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 DiFeliceDrag::setForce() const
{
if (scaleDia_ > 1)
Info << typeName << " using scale = " << scaleDia_ << endl;
else if (particleCloud_.cg() > 1){
scaleDia_=particleCloud_.cg();
Info << typeName << " using scale from liggghts cg = " << scaleDia_ << endl;
}
const volScalarField& nufField = forceSubM(0).nuField();
const volScalarField& rhoField = forceSubM(0).rhoField();
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 nuf(0);
scalar rho(0);
scalar magUr(0);
scalar Rep(0);
scalar Cd(0);
interpolationCellPoint<scalar> voidfractionInterpolator_(voidfraction_);
interpolationCellPoint<vector> UInterpolator_(U_);
#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);
Ufluid =vector(0,0,0);
if (cellI > -1) // particle Found
{
if(forceSubM(0).interpolation())
{
position = particleCloud_.position(index);
voidfraction = voidfractionInterpolator_.interpolate(position,cellI);
Ufluid = UInterpolator_.interpolate(position,cellI);
}else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
Us = particleCloud_.velocity(index);
Ur = Ufluid-Us;
ds = 2*particleCloud_.radius(index);
nuf = nufField[cellI];
rho = rhoField[cellI];
magUr = mag(Ur);
Rep = 0;
Cd = 0;
dragCoefficient = 0;
if (magUr > 0)
{
// calc particle Re Nr
Rep = ds/scaleDia_*voidfraction*magUr/(nuf+SMALL);
// calc fluid drag Coeff
Cd = sqr(0.63 + 4.8/sqrt(Rep));
// calc model coefficient Xi
scalar Xi = 3.7 - 0.65 * exp(-sqr(1.5-log10(Rep))/2);
// calc particle's drag
dragCoefficient = 0.125*Cd*rho
*M_PI
*ds*ds
*scaleDia_
*pow(voidfraction,(2-Xi))*magUr
*scaleDrag_;
if (modelType_=="B")
dragCoefficient /= voidfraction;
drag = dragCoefficient*Ur; //total drag force!
forceSubM(0).explicitCorr(drag,dragExplicit,dragCoefficient,Ufluid,U_[cellI],Us,UsField_[cellI],forceSubM(0).verbose(),index);
}
if(forceSubM(0).verbose() && index >-1 && index <102)
{
Pout << "index = " << index << endl;
Pout << "scaleDrag_ = " << scaleDrag_ << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "ds/scale = " << ds/scaleDia_ << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "voidfraction = " << voidfraction << endl;
Pout << "Rep = " << Rep << endl;
Pout << "Cd = " << Cd << endl;
Pout << "drag (total) = " << 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(Cd);
sValues.append(voidfraction);
particleCloud_.probeM().writeProbe(index, sValues, vValues);
}
}
// write particle based data to global array
forceSubM(0).partToArray(index,drag,dragExplicit,Ufluid,dragCoefficient);
}
}
void DiFeliceDrag::setForce() const
{
if (scaleDia_ > 1)
Info << "DiFeliceDrag using scale = " << scaleDia_ << endl;
else if (particleCloud_.cg() > 1){
scaleDia_=particleCloud_.cg();
Info << "DiFeliceDrag 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 Cd(0);
vector UfluidFluct(0,0,0);
vector UsFluct(0,0,0);
vector dragExplicit(0,0,0);
scalar dragCoefficient(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);
if (cellI > -1) // particle Found
{
if(interpolation_)
{
position = particleCloud_.position(index);
voidfraction = voidfractionInterpolator_.interpolate(position,cellI);
Ufluid = UInterpolator_.interpolate(position,cellI);
}else
{
voidfraction = voidfraction_[cellI];
Ufluid = U_[cellI];
}
Us = particleCloud_.velocity(index);
Ur = Ufluid-Us;
ds = 2*particleCloud_.radius(index);
nuf = nufField[cellI];
rho = rho_[cellI];
magUr = mag(Ur);
Rep = 0;
Cd = 0;
dragCoefficient = 0;
if (magUr > 0)
{
// calc particle Re Nr
Rep = ds/scaleDia_*voidfraction*magUr/(nuf+SMALL);
// calc fluid drag Coeff
Cd = sqr(0.63 + 4.8/sqrt(Rep));
// calc model coefficient Xi
scalar Xi = 3.7 - 0.65 * exp(-sqr(1.5-log10(Rep))/2);
// calc particle's drag
dragCoefficient = 0.125*Cd*rho
*M_PI
*ds*ds
*scaleDia_
*pow(voidfraction,(2-Xi))*magUr
*scaleDrag_;
if (modelType_=="B")
dragCoefficient /= voidfraction;
drag = dragCoefficient*Ur; //total drag force!
//Split forces
if(splitImplicitExplicit_)
{
UfluidFluct = Ufluid - U_[cellI];
UsFluct = Us - UsField_[cellI];
dragExplicit = dragCoefficient*(UfluidFluct - UsFluct); //explicit part of force
}
}
if(verbose_ && index >-1 && index <102)
{
Pout << "index = " << index << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "ds/scale = " << ds/scaleDia_ << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "voidfraction = " << voidfraction << endl;
Pout << "Rep = " << Rep << endl;
Pout << "Cd = " << Cd << endl;
Pout << "drag (total) = " << drag << endl;
if(splitImplicitExplicit_)
{
Pout << "UfluidFluct = " << UfluidFluct << endl;
Pout << "UsFluct = " << UsFluct << endl;
Pout << "dragExplicit = " << dragExplicit << 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(Cd);
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 //implicit treatment, taking explicit force contribution into account
{
for(int j=0;j<3;j++)
{
impForces()[index][j] += drag[j] - dragExplicit[j]; //only consider implicit part!
expForces()[index][j] += dragExplicit[j];
}
}
for(int j=0;j<3;j++) DEMForces()[index][j] += drag[j];
}
//}
}
