Foam::tmp<Foam::volScalarField> Foam::SyamlalOBrien::K
(
const volScalarField& Ur
) const
{
volScalarField beta(max(scalar(1) - alpha_, scalar(1.0e-6)));
volScalarField A(pow(beta, 4.14));
volScalarField B
(
neg(beta - 0.85)*(0.8*pow(beta, 1.28))
+ pos(beta - 0.85)*(pow(beta, 2.65))
);
volScalarField Re(max(Ur*phasea_.d()/phaseb_.nu(), scalar(1.0e-3)));
volScalarField Vr
(
0.5*
(
A - 0.06*Re + sqrt(sqr(0.06*Re) + 0.12*Re*(2.0*B - A) + sqr(A))
)
);
volScalarField Cds(sqr(0.63 + 4.8*sqrt(Vr/Re)));
return 0.75*Cds*phaseb_.rho()*Ur/(phasea_.d()*sqr(Vr));
}
Foam::tmp<Foam::volScalarField> Foam::dragModels::SyamlalOBrien::CdRe() const
{
volScalarField alpha2
(
max(scalar(1) - pair_.dispersed(), pair_.continuous().residualAlpha())
);
volScalarField A(pow(alpha2, 4.14));
volScalarField B
(
neg(alpha2 - 0.85)*(0.8*pow(alpha2, 1.28))
+ pos0(alpha2 - 0.85)*(pow(alpha2, 2.65))
);
volScalarField Re(pair_.Re());
volScalarField Vr
(
0.5
*(
A - 0.06*Re + sqrt(sqr(0.06*Re) + 0.12*Re*(2.0*B - A) + sqr(A))
)
);
volScalarField CdsRe(sqr(0.63*sqrt(Re) + 4.8*sqrt(Vr)));
return
CdsRe
*max(pair_.continuous(), pair_.continuous().residualAlpha())
/sqr(Vr);
}
Foam::tmp<Foam::volScalarField> Foam::dragModels::SyamlalOBrien::K
(
const volScalarField& Ur
) const
{
volScalarField alpha2(max(phase2_, scalar(1.0e-6)));
volScalarField A(pow(alpha2, 4.14));
volScalarField B
(
neg(alpha2 - 0.85)*(0.8*pow(alpha2, 1.28))
+ pos(alpha2 - 0.85)*(pow(alpha2, 2.65))
);
volScalarField Re(max(Ur*phase1_.d()/phase2_.nu(), scalar(1.0e-3)));
volScalarField Vr
(
0.5*
(
A - 0.06*Re + sqrt(sqr(0.06*Re) + 0.12*Re*(2.0*B - A) + sqr(A))
)
);
volScalarField Cds(sqr(0.63 + 4.8*sqrt(Vr/Re)));
return 0.75*Cds*phase2_.rho()*Ur/(phase1_.d()*sqr(Vr));
}
Real Generalized_HullWhite::A(Time t, Time T) const {
DiscountFactor discount1 = termStructure()->discount(t);
DiscountFactor discount2 = termStructure()->discount(T);
Rate forward = termStructure()->forwardRate(t, t, Continuous, NoFrequency);
Real temp = B(t,T);
Real value = B(t,T)*forward - 0.5*temp*temp*Vr(0, t);
return std::exp(value)*discount2/discount1;
}
Real Generalized_HullWhite::Vp(Time t, Time Tf, Time Tp) const {
return Vr(t, Tf) * B(Tf, Tp) * B(Tf, Tp);
}
Real Generalized_HullWhite::stdDeviation(Time s, Time t, Rate x) {
return std::sqrt( Vr(s, t) );
}
