olb::ChemicalPotentialCoupling2D Struct Reference

#include <freeEnergyCoupling2D.h>

Collaboration diagram for olb::ChemicalPotentialCoupling2D:

Classes
struct	ALPHA
struct	KAPPA1
struct	KAPPA2
struct	KAPPA3

Public Types
using	parameters = meta::list<ALPHA, KAPPA1, KAPPA2, KAPPA3>

Public Member Functions
template<typename CELLS , typename PARAMETERS >
void	apply (CELLS &cells, PARAMETERS &parameters) any_platform

Static Public Attributes
static constexpr OperatorScope	scope = OperatorScope::PerCellWithParameters

Detailed Description

Definition at line 29 of file freeEnergyCoupling2D.h.

Member Typedef Documentation

parameters

using olb::ChemicalPotentialCoupling2D::parameters = meta::list<ALPHA, KAPPA1, KAPPA2, KAPPA3>

Definition at line 39 of file freeEnergyCoupling2D.h.

Member Function Documentation

apply()

template<typename CELLS , typename PARAMETERS >

void olb::ChemicalPotentialCoupling2D::apply ( CELLS & cells, PARAMETERS & parameters )

inline

Definition at line 43 of file freeEnergyCoupling2D.h.

                                                                {
 
    using V = typename CELLS::template value_t<names::A>::value_t;
    using DESCRIPTOR = typename CELLS::template value_t<names::A>::descriptor_t;
 
    // Get the cell of the first lattice
    auto& cellA = cells.template get<names::A>();
 
    // Get the cell of the second lattice
    auto& cellB = cells.template get<names::B>();
 
    V rhoA = cellA.computeRho();
    V rhoB = cellB.computeRho();
 
    V densitySum = rhoA + rhoB;
    V densityDifference = rhoA - rhoB;
 
    V kappa1 = parameters.template get<KAPPA1>();
    V kappa2 = parameters.template get<KAPPA2>();
 
    V term1 = 0.125 * kappa1 * (densitySum)
                  * (densitySum-1.) * (densitySum-2.);
 
    V term2 = 0.125 * kappa2 * (densityDifference)
                  * (densityDifference-1.) * (densityDifference-2.);
 
    V laplaceRho1 = -12.0 * rhoA;
    V laplaceRho2 = -12.0 * rhoB;
    V laplaceRho3 = 0.; // Only used in case of three fluids / lattices
 
    auto alpha = parameters.template get<ALPHA>();
 
    // Three fluids / lattices involved: A, B, and C
    if constexpr (CELLS::map_t::keys_t::template contains<names::C>()){
      // Cell of the third lattice:
      auto& cellC = cells.template get<names::C>();
 
      V rhoC = cellC.computeRho();
 
      densitySum -= rhoC;
      densityDifference -= rhoC;
 
      V kappa3 = parameters.template get<KAPPA3>();
      V term3 = kappa3 * rhoC * (rhoC - 1.) * (2. * rhoC - 1.);
 
      laplaceRho3 = -12.0 * rhoC;
 
      /*
      * The neighbours of the currently looked at cell
      * (i.e. cell 0) are ordered as following:
      *
      *    1 - 8 - 7
      *    |   |   |
      *    2 - 0 - 6
      *    |   |   |
      *    3 - 4 - 5
      */
      for(int iPop=1; iPop<DESCRIPTOR::q; iPop++) {
 
        auto nextCellA = cellA.neighbor(descriptors::c<DESCRIPTOR>(iPop));
        auto nextCellB = cellB.neighbor(descriptors::c<DESCRIPTOR>(iPop));
        auto nextCellC = cellC.neighbor(descriptors::c<DESCRIPTOR>(iPop));
 
        V rhoA = nextCellA.computeRho();
        V rhoB = nextCellB.computeRho();
        V rhoC = nextCellC.computeRho();
 
        if(iPop % 2 == 0) {
          laplaceRho1 += (2. * rhoA);
          laplaceRho2 += (2. * rhoB);
          laplaceRho3 += (2. * rhoC);
        } else {
          laplaceRho1 += rhoA;
          laplaceRho2 += rhoB;
          laplaceRho3 += rhoC;
        }
      }
 
      laplaceRho1 *= 0.25;
      laplaceRho2 *= 0.25;
      laplaceRho3 *= 0.25;
 
      cellC.template setField<descriptors::CHEM_POTENTIAL>( - term1 - term2 + term3
            + 0.25*alpha*alpha*( (kappa2 + kappa1) * laplaceRho1
                                 -(kappa2 - kappa1) * laplaceRho2
                                 -(kappa2 + kappa1 + 4.*kappa3) * laplaceRho3 ));
 
 
    } else { // Only 2 fluids / lattices involved: A and B
 
      for(int iPop=1; iPop<DESCRIPTOR::q; iPop++) {
 
        auto nextCellA = cellA.neighbor(descriptors::c<DESCRIPTOR>(iPop));
        auto nextCellB = cellB.neighbor(descriptors::c<DESCRIPTOR>(iPop));
 
        V rhoA = nextCellA.computeRho();
        V rhoB = nextCellB.computeRho();
 
        if(iPop % 2 == 0) {
          laplaceRho1 += (2. * rhoA);
          laplaceRho2 += (2. * rhoB);
        } else {
          laplaceRho1 += rhoA;
          laplaceRho2 += rhoB;
        }
      }
 
      laplaceRho1 *= 0.25;
      laplaceRho2 *= 0.25;
 
    }
 
    cellA.template setField<descriptors::CHEM_POTENTIAL>(term1 + term2
            + 0.25*alpha*alpha*( (kappa2 - kappa1) * laplaceRho2
                                 +(kappa2 + kappa1) * (laplaceRho3 - laplaceRho1) ));
 
    cellB.template setField<descriptors::CHEM_POTENTIAL>(term1 - term2
            + 0.25*alpha*alpha*( (kappa2 - kappa1) * (laplaceRho1 - laplaceRho3)
                                 -(kappa2 + kappa1) * laplaceRho2 ));
 
  }

Member Data Documentation

scope

constexpr OperatorScope olb::ChemicalPotentialCoupling2D::scope = OperatorScope::PerCellWithParameters

staticconstexpr

Definition at line 32 of file freeEnergyCoupling2D.h.

---

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

• src/dynamics/freeEnergyCoupling2D.h