void BeetstraDrag::setForce() const
{
scale_=cg();
Info << "BeetstraDrag using scale from liggghts cg = " << scale_ << endl;
// get viscosity field
#ifdef comp
const volScalarField nufField = particleCloud_.turbulence().mu()/rho_;
#else
const volScalarField& nufField = particleCloud_.turbulence().nu();
#endif
vector position(0,0,0);
scalar voidfraction(1);
vector Ufluid(0,0,0);
vector drag(0,0,0);
label cellI=0;
scalar beta(0);
vector Us(0,0,0);
vector Ur(0,0,0);
scalar ds(0);
scalar nuf(0);
scalar rho(0);
scalar magUr(0);
scalar Rep(0);
scalar Vs(0);
scalar localPhiP(0);
scalar filterDragPrefactor(1.0);
scalar cCorrParcelSize_(1.0) ;
scalar vCell(0);
scalar FfFilterPrime(1);
scalar F0=0.;
scalar G0=0.;
interpolationCellPoint<scalar> voidfractionInterpolator_(voidfraction_);
interpolationCellPoint<vector> UInterpolator_(U_);
#include "setupProbeModel.H"
for(int index = 0;index < particleCloud_.numberOfParticles(); index++)
{
//if(mask[index][0])
//{
cellI = particleCloud_.cellIDs()[index][0];
drag = vector(0,0,0);
Ufluid= vector(0,0,0);
if (cellI > -1) // particle Found
{
if(interpolation_)
{
position = particleCloud_.position(index);
voidfraction = voidfractionInterpolator_.interpolate(position,cellI);
Ufluid = UInterpolator_.interpolate(position,cellI);
//Ensure interpolated void fraction to be meaningful
// Info << " --> voidfraction: " << voidfraction << endl;
if(voidfraction>1.00) voidfraction = 1.00;
if(voidfraction<0.10) voidfraction = 0.10;
}
else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
Us = particleCloud_.velocity(index);
Ur = Ufluid-Us;
ds = 2*particleCloud_.radius(index);
dPrim_ = ds/scale_;
nuf = nufField[cellI];
rho = rho_[cellI];
magUr = mag(Ur);
Rep = 0;
Vs = ds*ds*ds*M_PI/6;
localPhiP = 1-voidfraction+SMALL;
vCell = U_.mesh().V()[cellI];
if (magUr > 0)
{
// calc particle Re Nr
Rep = dPrim_*voidfraction*magUr/(nuf+SMALL);
// 3 - C - 1 - In this section we could insert parameters
// or functions
// that come from a database
// calc model coefficient F0
F0 = 10.f * localPhiP / voidfraction / voidfraction
+ voidfraction * voidfraction * ( 1.0+1.5*sqrt(localPhiP) );
// calc model coefficient G0
G0 = 0.01720833 * Rep / voidfraction / voidfraction //0.0172083 = 0.413/24
* ( 1.0 / voidfraction + 3.0 * localPhiP * voidfraction + 8.4
* powf(Rep,-0.343) )
/ ( 1.0 + powf( 10., 3.0* localPhiP )
* powf( Rep,-(1.0+4.0*localPhiP)/2.0 ) );
// calc model coefficient beta
beta = 18.*nuf*rho/(dPrim_*dPrim_)
*voidfraction
*(F0 + G0);
//Apply filtered drag correction
if(useFilteredDragModel_)
{
FfFilterPrime = FfFilterFunc(
filtDragParamsLChar2_,
vCell,
0
);
filterDragPrefactor = 1 - fFuncFilteredDrag(FfFilterPrime, localPhiP)
* hFuncFilteredDrag(localPhiP);
beta *= filterDragPrefactor;
}
if(useParcelSizeDependentFilteredDrag_) //Apply filtered drag correction
{
scalar dParceldPrim = scale_;
cCorrParcelSize_ =
cCorrFunctionFilteredDrag(
filtDragParamsK_,
filtDragParamsALimit_,
filtDragParamsAExponent_,
localPhiP,
dParceldPrim
);
beta *= cCorrParcelSize_;
}
// calc particle's drag
drag = Vs * beta * Ur;
if (modelType_=="B")
drag /= voidfraction;
}
// 3 - C - 2 - This is a standardized debug and report section
if( verbose_ ) //&& index>100 && index < 105)
{
Info << "index / cellI = " << index << tab << cellI << endl;
Info << "position = " << particleCloud_.position(index) << endl;
Info << "Us = " << Us << endl;
Info << "Ur = " << Ur << endl;
Info << "ds = " << ds << endl;
Info << "rho = " << rho << endl;
Info << "nuf = " << nuf << endl;
Info << "voidfraction = " << voidfraction << endl;
Info << "voidfraction_[cellI]: " << voidfraction_[cellI] << endl;
Info << "Rep = " << Rep << endl;
Info << "filterDragPrefactor = " << filterDragPrefactor << endl;
Info << "fFuncFilteredDrag: " << fFuncFilteredDrag(FfFilterPrime, localPhiP) << endl;
