Foam::forceSuSp Foam::PlessisMasliyahDragForce<CloudType>::calcCoupled
(
const typename CloudType::parcelType& p,
const scalar dt,
const scalar mass,
const scalar Re,
const scalar muc
) const
{
scalar alphac(alphac_[p.cell()]);
scalar cbrtAlphap(pow(1.0 - alphac, 1.0/3.0));
scalar A =
26.8*pow3(alphac)
/(
sqr(cbrtAlphap)
*(1.0 - cbrtAlphap)
*sqr(1.0 - sqr(cbrtAlphap))
+ SMALL
);
scalar B =
sqr(alphac)
/sqr(1.0 - sqr(cbrtAlphap));
return forceSuSp
(
vector::zero,
(mass/p.rho())
*(A*(1.0 - alphac) + B*Re)*muc/(alphac*sqr(p.d()))
);
}
Foam::forceSuSp Foam::DPMDragModels::ErgunWenYu<CloudType>::calcCoupled
(
const typename CloudType::parcelType& p,
const scalar dt,
const scalar mass,
const scalar Re,
const scalar muc
) const
{
scalar alphac(alphac_[p.cell()]);
if (alphac < 0.8)
{
return forceSuSp
(
vector::zero,
(mass/p.rho())
*((150.0*(1.0 - alphac) + 1.75*Re)*muc/(alphac*sqr(p.d())))
);
}
else
{
return forceSuSp
(
vector::zero,
(mass/p.rho())
*0.75*CdRe(alphac*Re)*muc*pow(alphac, -2.65)/sqr(p.d())
);
}
}
Foam::vector Foam::DampingModels::Relaxation<CloudType>::velocityCorrection
(
typename CloudType::parcelType& p,
const scalar deltaT
) const
{
const tetIndices
tetIs(p.cell(), p.tetFace(), p.tetPt(), this->owner().mesh());
const scalar x =
deltaT*oneByTimeScaleAverage_->interpolate(p.position(), tetIs);
const vector u = uAverage_->interpolate(p.position(), tetIs);
return (u - p.U())*x/(x + 2.0);
}
Foam::forceSuSp Foam::BrownianMotionForce<CloudType>::calcCoupled
(
const typename CloudType::parcelType& p,
const scalar dt,
const scalar mass,
const scalar Re,
const scalar muc
) const
{
forceSuSp value(vector::zero, 0.0);
const scalar dp = p.d();
const scalar Tc = p.Tc();
const scalar eta = rndGen_.sample01<scalar>();
const scalar alpha = 2.0*lambda_/dp;
const scalar cc = 1.0 + alpha*(1.257 + 0.4*exp(-1.1/alpha));
const scalar sigma = physicoChemical::sigma.value();
scalar f = 0.0;
if (turbulence_)
{
const label cellI = p.cell();
const volScalarField& k = *kPtr_;
const scalar kc = k[cellI];
const scalar Dp = sigma*Tc*cc/(3*mathematical::pi*muc*dp);
f = eta/mass*sqrt(2.0*sqr(kc)*sqr(Tc)/(Dp*dt));
}
else
{
const scalar rhoRatio = p.rho()/p.rhoc();
const scalar s0 =
216*muc*sigma*Tc/(sqr(mathematical::pi)*pow5(dp)*(rhoRatio)*cc);
f = eta*sqrt(mathematical::pi*s0/dt);
}
const scalar sqrt2 = sqrt(2.0);
for (label i = 0; i < 3; i++)
{
const scalar x = rndGen_.sample01<scalar>();
const scalar eta = sqrt2*erfInv(2*x - 1.0);
value.Su()[i] = mass*f*eta;
}
return value;
}
Foam::forceSuSp Foam::WenYuDragForce<CloudType>::calcCoupled
(
const typename CloudType::parcelType& p,
const scalar dt,
const scalar mass,
const scalar Re,
const scalar muc
) const
{
scalar alphac(alphac_[p.cell()]);
return forceSuSp
(
vector::zero,
(mass/p.rho())
*0.75*CdRe(alphac*Re)*muc*pow(alphac, -2.65)/(alphac*sqr(p.d()))
);
}
Foam::forceSuSp Foam::BrownianMotionForce<CloudType>::calcCoupled
(
const typename CloudType::parcelType& p,
const typename CloudType::parcelType::trackingData& td,
const scalar dt,
const scalar mass,
const scalar Re,
const scalar muc
) const
{
forceSuSp value(Zero, 0.0);
const scalar dp = p.d();
const scalar Tc = td.Tc();
const scalar alpha = 2.0*lambda_/dp;
const scalar cc = 1.0 + alpha*(1.257 + 0.4*exp(-1.1/alpha));
// Boltzmann constant
const scalar kb = physicoChemical::k.value();
scalar f = 0;
if (turbulence_)
{
const label celli = p.cell();
const volScalarField& k = *kPtr_;
const scalar kc = k[celli];
const scalar Dp = kb*Tc*cc/(3*mathematical::pi*muc*dp);
f = sqrt(2.0*sqr(kc)*sqr(Tc)/(Dp*dt));
}
else
{
const scalar s0 =
216*muc*kb*Tc/(sqr(mathematical::pi)*pow5(dp)*sqr(p.rho())*cc);
f = mass*sqrt(mathematical::pi*s0/dt);
}
// To generate a cubic distribution (3 independent directions) :
// const scalar sqrt2 = sqrt(2.0);
// for (direction dir = 0; dir < vector::nComponents; dir++)
// {
// const scalar x = rndGen_.sample01<scalar>();
// const scalar eta = sqrt2*erfInv(2*x - 1.0);
// value.Su()[dir] = f*eta;
// }
// To generate a spherical distribution:
Random& rnd = this->owner().rndGen();
const scalar theta = rnd.scalar01()*twoPi;
const scalar u = 2*rnd.scalar01() - 1;
const scalar a = sqrt(1 - sqr(u));
const vector dir(a*cos(theta), a*sin(theta), u);
value.Su() = f*mag(rnd.scalarNormal())*dir;
return value;
}
