void KochHillDrag::setForce() const
{
const volScalarField& nufField = forceSubM(0).nuField();
const volScalarField& rhoField = forceSubM(0).rhoField();
//update force submodels to prepare for loop
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).preParticleLoop(forceSubM(iFSub).verbose());
vector position(0,0,0);
scalar voidfraction(1);
vector Ufluid(0,0,0);
vector drag(0,0,0);
vector dragExplicit(0,0,0);
scalar dragCoefficient(0);
label cellI=0;
vector Us(0,0,0);
vector Ur(0,0,0);
scalar ds(0);
scalar dParcel(0);
scalar nuf(0);
scalar rho(0);
scalar magUr(0);
scalar Rep(0);
scalar Vs(0);
scalar volumefraction(0);
scalar betaP(0);
scalar piBySix(M_PI/6);
int couplingInterval(particleCloud_.dataExchangeM().couplingInterval());
#include "resetVoidfractionInterpolator.H"
#include "resetUInterpolator.H"
#include "setupProbeModel.H"
for(int index = 0;index < particleCloud_.numberOfParticles(); index++)
{
cellI = particleCloud_.cellIDs()[index][0];
drag = vector(0,0,0);
dragExplicit = vector(0,0,0);
dragCoefficient=0;
betaP = 0;
Vs = 0;
Ufluid =vector(0,0,0);
voidfraction=0;
if (cellI > -1) // particle Found
{
if(forceSubM(0).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<0.40) voidfraction = 0.40;
}else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
ds = particleCloud_.d(index);
dParcel = ds;
forceSubM(0).scaleDia(ds); //caution: this fct will scale ds!
nuf = nufField[cellI];
rho = rhoField[cellI];
Us = particleCloud_.velocity(index);
//Update any scalar or vector quantity
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).update( index,
cellI,
ds,
Ufluid,
Us,
nuf,
rho,
forceSubM(0).verbose()
);
Ur = Ufluid-Us;
magUr = mag(Ur);
Rep = 0;
Vs = ds*ds*ds*piBySix;
volumefraction = max(SMALL,min(1-SMALL,1-voidfraction));
if (magUr > 0)
{
// calc particle Re Nr
Rep = ds*voidfraction*magUr/(nuf+SMALL);
// calc model coefficient F0
scalar F0=0.;
if(volumefraction < 0.4)
{
F0 = (1. + 3.*sqrt((volumefraction)/2.) + (135./64.)*volumefraction*log(volumefraction)
+ 16.14*volumefraction
)/
(1+0.681*volumefraction-8.48*sqr(volumefraction)
+8.16*volumefraction*volumefraction*volumefraction
);
} else {
F0 = 10*volumefraction/(voidfraction*voidfraction*voidfraction);
}
// calc model coefficient F3
scalar F3 = 0.0673+0.212*volumefraction+0.0232/pow(voidfraction,5);
//Calculate F (the factor 0.5 is introduced, since Koch and Hill, ARFM 33:619–47, use the radius
//to define Rep, and we use the particle diameter, see vanBuijtenen et al., CES 66:2368–2376.
scalar F = voidfraction * (F0 + 0.5*F3*Rep);
// calc drag model coefficient betaP
betaP = 18.*nuf*rho/(ds*ds)*voidfraction*F;
// calc particle's drag
dragCoefficient = Vs*betaP;
if (modelType_=="B")
dragCoefficient /= voidfraction;
forceSubM(0).scaleCoeff(dragCoefficient,dParcel);
if(forceSubM(0).switches()[7]) // implForceDEMaccumulated=true
{
//get drag from the particle itself
for (int j=0 ; j<3 ; j++) drag[j] = particleCloud_.fAccs()[index][j]/couplingInterval;
}else
{
drag = dragCoefficient * Ur;
// explicitCorr
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).explicitCorr( drag,
dragExplicit,
dragCoefficient,
Ufluid, U_[cellI], Us, UsField_[cellI],
forceSubM(iFSub).verbose()
);
}
}
if(forceSubM(0).verbose() && index >=0 && index <2)
{
Pout << "cellI = " << cellI << endl;
Pout << "index = " << index << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "dprim = " << ds << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "voidfraction = " << voidfraction << endl;
Pout << "Rep = " << Rep << endl;
Pout << "betaP = " << betaP << endl;
Pout << "drag = " << drag << endl;
}
//Set value fields and write the probe
if(probeIt_)
{
#include "setupProbeModelfields.H"
// Note: for other than ext one could use vValues.append(x)
// instead of setSize
vValues.setSize(vValues.size()+1, drag); //first entry must the be the force
vValues.setSize(vValues.size()+1, Ur);
sValues.setSize(sValues.size()+1, Rep);
sValues.setSize(sValues.size()+1, betaP);
sValues.setSize(sValues.size()+1, voidfraction);
particleCloud_.probeM().writeProbe(index, sValues, vValues);
}
}
// write particle based data to global array
forceSubM(0).partToArray(index,drag,dragExplicit,Ufluid,dragCoefficient);
}
}
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
}
void KochHillDrag::setForce() const
{
if (scaleDia_ > 1)
Info << "KochHill using scale = " << scaleDia_ << endl;
else if (particleCloud_.cg() > 1){
scaleDia_=particleCloud_.cg();
Info << "KochHill 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 Ur(0,0,0);
scalar ds(0);
scalar nuf(0);
scalar rho(0);
scalar magUr(0);
scalar Rep(0);
scalar Vs(0);
scalar volumefraction(0);
scalar betaP(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);
betaP = 0;
Vs = 0;
Ufluid =vector(0,0,0);
voidfraction=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<0.40) voidfraction = 0.40;
}else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
Us = particleCloud_.velocity(index);
Ur = Ufluid-Us;
ds = particleCloud_.d(index);
nuf = nufField[cellI];
rho = rho_[cellI];
magUr = mag(Ur);
Rep = 0;
Vs = ds*ds*ds*M_PI/6;
volumefraction = 1-voidfraction+SMALL;
if (magUr > 0)
{
// calc particle Re Nr
Rep = ds/scaleDia_*voidfraction*magUr/(nuf+SMALL);
// calc model coefficient F0
scalar F0=0.;
if(volumefraction < 0.4)
{
F0 = (1+3*sqrt((volumefraction)/2)+135/64*volumefraction*log(volumefraction)
+16.14*volumefraction
)/
(1+0.681*volumefraction-8.48*sqr(volumefraction)
+8.16*volumefraction*volumefraction*volumefraction
);
} else {
F0 = 10*volumefraction/(voidfraction*voidfraction*voidfraction);
}
// calc model coefficient F3
scalar F3 = 0.0673+0.212*volumefraction+0.0232/pow(voidfraction,5);
//Calculate F
scalar F = voidfraction * (F0 + 0.5*F3*Rep);
// calc drag model coefficient betaP
betaP = 18.*nuf*rho/(ds/scaleDia_*ds/scaleDia_)*voidfraction*F;
// calc particle's drag
drag = Vs*betaP*Ur*scaleDrag_;
if (modelType_=="B")
drag /= voidfraction;
}
if(verbose_ && index >=0 && index <2)
{
Pout << "cellI = " << cellI << endl;
Pout << "index = " << index << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "ds = " << ds << endl;
Pout << "ds/scale = " << ds/scaleDia_ << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "voidfraction = " << voidfraction << endl;
Pout << "Rep = " << Rep << endl;
Pout << "betaP = " << betaP << endl;
Pout << "drag = " << drag << 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
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" && 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];
}
//}
}
}