Info << "hFuncFilteredDrag: " << hFuncFilteredDrag(localPhiP) << endl;
Info << "cCorrParcelSize: " << cCorrParcelSize_ << endl;
Info << "F0 / G0: " << F0 << tab << G0 << endl;
Info << "beta: " << beta << endl;
Info << "drag = " << drag << endl;
Info << "\nBeetstra drag model settings: treatExplicit " << treatExplicit_ << tab
<< "verbose: " << verbose_ << tab
<< "dPrim: " << dPrim_ << tab
<< "interpolation: " << interpolation_ << tab
<< "filteredDragM: " << useFilteredDragModel_ << tab
<< "parcelSizeDepDrag: " << useParcelSizeDependentFilteredDrag_
<< endl << endl;
}
//Set value fields and write the probe
if(probeIt_)
{
#include "setupProbeModelfields.H"
vValues.append(drag); //first entry must the be the force
vValues.append(Ur);
sValues.append(Rep);
sValues.append(beta);
sValues.append(voidfraction);
sValues.append(filterDragPrefactor);
particleCloud_.probeM().writeProbe(index, sValues, vValues);
}
}
// set force on particle
if(treatExplicit_) for(int j=0;j<3;j++) expForces()[index][j] += drag[j];
else for(int j=0;j<3;j++) impForces()[index][j] += drag[j];
// set Cd
if(implDEM_)
{
for(int j=0;j<3;j++) fluidVel()[index][j]=Ufluid[j];
if (modelType_=="B")
Cds()[index][0] = Vs*beta/voidfraction;
else
Cds()[index][0] = Vs*beta;
}else{
for(int j=0;j<3;j++) DEMForces()[index][j] += drag[j];
}
//}
}
}
void GidaspowDrag::setForce() const
{
if (scaleDia_ > 1)
Info << "Gidaspow using scale = " << scaleDia_ << endl;
else if (particleCloud_.cg() > 1){
scaleDia_=particleCloud_.cg();
Info << "Gidaspow using scale from liggghts cg = " << scaleDia_ << endl;
}
// get viscosity field
#ifdef comp
const volScalarField nufField = particleCloud_.turbulence().mu() / rho_;
#else
const volScalarField& nufField = particleCloud_.turbulence().nu();
#endif
vector position(0,0,0);
scalar voidfraction(1);
vector Ufluid(0,0,0);
vector drag(0,0,0);
label cellI=0;
vector Us(0,0,0);
vector Uturb(0,0,0);
vector Ur(0,0,0);
scalar ds(0);
scalar nuf(0);
scalar rho(0);
scalar magUr(0);
scalar Rep(0);
scalar Vs(0);
scalar localPhiP(0);
scalar CdMagUrLag(0); //Cd of the very particle
scalar KslLag(0); //momentum exchange of the very particle (per unit volume)
scalar betaP(0); //momentum exchange of the very particle
interpolationCellPoint<scalar> voidfractionInterpolator_(voidfraction_);
interpolationCellPoint<vector> UInterpolator_(U_);
#include "setupProbeModel.H"
for(int index = 0;index < particleCloud_.numberOfParticles(); ++index)
{
//if(mask[index][0])
//{
cellI = particleCloud_.cellIDs()[index][0];
drag = vector(0,0,0);
betaP = 0;
Vs = 0;
Ufluid =vector(0,0,0);
voidfraction=0;
if (cellI > -1) // particle Found
{
position = particleCloud_.position(index);
if(interpolation_)
{
//position = particleCloud_.position(index);
voidfraction = voidfractionInterpolator_.interpolate(position,cellI);
Ufluid = UInterpolator_.interpolate(position,cellI);
//Ensure interpolated void fraction to be meaningful
// Info << " --> voidfraction: " << voidfraction << endl;
if(voidfraction>1.00) voidfraction = 1.0;
if(voidfraction<0.10) voidfraction = 0.10;
}
else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
Us = particleCloud_.velocity(index);
Ur = Ufluid-Us;
//accounting for turbulent dispersion
if(particleCloud_.dispersionM().isActive())
{
Uturb=particleCloud_.fluidTurbVel(index);
Ur=(Ufluid+Uturb)-Us;
}
magUr = mag(Ur);
ds = 2*particleCloud_.radius(index)*phi_;
rho = rho_[cellI];
nuf = nufField[cellI];
Rep=0.0;
localPhiP = 1.0f-voidfraction+SMALL;
Vs = ds*ds*ds*M_PI/6;
//Compute specific drag coefficient (i.e., Force per unit slip velocity and per m³ SUSPENSION)
//Wen and Yu, 1966
if(voidfraction > 0.8) //dilute
{
Rep=ds/scaleDia_*voidfraction*magUr/nuf;
CdMagUrLag = (24.0*nuf/(ds/scaleDia_*voidfraction)) //1/magUr missing here, but compensated in expression for KslLag!
