BrownianCollisions.C

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#include "BrownianCollisions.H"
#include "addToRunTimeSelectionTable.H"
#include "fundamentalConstants.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
namespace diameterModels
{
namespace coalescenceModels
{
    defineTypeNameAndDebug(BrownianCollisions, 0);
    addToRunTimeSelectionTable
    (
        coalescenceModel,
        BrownianCollisions,
        dictionary
    );
}
}
}
 
using Foam::constant::physicoChemical::k;
using Foam::constant::mathematical::pi;
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::diameterModels::coalescenceModels::BrownianCollisions::
BrownianCollisions
(
    const populationBalanceModel& popBal,
    const dictionary& dict
)
:
    coalescenceModel(popBal, dict),
    A1_(dict.lookupOrDefault<scalar>("A1", 2.514)),
    A2_(dict.lookupOrDefault<scalar>("A2", 0.8)),
    A3_(dict.lookupOrDefault<scalar>("A3", 0.55)),
    sigma_("sigma", dimLength, dict),
    lambda_
    (
        IOobject
        (
            "lambda",
            popBal_.time().name(),
            popBal_.mesh()
        ),
        popBal_.mesh(),
        dimensionedScalar
        (
            "lambda",
            dimLength,
            Zero
        )
    )
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
void Foam::diameterModels::coalescenceModels::BrownianCollisions::precompute()
{
    const volScalarField::Internal& p =
        popBal_.continuousPhase().fluidThermo().p();
 
    const volScalarField::Internal& Tc = popBal_.continuousPhase().thermo().T();
 
    lambda_ = k*Tc/(sqrt(2.0)*pi*p*sqr(sigma_));
}
 
 
void Foam::diameterModels::coalescenceModels::BrownianCollisions::
addToCoalescenceRate
(
    volScalarField::Internal& coalescenceRate,
    const label i,
    const label j
)
{
    const sizeGroup& fi = popBal_.sizeGroups()[i];
    const sizeGroup& fj = popBal_.sizeGroups()[j];
 
    tmp<volScalarField> tdi = fi.d();
    const volScalarField::Internal& di = tdi();
    tmp<volScalarField> tdj = fj.d();
    const volScalarField::Internal& dj = tdj();
 
    const volScalarField::Internal& Tc = popBal_.continuousPhase().thermo().T();
 
    tmp<volScalarField> tmuc(popBal_.continuousPhase().fluidThermo().mu());
    const volScalarField::Internal& muc = tmuc();
 
    const volScalarField::Internal Cci
    (
        1 + lambda_/di*(A1_ + A2_*exp(-A3_*di/lambda_))
    );
 
    const volScalarField::Internal Ccj
    (
        1 + lambda_/dj*(A1_ + A2_*exp(-A3_*dj/lambda_))
    );
 
    coalescenceRate += 8*k*Tc/(3*muc)*(di + dj)*(Cci/di + Ccj/dj);
}
 
 
// ************************************************************************* //