void SchillerNaumannDrag::setForce() const
{
// get viscosity field
#ifdef comp
const volScalarField nufField = particleCloud_.turbulence().mu() / rho_;
#else
const volScalarField& nufField = particleCloud_.turbulence().nu();
#endif
#include "setupProbeModel.H"
for(int index = 0;index < particleCloud_.numberOfParticles(); index++)
{
//if(mask[index][0])
//{
vector drag(0,0,0);
vector Uturb(0,0,0);
vector position(0,0,0);
label cellI = particleCloud_.cellIDs()[index][0];
if (cellI > -1) // particle Found
{
//NP note: one could add pointInterpolated values instead of cell centered
vector Us = particleCloud_.velocity(index);
vector Ur = U_[cellI]-Us;
position = particleCloud_.position(index);
//accounting for turbulent dispersion
if(particleCloud_.dispersionM().isActive())
{
Uturb=particleCloud_.fluidTurbVel(index);
Ur=(U_[cellI]+Uturb)-Us;
}
scalar ds = 2*particleCloud_.radius(index);
scalar nuf = nufField[cellI];
scalar rho = rho_[cellI];
scalar voidfraction = particleCloud_.voidfraction(index);
scalar magUr = mag(Ur);
scalar Rep = 0;
scalar Cd = 0;
if (magUr > 0)
{
// calc particle Re Nr
Rep = ds*magUr/nuf;
// calc fluid drag Coeff
Cd = max(0.44,24.0/Rep*(1.0+0.15*pow(Rep,0.687)));
// calc particle's drag
drag = 0.125*Cd*rho*M_PI*ds*ds*magUr*Ur;
if (modelType_=="B")
drag /= voidfraction;
}
if(verbose_ && index >=0 && index <1)
{
Pout << " "<< endl;
Pout << "SchillerNaumannDrag drag force verbose: " << endl;
Info << "index = " << index << endl;
Pout << "position = " << position << endl;
Pout << "Ufluid = " << U_[cellI] << endl;
Pout << "Uturb = " << Uturb << endl;
Pout << "Us = " << Us << endl;
Info << "Ur = " << Ur << endl;
Info << "ds = " << ds << endl;
Info << "rho = " << rho << endl;
Info << "nuf = " << nuf << endl;
Info << "voidfraction = " << voidfraction << endl;
Info << "Rep = " << Rep << endl;
Info << "Cd = " << Cd << endl;
Info << "drag = " << drag << 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(Cd);
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];
for(int j=0;j<3;j++) DEMForces()[index][j] += drag[j];
//}
}
}
bool Foam::parcel::move(spray& sDB)
{
const polyMesh& mesh = cloud().pMesh();
const polyBoundaryMesh& pbMesh = mesh.boundaryMesh();
const liquidMixture& fuels = sDB.fuels();
scalar deltaT = sDB.runTime().deltaT().value();
label Nf = fuels.components().size();
label Ns = sDB.composition().Y().size();
// Calculate the interpolated gas properties at the position of the parcel
vector Up = sDB.UInterpolator().interpolate(position(), cell())
+ Uturb();
scalar rhog = sDB.rhoInterpolator().interpolate(position(), cell());
scalar pg = sDB.pInterpolator().interpolate(position(), cell());
scalar Tg = sDB.TInterpolator().interpolate(position(), cell());
scalarField Yfg(Nf, 0.0);
scalar cpMixture = 0.0;
for(label i=0; i<Ns; i++)
{
const volScalarField& Yi = sDB.composition().Y()[i];
if (sDB.isLiquidFuel()[i])
{
label j = sDB.gasToLiquidIndex()[i];
scalar Yicelli = Yi[cell()];
Yfg[j] = Yicelli;
}
cpMixture += Yi[cell()]*sDB.gasProperties()[i].Cp(Tg);
}
// Correct the gaseous temperature for evaporated fuel
scalar cellV = sDB.mesh().V()[cell()];
