void EulerianParticleVelocityForce
(
cfdemCloud& sm,
const fvMesh& mesh,
volVectorField& Uf_,
volVectorField& Up_,
volScalarField& rho_,
volScalarField& alpf_,
volScalarField& Pg_,
volVectorField& MappedDragForce_,
const labelListList& particleList_,
const bool& weighting_
)
{
// Neighbouring cells
CPCCellToCellStencil neighbourCells(mesh);
// get viscosity field
#ifdef comp
const volScalarField nufField = sm.turbulence().mu()/rho_;
#else
const volScalarField& nufField = sm.turbulence().nu();
#endif
// Gas pressure gradient
volVectorField gradPg_ = fvc::grad(Pg_);
interpolationCellPoint<vector> gradPgInterpolator_(gradPg_);
// Local variables
label cellID(-1);
vector drag(0,0,0);
vector Ufluid(0,0,0);
vector position(0,0,0);
scalar voidfraction(1);
vector Up(0,0,0);
vector Ur(0,0,0);
scalar ds(0);
scalar nuf(0);
scalar rhof(0);
vector WenYuDrag(0,0,0);
interpolationCellPoint<scalar> voidfractionInterpolator_(alpf_);
interpolationCellPoint<vector> UInterpolator_(Uf_);
scalar dist_s(0);
scalar sumWeights(0);
scalarField weightScalar(27,scalar(0.0));
Field <Field <scalar> > particleWeights(particleList_.size(),weightScalar);
//Info << " particle size " << particleList_.size() << endl;
// Number of particle in a cell
scalarField np(mesh.cells().size(),scalar(0));
// Particle volume
scalar Volp(0);
vector gradPg_int(0,0,0);
for(int ii = 0; ii < particleList_.size(); ii++)
{
int index = particleList_[ii][0];
cellID = sm.cellIDs()[index][0];
position = sm.position(index);
Ufluid = UInterpolator_.interpolate(position,cellID);
Up = sm.velocity(index);
Ur = Ufluid-Up;
ds = 2*sm.radius(index);
// Calculate WenYu Drag
voidfraction = voidfractionInterpolator_.interpolate(position,cellID);
nuf = nufField[cellID];
rhof = rho_[cellID];
WenYuDragForce(Ur,ds,rhof,nuf,voidfraction,WenYuDrag);
Volp = ds*ds*ds*M_PI/6;
gradPg_int = gradPgInterpolator_.interpolate(position,cellID);
//if (cellID > -1) // particle centre is in domain
//{
if(weighting_)
{
labelList& cellsNeigh = neighbourCells[cellID];
sumWeights = 0;
dist_s = 0;
//Info << " index = " << index << " ii = " << ii << " cellID = " << cellID << endl;
forAll(cellsNeigh,jj)
{
// Find distances between particle and neighbouring cells
dist_s = mag(sm.mesh().C()[cellsNeigh[jj]]-position)/pow(sm.mesh().V()[cellsNeigh[jj]],1./3.);
if(dist_s <= 0.5)
{
particleWeights[ii][jj] = 1./4.*pow(dist_s,4)-5./8.*pow(dist_s,2)+115./192.;
}
else if (dist_s > 0.5 && dist_s <= 1.5)
{
particleWeights[ii][jj] = -1./6.*pow(dist_s,4)+5./6.*pow(dist_s,3)-5./4.*pow(dist_s,2)+5./24.*dist_s+55./96.;
}
else if (dist_s > 1.5 && dist_s <= 2.5)
{
particleWeights[ii][jj] = pow(2.5-dist_s,4)/24.;
}
else
{
particleWeights[ii][jj] = 0;
}
sumWeights += particleWeights[ii][jj];
}
forAll(cellsNeigh,jj)
{
if ( sumWeights != 0 )
{
Up_[cellID] += Up*particleWeights[ii][jj]/sumWeights;
MappedDragForce_[cellID] += (WenYuDrag + Volp * gradPg_int) * particleWeights[ii][jj]/sumWeights;
}
else
{
Up_[cellID] = vector(0,0,0);
MappedDragForce_[cellID] = vector(0,0,0);
}
}
}
else
{
void CalculateDragForce
(
cfdemCloud& sm,
const volScalarField& alpf_,
const volVectorField& Uf_,
const volScalarField& rho_,
const bool& verbose_,
vectorField& DragForce_,
const labelListList& particleList_
)
{
// get viscosity field
#ifdef comp
