// Construct from components
KochHillDrag::KochHillDrag
(
const dictionary& dict,
cfdemCloud& sm
)
:
forceModel(dict,sm),
propsDict_(dict.subDict(typeName + "Props")),
velFieldName_(propsDict_.lookup("velFieldName")),
U_(sm.mesh().lookupObject<volVectorField> (velFieldName_)),
voidfractionFieldName_(propsDict_.lookup("voidfractionFieldName")),
voidfraction_(sm.mesh().lookupObject<volScalarField> (voidfractionFieldName_)),
UsFieldName_(propsDict_.lookupOrDefault("granVelFieldName",word("Us"))),
UsField_(sm.mesh().lookupObject<volVectorField> (UsFieldName_))
{
// suppress particle probe
if (probeIt_ && propsDict_.found("suppressProbe"))
probeIt_=!Switch(propsDict_.lookup("suppressProbe"));
if(probeIt_)
{
particleCloud_.probeM().initialize(typeName, typeName+".logDat");
particleCloud_.probeM().vectorFields_.append("dragForce"); //first entry must the be the force
particleCloud_.probeM().vectorFields_.append("Urel"); //other are debug
particleCloud_.probeM().scalarFields_.append("Rep"); //other are debug
particleCloud_.probeM().scalarFields_.append("beta"); //other are debug
particleCloud_.probeM().scalarFields_.append("voidfraction"); //other are debug
particleCloud_.probeM().writeHeader();
}
// init force sub model
setForceSubModels(propsDict_);
// define switches which can be read from dict
forceSubM(0).setSwitchesList(0,true); // activate search for treatExplicit switch
forceSubM(0).setSwitchesList(2,true); // activate search for implDEM switch
forceSubM(0).setSwitchesList(3,true); // activate search for verbose switch
forceSubM(0).setSwitchesList(4,true); // activate search for interpolate switch
forceSubM(0).setSwitchesList(7,true); // activate implForceDEMacc switch
forceSubM(0).setSwitchesList(8,true); // activate scalarViscosity switch
// read those switches defined above, if provided in dict
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).readSwitches();
particleCloud_.checkCG(true);
}
// Construct from components
MeiLift::MeiLift
(
const dictionary& dict,
cfdemCloud& sm
)
:
forceModel(dict,sm),
propsDict_(dict.subDict(typeName + "Props")),
velFieldName_(propsDict_.lookup("velFieldName")),
U_(sm.mesh().lookupObject<volVectorField> (velFieldName_)),
useSecondOrderTerms_(false)
{
if (propsDict_.found("useSecondOrderTerms")) useSecondOrderTerms_=true;
// init force sub model
setForceSubModels(propsDict_);
// define switches which can be read from dict
forceSubM(0).setSwitchesList(0,true); // activate treatExplicit switch
forceSubM(0).setSwitchesList(3,true); // activate search for verbose switch
forceSubM(0).setSwitchesList(4,true); // activate search for interpolate switch
forceSubM(0).setSwitchesList(8,true); // activate scalarViscosity switch
//set default switches (hard-coded default = false)
forceSubM(0).setSwitches(0,true); // enable treatExplicit, otherwise this force would be implicit in slip vel! - IMPORTANT!
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).readSwitches();
particleCloud_.checkCG(false);
//Append the field names to be probed
particleCloud_.probeM().initialize(typeName, typeName+".logDat");
particleCloud_.probeM().vectorFields_.append("liftForce"); //first entry must the be the force
particleCloud_.probeM().vectorFields_.append("Urel"); //other are debug
particleCloud_.probeM().vectorFields_.append("vorticity"); //other are debug
particleCloud_.probeM().scalarFields_.append("Rep"); //other are debug
particleCloud_.probeM().scalarFields_.append("Rew"); //other are debug
particleCloud_.probeM().scalarFields_.append("J_star"); //other are debug
particleCloud_.probeM().writeHeader();
}
void MeiLift::setForce() const
{
const volScalarField& nufField = forceSubM(0).nuField();
const volScalarField& rhoField = forceSubM(0).rhoField();
vector position(0,0,0);
vector lift(0,0,0);
vector Us(0,0,0);
vector Ur(0,0,0);
scalar magUr(0);
scalar magVorticity(0);
scalar ds(0);
scalar dParcel(0);
scalar nuf(0);
scalar rho(0);
scalar voidfraction(1);
scalar Rep(0);
scalar Rew(0);
scalar Cl(0);
scalar Cl_star(0);
scalar J_star(0);
scalar Omega_eq(0);
scalar alphaStar(0);
scalar epsilon(0);
scalar omega_star(0);
vector vorticity(0,0,0);
volVectorField vorticity_ = fvc::curl(U_);
#include "resetVorticityInterpolator.H"
#include "resetUInterpolator.H"
#include "setupProbeModel.H"
for(int index = 0;index < particleCloud_.numberOfParticles(); index++)
{
//if(mask[index][0])
//{
lift = vector::zero;
label cellI = particleCloud_.cellIDs()[index][0];
if (cellI > -1) // particle Found
{
Us = particleCloud_.velocity(index);
if( forceSubM(0).interpolation() )
{
position = particleCloud_.position(index);
Ur = UInterpolator_().interpolate(position,cellI)
- Us;
vorticity = vorticityInterpolator_().interpolate(position,cellI);
}
else
{
Ur = U_[cellI]
- Us;
vorticity=vorticity_[cellI];
}
magUr = mag(Ur);
magVorticity = mag(vorticity);
if (magUr > 0 && magVorticity > 0)
{
ds = 2*particleCloud_.radius(index);
dParcel = ds;
forceSubM(0).scaleDia(ds,index); //caution: this fct will scale ds!
