olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA > Class Template Reference

Implementation of the entropic collision step. More...

#include <entropicDynamics.h>

Inheritance diagram for olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >:

Collaboration diagram for olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >:

Public Types
template<typename M >
using	exchange_momenta = EntropicDynamics<T,DESCRIPTOR,M>
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
	EntropicDynamics (T omega_)
	Constructor.
T	computeEquilibrium (int iPop, T rho, const T u[DESCRIPTOR::d], T uSqr) const override
	Compute equilibrium distribution function.
CellStatistic< T >	collide (Cell< T, DESCRIPTOR > &cell) override
	Collision step.
T	getOmega () const
	Get local relaxation parameter of the dynamics.
void	setOmega (T omega_)
	Set local relaxation parameter of the dynamics.
Public Member Functions inherited from olb::legacy::BasicDynamics< T, DESCRIPTOR, MOMENTA >
T	computeEquilibrium (int iPop, T rho, const T u[DESCRIPTOR::d]) const override
	Return iPop equilibrium for given first and second momenta.
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.
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 std::string	getName () const
	Return human-readable name.
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 MOMENTA = momenta::BulkTuple>
class olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >

Implementation of the entropic collision step.

Definition at line 88 of file entropicDynamics.h.

Member Typedef Documentation

exchange_momenta

template<typename T , typename DESCRIPTOR , typename MOMENTA = momenta::BulkTuple>

template<typename M >

using olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::exchange_momenta = EntropicDynamics<T,DESCRIPTOR,M>

Definition at line 91 of file entropicDynamics.h.

Constructor & Destructor Documentation

EntropicDynamics()

template<typename T , typename DESCRIPTOR , typename MOMENTA >

olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::EntropicDynamics

(

T

omega_

)

Constructor.

Parameters

omega_	relaxation parameter, related to the dynamic viscosity
momenta_	a Momenta object to know how to compute velocity momenta

Definition at line 156 of file entropicDynamics.hh.

  : legacy::BasicDynamics<T,DESCRIPTOR,MOMENTA>(),
    omega(omega_)
{
  this->getName() = "EntropicDynamics";
}

References olb::Dynamics< T, DESCRIPTOR >::getName().

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Member Function Documentation

collide()

template<typename T , typename DESCRIPTOR , typename MOMENTA >

CellStatistic< T > olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::collide ( Cell< T, DESCRIPTOR > & cell )

overridevirtual

Collision step.

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

Definition at line 170 of file entropicDynamics.hh.

{
  typedef DESCRIPTOR L;
  typedef entropicLbHelpers<T,DESCRIPTOR> eLbH;
 
  T rho, u[DESCRIPTOR::d];
  MOMENTA().computeRhoU(cell, rho, u);
  T uSqr = util::normSqr<T,L::d>(u);
 
  T f[L::q], fEq[L::q], fNeq[L::q];
  for (int iPop = 0; iPop < L::q; ++iPop) {
    fEq[iPop]  = eLbH::equilibrium(iPop,rho,u);
    fNeq[iPop] = cell[iPop] - fEq[iPop];
    f[iPop]    = cell[iPop] + descriptors::t<T,L>(iPop);
    fEq[iPop] += descriptors::t<T,L>(iPop);
  }
  //==============================================================================//
  //============= Evaluation of alpha using a Newton Raphson algorithm ===========//
  //==============================================================================//
 
  T alpha = 2.0;
  bool converged = getAlpha(alpha,f,fNeq);
  if (!converged) {
    std::cout << "Newton-Raphson failed to converge.\n";
    exit(1);
  }
 
  OLB_ASSERT(converged,"Entropy growth failed to converge!");
 
  T omegaTot = omega / 2.0 * alpha;
  for (int iPop=0; iPop < DESCRIPTOR::q; ++iPop) {
    cell[iPop] *= (T)1-omegaTot;
    cell[iPop] += omegaTot * (fEq[iPop]-descriptors::t<T,L>(iPop));
  }
 
  //statistics.incrementStats(rho, uSqr);
}

References OLB_ASSERT.

computeEquilibrium()

template<typename T , typename DESCRIPTOR , typename MOMENTA >

T olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::computeEquilibrium ( int iPop, T rho, const T u[DESCRIPTOR::d], T uSqr ) const

override

Compute equilibrium distribution function.

Definition at line 164 of file entropicDynamics.hh.

{
  return entropicLbHelpers<T,DESCRIPTOR>::equilibrium(iPop,rho,u);
}

References olb::entropicLbHelpers< T, DESCRIPTOR >::equilibrium().

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getOmega()

template<typename T , typename DESCRIPTOR , typename MOMENTA >

T olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::getOmega

(

)

const

Get local relaxation parameter of the dynamics.

Definition at line 210 of file entropicDynamics.hh.

{
  return omega;
}

setOmega()

template<typename T , typename DESCRIPTOR , typename MOMENTA >

void olb::EntropicDynamics< T, DESCRIPTOR, MOMENTA >::setOmega

(

T

omega_

)

Set local relaxation parameter of the dynamics.

Definition at line 216 of file entropicDynamics.hh.

{
  omega = omega_;
}

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

• src/dynamics/entropicDynamics.h
• src/dynamics/entropicDynamics.hh