scalar cellMass = rhog*cellV;
Tg += sDB.shs()[cell()]/(cpMixture*cellMass);
// Changed cut-off temperature for evaporation. HJ, 27/Apr/2011
Tg = max(273, Tg);
scalar tauMomentum = GREAT;
scalar tauHeatTransfer = GREAT;
scalarField tauEvaporation(Nf, GREAT);
scalarField tauBoiling(Nf, GREAT);
bool keepParcel = true;
setRelaxationTimes
(
cell(),
tauMomentum,
tauEvaporation,
tauHeatTransfer,
tauBoiling,
sDB,
rhog,
Up,
Tg,
pg,
Yfg,
m()*fuels.Y(X()),
deltaT
);
// set the end-time for the track
scalar tEnd = (1.0 - stepFraction())*deltaT;
// Set the maximum time step for this parcel
// FPK changes: avoid temperature-out-of-range errors
// in spray tracking. HJ, 13/Oct/2007
// tauEvaporation no longer multiplied by 1e20,
// to account for the evaporation timescale
// FPK, 13/Oct/2007
scalar dtMax = min
(
tEnd,
min
(
tauMomentum,
min
(
mag(min(tauEvaporation)),
min
(
mag(tauHeatTransfer),
mag(min(tauBoiling))
)
)
)
)/sDB.subCycles();
// prevent the number of subcycles from being too many
// (10 000 seems high enough)
dtMax = max(dtMax, 1.0e-4*tEnd);
bool switchProcessor = false;
vector planeNormal = vector::zero;
if (sDB.twoD())
{
planeNormal = n() ^ sDB.axisOfSymmetry();
planeNormal /= mag(planeNormal);
}
// move the parcel until there is no 'timeLeft'
while (keepParcel && tEnd > SMALL && !switchProcessor)
{
// set the lagrangian time-step
scalar dt = min(dtMax, tEnd);
// remember which cell the parcel is in
// since this will change if a face is hit
label celli = cell();
scalar p = sDB.p()[celli];
// track parcel to face, or end of trajectory
if (keepParcel)
{
// Track and adjust the time step if the trajectory
// is not completed
dt *= trackToFace(position() + dt*U_, sDB);
// Decrement the end-time acording to how much time the track took
tEnd -= dt;
// Set the current time-step fraction.
stepFraction() = 1.0 - tEnd/deltaT;
if (onBoundary()) // hit face
{
# include "boundaryTreatment.H"
}
}
if (keepParcel && sDB.twoD())
{
scalar z = position() & sDB.axisOfSymmetry();
vector r = position() - z*sDB.axisOfSymmetry();
if (mag(r) > SMALL)
{
correctNormal(sDB.axisOfSymmetry());
}
}
// **** calculate the lagrangian source terms ****
// First we get the 'old' properties.
// and then 'update' them to get the 'new'
// properties.
// The difference is then added to the source terms.
scalar oRho = fuels.rho(p, T(), X());
scalarField oMass(Nf, 0.0);
scalar oHg = 0.0;
scalar oTotMass = m();
scalarField oYf(fuels.Y(X()));
forAll(oMass, i)
{
oMass[i] = m()*oYf[i];
label j = sDB.liquidToGasIndex()[i];
oHg += oYf[i]*sDB.gasProperties()[j].Hs(T());
}
vector oMom = m()*U();
scalar oHv = fuels.hl(p, T(), X());
scalar oH = oHg - oHv;
scalar oPE = (p - fuels.pv(p, T(), X()))/oRho;
// update the parcel properties (U, T, D)
updateParcelProperties
(
dt,
sDB,
celli,
face()
);
scalar nRho = fuels.rho(p, T(), X());
scalar nHg = 0.0;
scalarField nMass(Nf, 0.0);
scalarField nYf(fuels.Y(X()));
forAll(nMass, i)
{
nMass[i] = m()*nYf[i];
label j = sDB.liquidToGasIndex()[i];
nHg += nYf[i]*sDB.gasProperties()[j].Hs(T());
}
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
}
