TAB.C

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    Copyright (C) 2011-2015 OpenFOAM Foundation
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License
    This file is part of OpenFOAM.
 
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#include "TAB.H"
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
template<class CloudType>
Foam::TAB<CloudType>::TAB
(
    const dictionary& dict,
    CloudType& owner
)
:
    BreakupModel<CloudType>(dict, owner, typeName, true),
    SMDCalcMethod_(this->coeffDict().lookup("SMDCalculationMethod"))
{
    // calculate the inverse function of the Rossin-Rammler Distribution
    const scalar xx0 = 12.0;
    const scalar rrd100 =
        1.0/(1.0 - exp(-xx0)*(1.0 + xx0 + sqr(xx0)/2.0 + pow3(xx0)/6.0));
 
    forAll(rrd_, n)
    {
        scalar xx = 0.12*(n + 1);
        rrd_[n] =
            (1.0 - exp(-xx)*(1.0 + xx + sqr(xx)/2.0 + pow3(xx)/6.0))*rrd100;
    }
 
    if (SMDCalcMethod_ == "method1")
    {
        SMDMethod_ = method1;
    }
    else if (SMDCalcMethod_ == "method2")
    {
        SMDMethod_ = method2;
    }
    else
    {
        SMDMethod_ = method2;
        WarningInFunction
            << "Unknown SMDCalculationMethod. Valid options are "
            << "(method1 | method2). Using method2" << endl;
    }
}
 
 
template<class CloudType>
Foam::TAB<CloudType>::TAB(const TAB<CloudType>& bum)
:
    BreakupModel<CloudType>(bum),
    SMDCalcMethod_(bum.SMDCalcMethod_)
{}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
template<class CloudType>
Foam::TAB<CloudType>::~TAB()
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
template<class CloudType>
bool Foam::TAB<CloudType>::update
(
    const scalar dt,
    const vector& g,
    scalar& d,
    scalar& tc,
    scalar& ms,
    scalar& nParticle,
    scalar& KHindex,
    scalar& y,
    scalar& yDot,
    const scalar d0,
    const scalar rho,
    const scalar mu,
    const scalar sigma,
    const vector& U,
    const scalar rhoc,
    const scalar muc,
    const vector& Urel,
    const scalar Urmag,
    const scalar tMom,
    scalar& dChild,
    scalar& massChild
)
{
    Random& rndGen = this->owner().rndGen();
 
    scalar r = 0.5*d;
    scalar r2 = r*r;
    scalar r3 = r*r2;
 
    scalar semiMass = nParticle*pow3(d);
 
    // inverse of characteristic viscous damping time
    scalar rtd = 0.5*this->TABCmu_*mu/(rho*r2);
 
    // oscillation frequency (squared)
    scalar omega2 = this->TABComega_*sigma/(rho*r3) - rtd*rtd;
 
    if (omega2 > 0)
    {
        scalar omega = sqrt(omega2);
        scalar We = rhoc*sqr(Urmag)*r/sigma;
        scalar Wetmp = We/this->TABtwoWeCrit_;
 
        scalar y1 = y - Wetmp;
        scalar y2 = yDot/omega;
 
        scalar a = sqrt(y1*y1 + y2*y2);
 
        // scotty we may have break-up
        if (a+Wetmp > 1.0)
        {
            scalar phic = y1/a;
 
            // constrain phic within -1 to 1
            phic = max(min(phic, 1), -1);
 
            scalar phit = acos(phic);
            scalar phi = phit;
            scalar quad = -y2/a;
            if (quad < 0)
            {
                phi = constant::mathematical::twoPi - phit;
            }
 
            scalar tb = 0;
 
            if (mag(y) < 1.0)
            {
                scalar coste = 1.0;
                if ((Wetmp - a < -1) && (yDot < 0))
                {
                    coste = -1.0;
                }
 
                scalar theta = acos((coste-Wetmp)/a);
 
                if (theta < phi)
                {
                    if (constant::mathematical::twoPi - theta >= phi)
                    {
                        theta = -theta;
                    }
                    theta += constant::mathematical::twoPi;
                }
                tb = (theta-phi)/omega;
 
                // breakup occurs
                if (dt > tb)
                {
                    y = 1.0;
                    yDot = -a*omega*sin(omega*tb + phi);
                }
 
            }
 
            // update droplet size
            if (dt > tb)
            {
                scalar rs =
                    r/(1.0 + (4.0/3.0)*sqr(y) + rho*r3/(8*sigma)*sqr(yDot));
 
                label n = 0;
                scalar rNew = 0.0;
                switch (SMDMethod_)
                {
                    case method1:
                    {
                        #include "TABSMDCalcMethod1.H"
                        break;
                    }
                    case method2:
                    {
                        #include "TABSMDCalcMethod2.H"
                        break;
                    }
                }
 
                if (rNew < r)
                {
                    d = 2*rNew;
                    y = 0;
                    yDot = 0;
                }
            }
        }
    }
    else
    {
        // reset droplet distortion parameters
        y = 0;
        yDot = 0;
    }
 
    // update the nParticle count to conserve mass
    nParticle = semiMass/pow3(d);
 
    // Do not add child parcel
    return false;
}
 
 
// ************************************************************************* //