const volScalarField nufField = sm.turbulence().mu()/rho_;
#else
const volScalarField& nufField = sm.turbulence().nu();
#endif
// Local variables
label cellI(-1);
vector drag(0,0,0);
vector Ufluid(0,0,0);
vector position(0,0,0);
scalar voidfraction(1);
vector Up(0,0,0);
vector Ur(0,0,0);
scalar ds(0);
scalar nuf(0);
scalar rhof(0);
vector WenYuDrag(0,0,0);
interpolationCellPoint<scalar> voidfractionInterpolator_(alpf_);
interpolationCellPoint<vector> UInterpolator_(Uf_);
//
//_AO_Parallel
DragForce_.resize(particleList_.size());
for(int ii =0; ii < particleList_.size(); ii++)
{
int index = particleList_[ii][0];
cellI = sm.cellIDs()[index][0];
drag = vector(0,0,0);
Ufluid = vector(0,0,0);
WenYuDrag = vector(0,0,0);
DragForce_[ii] = vector(0,0,0);
if (cellI > -1) // particle Found
{
position = sm.position(index);
if ( alpf_[cellI] > 1. ) Pout << " voidfraction > 1 " << alpf_[cellI] << endl;
voidfraction = voidfractionInterpolator_.interpolate(position,cellI);
Ufluid = UInterpolator_.interpolate(position,cellI);
if ( voidfraction > 1. )
{
Pout << " Int. voidfraction > 1 " << " value= " << voidfraction;
voidfraction = alpf_[cellI];
Pout << " mod. value = " << voidfraction << endl;
}
Up = sm.velocity(index);
Ur = Ufluid-Up;
ds = 2*sm.radius(index);
rhof = rho_[cellI];
nuf = nufField[cellI];
// Drag force
WenYuDragForce(Ur,ds,rhof,nuf,voidfraction,WenYuDrag);
if(verbose_ && index <= 1)
{
Info << "" << endl;
Pout << " index = " << index << endl;
Pout << " position = " << position << endl;
Pout << " Up = " << Up << endl;
Pout << " Ur = " << Ur << endl;
Pout << " dp = " << ds << endl;
Pout << " rho = " << rhof << endl;
Pout << " nuf = " << nuf << endl;
Pout << " voidfraction = " << voidfraction << endl;
Pout << " drag = " << WenYuDrag << endl;
Info << " " << endl;
}
}
for(int j=0;j<3;j++) DragForce_[ii][j] = WenYuDrag[j];
}
}
void createParcels
(
const fvMesh& mesh,
cfdemCloud& sm,
const int& parcelSize_,
int**& parcelCloud_,
double**& parcelPositions_,
double**& parcelVelocities_,
int*& parcelNparts_,
double** & parcelKinStress_,
scalar& aveSubQparcel2_,
vector& meanParcelVel_,
const bool verbose_
)
{
if ( parcelSize_ * parcelSize_ * parcelSize_ > sm.numberOfParticles() )
{
FatalError << " Number of particles in a parcel > number of particles" << abort(FatalError);
}
if ( parcelSize_ < 1 )
{
FatalError << " Number of particles < 0 in a parcel " << abort(FatalError);
}
// Number of particles in a parcel
int k = parcelSize_ * parcelSize_ * parcelSize_;
// Dimensions, exact OR approximate
int dim =3; double eps = 0;
// Number of points
int nPts;
nPts = sm.numberOfParticles();
// Data points
ANNpointArray dataPts;
// Query points
ANNpoint queryPt;
ANNidxArray nnIdx; // near neighbour indices
ANNdistArray dists; // near neighbour distances
ANNkd_tree* kdTree; // search structure
// Allocate
queryPt = annAllocPt(dim);
dataPts = annAllocPts(nPts, dim);
nnIdx = new ANNidx[k];
dists = new ANNdist[k];
for(int index = 0; index < sm.numberOfParticles(); index++)
{
dataPts[index][0] = sm.position(index).x();
dataPts[index][1] = sm.position(index).y();
dataPts[index][2] = sm.position(index).z();
}
kdTree = new ANNkd_tree(dataPts, nPts, dim);
// Initialize sub-parcel agitation
aveSubQparcel2_ = 0.;
// Initialize parcel velocity
meanParcelVel_ = vector(0,0,0);
