◆ MomentaF

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

using olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::MomentaF = typename MOMENTA::template type<DESCRIPTOR>

Definition at line 46 of file zouHeDynamics.h.

◆ parameters

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

using olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::parameters = typename CORRECTED_DYNAMICS::parameters

Definition at line 48 of file zouHeDynamics.h.

Member Function Documentation

◆ apply()

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

template<typename CELL , typename PARAMETERS , typename V = typename CELL::value_t>

CellStatistic< V > olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::apply	(	CELL &	cell,
		PARAMETERS &	parameters )

inline

Definition at line 62 of file zouHeDynamics.h.

                                                                          {
    // 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)
    constexpr auto missingIndexesTmp = util::subIndexOutgoing<DESCRIPTOR,direction,orientation>();
    std::vector<int> missingIndexes(missingIndexesTmp.cbegin(), missingIndexesTmp.cend());
 
    // 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 < DESCRIPTOR::d; ++iDim) {
        numOfNonNullComp += util::abs(descriptors::c<DESCRIPTOR>(missingIndexes[iPop],iDim));
      }
 
      if (numOfNonNullComp == 1) {
        missingDiagonalIndexes.erase(missingDiagonalIndexes.begin()+iPop);
        break;
      }
    }
 
    V rho, u[DESCRIPTOR::d];
    V falseRho, falseU[DESCRIPTOR::d];
    MomentaF().computeRhoU(cell, rho, u);
    V uSqr = util::normSqr<V,DESCRIPTOR::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[descriptors::opposite<DESCRIPTOR>(missingIndexes[iPop])]
        - computeEquilibrium(descriptors::opposite<DESCRIPTOR>(missingIndexes[iPop]), rho, u)
        + computeEquilibrium(missingIndexes[iPop], rho, u);
    }
 
    // 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.
    lbm<DESCRIPTOR>::computeRhoU(cell,falseRho,falseU);
 
    V diff[DESCRIPTOR::d] {};
    for (int iDim = 0; iDim < DESCRIPTOR::d; ++iDim) {
      diff[iDim] = (rho*u[iDim] - falseRho*falseU[iDim])/ V(missingDiagonalIndexes.size());
    }
 
    for (unsigned iPop = 0; iPop < missingDiagonalIndexes.size(); ++iPop) {
      for (int iDim = 1; iDim < DESCRIPTOR::d; ++iDim) {
        cell[missingDiagonalIndexes[iPop]] +=
          descriptors::c<DESCRIPTOR>(missingDiagonalIndexes[iPop],(direction+iDim)%DESCRIPTOR::d) * diff[(direction+iDim)%DESCRIPTOR::d];
      }
    }
 
    typename CORRECTED_DYNAMICS::CollisionO().apply(cell, parameters);
 
    return {rho, uSqr};
  }

References olb::util::abs(), olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::computeEquilibrium(), and olb::lbm< DESCRIPTOR >::computeRhoU().

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◆ computeEquilibrium()

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

T olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::computeEquilibrium	(	int	iPop,
		T	rho,
		const T	u[DESCRIPTOR::d] ) const

inlineoverridevirtual

Return iPop equilibrium for given first and second momenta.

Implements olb::Dynamics< T, DESCRIPTOR >.

Definition at line 124 of file zouHeDynamics.h.

                                                                                            {
    return typename CORRECTED_DYNAMICS::EquilibriumF().compute(iPop, rho, u);
  };

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◆ getName()

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

std::string olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::getName ( ) const

inlineoverridevirtual

Return human-readable name.

Reimplemented from olb::Dynamics< T, DESCRIPTOR >.

Definition at line 128 of file zouHeDynamics.h.

                                     {
    return "ZouHeDynamics<" + CORRECTED_DYNAMICS().getName() + ">";
  };

◆ getParameters()

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

AbstractParameters< T, DESCRIPTOR > & olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::getParameters ( BlockLattice< T, DESCRIPTOR > & block )

inlineoverridevirtual

Parameters access for legacy post processors.

Implements olb::Dynamics< T, DESCRIPTOR >.

Definition at line 57 of file zouHeDynamics.h.

                                                                                              {
    return block.template getData<OperatorParameters<ZouHeDynamics>>();
  }

◆ id()

template<typename T , typename DESCRIPTOR , typename DYNAMICS , typename MOMENTA , int direction, int orientation>

std::type_index olb::ZouHeDynamics< T, DESCRIPTOR, DYNAMICS, MOMENTA, direction, orientation >::id ( )

inlineoverridevirtual

Expose unique type-identifier for RTTI.

Implements olb::Dynamics< T, DESCRIPTOR >.

Definition at line 53 of file zouHeDynamics.h.

                              {
    return typeid(ZouHeDynamics);
  }

The documentation for this class was generated from the following file:

src/boundary/zouHeDynamics.h

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ exchange_momenta

◆ MomentaF

◆ parameters

Member Function Documentation

◆ apply()

◆ computeEquilibrium()

◆ getName()

◆ getParameters()

◆ id()