nuf = nufField[cellI];
rho = rhoField[cellI];
//Update any scalar or vector quantity
for (int iFSub=0;iFSub<nrForceSubModels();iFSub++)
forceSubM(iFSub).update( index,
cellI,
ds,
nuf,
rho,
forceSubM(0).verbose()
);
// calc dimensionless properties
Rep = ds*magUr/nuf;
Rew = magVorticity*ds*ds/nuf;
alphaStar = magVorticity*ds/magUr/2.0;
epsilon = sqrt(2.0*alphaStar /Rep );
omega_star=2.0*alphaStar;
//Basic model for the correction to the Saffman lift
//Based on McLaughlin (1991)
if(epsilon < 0.1)
{
J_star = -140 *epsilon*epsilon*epsilon*epsilon*epsilon
*log( 1./(epsilon*epsilon+SMALL) );
}
else if(epsilon > 20)
{
J_star = 1.0-0.287/(epsilon*epsilon+SMALL);
}
else
{
J_star = 0.3
*( 1.0
+tanh( 2.5 * log10(epsilon+0.191) )
)
*( 0.667
+tanh( 6.0 * (epsilon-0.32) )
);
}
Cl=J_star*4.11*epsilon; //multiply McLaughlin's correction to the basic Saffman model
//Second order terms given by Loth and Dorgan 2009
if(useSecondOrderTerms_)
{
Omega_eq = omega_star/2.0*(1.0-0.0075*Rew)*(1.0-0.062*sqrt(Rep)-0.001*Rep);
Cl_star=1.0-(0.675+0.15*(1.0+tanh(0.28*(omega_star/2.0-2.0))))*tanh(0.18*sqrt(Rep));
Cl += Omega_eq*Cl_star;
}
lift = 0.125*M_PI
*rho
*Cl
*magUr*Ur^vorticity/magVorticity
*ds*ds; //total force on all particles in parcel
forceSubM(0).scaleForce(lift,dParcel,index);
if (modelType_=="B")
{
voidfraction = particleCloud_.voidfraction(index);
lift /= voidfraction;
}
}
//**********************************
//SAMPLING AND VERBOSE OUTOUT
if( forceSubM(0).verbose() )
{
Pout << "index = " << index << endl;
Pout << "Us = " << Us << endl;
Pout << "Ur = " << Ur << endl;
Pout << "vorticity = " << vorticity << endl;
Pout << "dprim = " << ds << endl;
Pout << "rho = " << rho << endl;
Pout << "nuf = " << nuf << endl;
Pout << "Rep = " << Rep << endl;
Pout << "Rew = " << Rew << endl;
Pout << "alphaStar = " << alphaStar << endl;
Pout << "epsilon = " << epsilon << endl;
Pout << "J_star = " << J_star << endl;
Pout << "lift = " << lift << 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, lift); //first entry must the be the force
vValues.setSize(vValues.size()+1, Ur);
vValues.setSize(vValues.size()+1, vorticity);
sValues.setSize(sValues.size()+1, Rep);
sValues.setSize(sValues.size()+1, Rew);
sValues.setSize(sValues.size()+1, J_star);
particleCloud_.probeM().writeProbe(index, sValues, vValues);
}
// END OF SAMPLING AND VERBOSE OUTOUT
//**********************************
}
// write particle based data to global array
forceSubM(0).partToArray(index,lift,vector::zero);
//}
}
}
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);
}
}