for(int index = 0; index < sm.numberOfParticles(); index++)
{
// Particle neighbouring search distance
scalar sqRad = parcelSize_ * sm.radius(index);
queryPt[0] = sm.position(index).x();
queryPt[1] = sm.position(index).y();
queryPt[2] = sm.position(index).z();
kdTree->annkFRSearch(
queryPt, // query point
sqRad, // squared radius
k, // number of the near neighbours to return
nnIdx, // nearest neighbor array
dists, // dist to near neighbours
eps );
int nParts = 0;
scalar dist = 0;
// Initialize parcel velocities & positions & kinetic stresses
for(int j=0;j<3;j++)
{
parcelVelocities_[index][j] = 0.;
parcelPositions_[index][j] = 0.;
parcelKinStress_[index][j] = 0.;
parcelKinStress_[index][2*j] = 0.;
}
for (int i = 0; i < k; i++)
{
parcelCloud_[index][i] = nnIdx[i];
dist = mag( sm.position(nnIdx[i]) - sm.position(index) ) - sqRad;
if ( dist < SMALL )
{
for(int j=0;j<3;j++)
{
// Parcel velocity
parcelVelocities_[index][j] += sm.velocity(nnIdx[i])[j];
// Parcel center of mass
parcelPositions_[index][j] += sm.position(nnIdx[i])[j];
}
nParts++;
}
}
for(int j=0;j<3;j++) parcelPositions_[index][j] /= nParts;
parcelNparts_[index] = nParts;
// Parcel kinetic stresses
for(int i = 0; i < parcelNparts_[index]; i++)
{
int particleID = parcelCloud_[index][i];
// U'xU'x
parcelKinStress_[index][0] += ( sm.velocity(particleID)[0] - parcelVelocities_[index][0] )
*( sm.velocity(particleID)[0] - parcelVelocities_[index][0] );
// U'yU'y
parcelKinStress_[index][1] += ( sm.velocity(particleID)[1] - parcelVelocities_[index][1] )
*( sm.velocity(particleID)[1] - parcelVelocities_[index][1] );
// U'zU'z
parcelKinStress_[index][2] += ( sm.velocity(particleID)[2] - parcelVelocities_[index][2] )
*( sm.velocity(particleID)[2] - parcelVelocities_[index][2] );
// U'xU'y
parcelKinStress_[index][3] += ( sm.velocity(particleID)[0] - parcelVelocities_[index][0] )
*( sm.velocity(particleID)[1] - parcelVelocities_[index][1] );
// U'xU'z
parcelKinStress_[index][4] += ( sm.velocity(particleID)[0] - parcelVelocities_[index][0] )
*( sm.velocity(particleID)[2] - parcelVelocities_[index][2] );
// U'yU'z
parcelKinStress_[index][5] += ( sm.velocity(particleID)[1] - parcelVelocities_[index][1] )
*( sm.velocity(particleID)[2] - parcelVelocities_[index][2] );
}
// Mean parcel velocity
for(int j=0;j<3;j++) meanParcelVel_[j] += parcelVelocities_[index][j];
// Domain-averaged parcel agitation
aveSubQparcel2_ += 1./2. * ( parcelKinStress_[index][0] + parcelKinStress_[index][1] + parcelKinStress_[index][2] );
}
for(int j=0;j<3;j++) meanParcelVel_[j] /= sm.numberOfParticles();
if ( verbose_ )
{
int index = 0;
Info << " Parcel particle list ";
for (int i = 0; i < parcelNparts_[index]; i++)
{
Info << parcelCloud_[index][i] << " " ;
}
Info << endl;
Info << " Parcel center " << parcelPositions_[index][0] << "," << parcelPositions_[index][1] << "," << parcelPositions_[index][2] << endl;
Info << " Parcel velocity " << parcelVelocities_[index][0] << "," << parcelVelocities_[index][1] << "," << parcelVelocities_[index][2] << endl;
for (int i = 0; i < parcelNparts_[index]; i++)
{
Info << " Particle " << parcelCloud_[index][i] << endl;
Info << " Particle center " << sm.position(parcelCloud_[index][i]) << endl;
Info << " Particle velocity " << sm.velocity(parcelCloud_[index][i]) << endl;
}
}
}
