olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM > Struct Template Reference

#include <collisionLES.h>

Collaboration diagram for olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >:

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

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

Detailed Description

template<typename COLLISION, typename DESCRIPTOR, typename MOMENTA, typename EQUILIBRIUM>
struct olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >

Definition at line 359 of file collisionLES.h.

Member Typedef Documentation

CollisionO

template<typename COLLISION , typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

using olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >::CollisionO = typename COLLISION::template type<DESCRIPTOR, MOMENTA, EQUILIBRIUM>

Definition at line 361 of file collisionLES.h.

MomentaF

template<typename COLLISION , typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

using olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >::MomentaF = typename MOMENTA::template type<DESCRIPTOR>

Definition at line 360 of file collisionLES.h.

Member Function Documentation

apply()

template<typename COLLISION , typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

template<concepts::Cell CELL, concepts::Parameters PARAMETERS, typename V = typename CELL::value_t>

CellStatistic< V > olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >::apply ( CELL & cell, PARAMETERS & parameters )

inline

Definition at line 437 of file collisionLES.h.

                                                                          {
    parameters.template set<descriptors::OMEGA>(
      computeEffectiveOmega(cell, parameters));
    return CollisionO().apply(cell, parameters);
  }

References olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >::computeEffectiveOmega().

Here is the call graph for this function:

computeEffectiveOmega()

template<typename COLLISION , typename DESCRIPTOR , typename MOMENTA , typename EQUILIBRIUM >

template<concepts::Cell CELL, concepts::Parameters PARAMETERS, typename V = typename CELL::value_t>

V olb::collision::detail::WaleEffectiveOmega< COLLISION, DESCRIPTOR, MOMENTA, EQUILIBRIUM >::computeEffectiveOmega ( CELL & cell, PARAMETERS & parameters )

inline

Molecular relaxation time

Effective relaxation time

Definition at line 364 of file collisionLES.h.

                                                                           {
    V piNeqNormSqr { };
    MomentaF().computePiNeqNormSqr(cell, piNeqNormSqr);
    const V omega = parameters.template get<descriptors::OMEGA>();
    const V smagorinsky = parameters.template get<collision::LES::SMAGORINSKY>();
    const auto velocityGradient = cell.template getField<descriptors::VELO_GRAD>();
    V preFactor = smagorinsky*smagorinsky;
    // velocity gradient tensor
    V g[3][3];
    for (unsigned i=0; i < 3; i++) {
      for (unsigned j=0; j < 3; j++) {
        g[i][j] = velocityGradient[i*3 + j];
      }
    }
    // strain rate tensor
    V s[3][3];
    for (unsigned i = 0; i < 3; i++) {
      for (unsigned j = 0; j < 3; j++) {
        s[i][j] = (g[i][j] + g[j][i]) / V{2};
      }
    }
    // traceless symmetric part of the square of the velocity gradient tensor
    V G[3][3];
    for (unsigned i = 0; i < 3; i++) {
      for (unsigned j = 0; j < 3; j++) {
        G[i][j] = V{0};
      }
    }
    for (unsigned i = 0; i < 3; i++) {
      for (unsigned j = 0; j < 3; j++) {
        for (unsigned k = 0; k < 3; k++) {
          G[i][j] += (g[i][k]*g[k][j] + g[j][k]*g[k][i]) / V{2};
        }
      }
    }
    V trace{};
    for (unsigned i = 0; i < 3; i++) {
      trace += V{1}/V{3} * g[i][i] * g[i][i];
    }
    for (unsigned i = 0; i < 3; i++) {
      G[i][i] -= trace;
    }
    // inner product of the traceless symmetric part of the square of the velocity gradient tensor
    V G_ip{};
    for (unsigned i = 0; i < 3; i++) {
      for (unsigned j = 0; j < 3; j++) {
        G_ip = G[i][j] * G[i][j];
      }
    }
    // inner product of the strain rate
    V s_ip{};
    for (unsigned i = 0; i < 3; i++) {
      for (unsigned j = 0; j < 3; j++) {
        s_ip = s[i][j] * s[i][j];
      }
    }
    // Turbulent relaxation time
    V tauTurb = V{3} * preFactor * (util::pow(G_ip,1.5) / (util::pow(s_ip,2.5) + util::pow(G_ip,1.25)));
    if ((util::pow(s_ip,2.5) + util::pow(G_ip,1.25)) == 0) {
      tauTurb = 0;
    }
    // Physical turbulent viscosity must be equal or higher that zero
    if (tauTurb < 0) {
      tauTurb = 0;
    }
    V tauMol = V{1} / omega;
    V tauEff = tauMol + tauTurb;
    return V{1} / tauEff;
  }

References olb::util::pow().

Here is the call graph for this function:

Here is the caller graph for this function:

---

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

• src/dynamics/collisionLES.h