olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM > Struct Template Reference

#include <collisionKBC.h>

Collaboration diagram for olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM >:

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

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

Detailed Description

template<typename DESCRIPTOR, typename MOMENTA, typename EQUILIBRIUM>
struct olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM >

Definition at line 43 of file collisionKBC.h.

Member Typedef Documentation

EquilibriumF

template<typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

using olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM >::EquilibriumF = typename EQUILIBRIUM::template type<DESCRIPTOR,MOMENTA>

Definition at line 48 of file collisionKBC.h.

MomentaF

template<typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

using olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM >::MomentaF = typename MOMENTA::template type<DESCRIPTOR>

Definition at line 49 of file collisionKBC.h.

Member Function Documentation

apply()

template<typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

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

CellStatistic< V > olb::collision::KBC::type< DESCRIPTOR, MOMENTA, EQUILIBRIUM >::apply ( CELL & cell, PARAMETERS & parameters )

inline

Definition at line 52 of file collisionKBC.h.

                                                                            {
 
      V fEq[DESCRIPTOR::q] { };
      const auto statistic = EquilibriumF().compute(cell, parameters, fEq);
      V rho, u[DESCRIPTOR::d];
      MomentaF().computeRhoU(cell, rho, u);
 
      const V omega = parameters.template get<descriptors::OMEGA>();
 
      V df[DESCRIPTOR::q];
      for (int iPop=0; iPop < DESCRIPTOR::q; ++iPop) {
        df[iPop]   = cell[iPop] -  fEq[iPop];
        fEq[iPop] += descriptors::t<V,DESCRIPTOR>(iPop);
      }
 
      V M200 = 0 , M011 = 0;
      V M002 = 0, M110 = 0;
      V M020 = 0, M101 = 0;
      for (int iPop = 0; iPop < DESCRIPTOR::q; ++iPop) {
        V c0 = descriptors::c<DESCRIPTOR::d, DESCRIPTOR::q>(iPop, 0);
        V c1 = descriptors::c<DESCRIPTOR::d, DESCRIPTOR::q>(iPop, 1);
        V c2 = descriptors::c<DESCRIPTOR::d, DESCRIPTOR::q>(iPop, 2);
 
        M200 += c0 * c0 * df[iPop];
        M020 += c1 * c1 * df[iPop];
        M002 += c2 * c2 * df[iPop];
 
        M110 += c0 * c1 * df[iPop];
        M011 += c1 * c2 * df[iPop];
        M101 += c0 * c2 * df[iPop];
    }
 
 
      V Nxz = M200 - M002;
      V Nyz = M020 - M002;
 
      V Pxy = M110;
      V Pxz = M101;
      V Pyz = M011;
 
 
      V ds[DESCRIPTOR::q] = {
        0,
        Nxz/3 - Nyz/6, Nyz/3 - Nxz/6, - Nxz/6 - Nyz/6,
        Pxy/4, -Pxy/4, Pxz/4,
        -Pxz/4, Pyz/4, -Pyz/4,
        Nxz/3 - Nyz/6, Nyz/3 - Nxz/6, - Nxz/6 - Nyz/6,
        Pxy/4, -Pxy/4, Pxz/4,
        -Pxz/4, Pyz/4, -Pyz/4,
      };
 
 
      V dh[DESCRIPTOR::q];
      for (int iPop = 0; iPop < DESCRIPTOR::q; ++iPop) {
        dh[iPop] = df[iPop] - ds[iPop];
      }
 
      V beta = omega / 2;
      V dsdh(0);
      V dhdh(0);
      for (int iPop = 0; iPop < DESCRIPTOR::q; ++iPop) {
        dsdh += ds[iPop] * dh[iPop] / fEq[iPop];
        dhdh += dh[iPop] * dh[iPop] / fEq[iPop];
      }
 
      V gamma = dhdh < 1.0e-10 ? 2.0: 1.0/beta - (2 - 1./beta) * dsdh/dhdh;
      //V gamma = 2.0;
 
      cell.template setField<descriptors::GAMMA>(gamma);
      for (int iPop=0; iPop < DESCRIPTOR::q; ++iPop) {
              cell[iPop] -=  beta * (2*ds[iPop] + gamma*dh[iPop]);
      }
 
      return statistic;
    };

References olb::descriptors::c(), and olb::descriptors::t().

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

• src/dynamics/collisionKBC.h