*(scalar(1)+0.15*Foam::pow(Rep, 0.687));
KslLag = 0.75*(
rho*localPhiP*voidfraction*CdMagUrLag
/
(ds/scaleDia_*Foam::pow(voidfraction,2.65))
);
}
//Ergun, 1952
else //dense
{
KslLag = (150*Foam::pow(localPhiP,2)*nuf*rho)/
(voidfraction*ds/scaleDia_*ds/scaleDia_+SMALL)
+
(1.75*(localPhiP) * magUr * rho)/
((ds/scaleDia_));
}
// calc particle's drag coefficient (i.e., Force per unit slip velocity and per m³ PARTICLE)
betaP = KslLag / localPhiP;
// calc particle's drag
drag = Vs * betaP * Ur * scaleDrag_;
if (modelType_=="B")
drag /= voidfraction;
if(verbose_ && index >=0 && index <1)
{
Pout << " "<< endl;
Pout << "Gidaspow drag force verbose: " << endl;
Pout << "magUr = " << magUr << endl;
Pout << "localPhiP = " << localPhiP << endl;
Pout << "CdMagUrLag = " << CdMagUrLag << endl;
Pout << "treatExplicit_ = " << treatExplicit_ << endl;
Pout << "implDEM_ = " << implDEM_ << endl;
Pout << "modelType_ = " << modelType_ << endl;
Pout << "KslLag = " << KslLag << endl;
Pout << "cellI = " << cellI << endl;
Pout << "index = " << index << endl;
Pout << "Ufluid = " << Ufluid << endl;
Pout << "Uturb = " << Uturb << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "Vs = " << Vs << endl;
Pout << "ds = " << ds << endl;
Pout << "ds/scale = " << ds/scaleDia_ << endl;
Pout << "phi = " << phi_ << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "voidfraction = " << voidfraction << endl;
Pout << "Rep = " << Rep << endl;
Pout << "localPhiP = " << localPhiP << endl;
Pout << "betaP = " << betaP << endl;
Pout << "drag = " << drag << endl;
Pout << "position = " << position << endl;
Pout << " "<< endl;
}
//Set value fields and write the probe
if(probeIt_)
{
#include "setupProbeModelfields.H"
vValues.append(drag); //first entry must the be the force
vValues.append(Ur);
sValues.append(Rep);
sValues.append(betaP);
sValues.append(voidfraction);
particleCloud_.probeM().writeProbe(index, sValues, vValues);
}
}
// set force on particle
//treatExplicit_ = false by default
if(treatExplicit_) for(int j=0;j<3;j++) expForces()[index][j] += drag[j];
else for(int j=0;j<3;j++) impForces()[index][j] += drag[j];
// set Cd
//implDEM_ = false by default
if(implDEM_)
{
for(int j=0;j<3;j++) fluidVel()[index][j]=Ufluid[j];
if (modelType_=="B" && cellI > -1)
Cds()[index][0] = Vs*betaP/voidfraction*scaleDrag_;
else
Cds()[index][0] = Vs*betaP*scaleDrag_;
}else{
for(int j=0;j<3;j++) DEMForces()[index][j] += drag[j];
}
//}// end if mask
}// end loop particles
}
