예제 #1
0
void Foam::MaxwellianThermal<CloudType>::correct
(
    typename CloudType::parcelType& p,
    const wallPolyPatch& wpp
)
{
    vector& U = p.U();

    scalar& Ei = p.Ei();

    label typeId = p.typeId();

    label wppIndex = wpp.index();

    label wppLocalFace = wpp.whichFace(p.face());

    vector nw = p.normal();
    nw /= mag(nw);

    // Normal velocity magnitude
    scalar U_dot_nw = U & nw;

    // Wall tangential velocity (flow direction)
    vector Ut = U - U_dot_nw*nw;

    CloudType& cloud(this->owner());

    Random& rndGen(cloud.rndGen());

    while (mag(Ut) < SMALL)
    {
        // If the incident velocity is parallel to the face normal, no
        // tangential direction can be chosen.  Add a perturbation to the
        // incoming velocity and recalculate.

        U = vector
        (
            U.x()*(0.8 + 0.2*rndGen.scalar01()),
            U.y()*(0.8 + 0.2*rndGen.scalar01()),
            U.z()*(0.8 + 0.2*rndGen.scalar01())
        );

        U_dot_nw = U & nw;

        Ut = U - U_dot_nw*nw;
    }

    // Wall tangential unit vector
    vector tw1 = Ut/mag(Ut);

    // Other tangential unit vector
    vector tw2 = nw^tw1;

    scalar T = cloud.boundaryT().boundaryField()[wppIndex][wppLocalFace];

    scalar mass = cloud.constProps(typeId).mass();

    scalar iDof = cloud.constProps(typeId).internalDegreesOfFreedom();

    U =
        sqrt(physicoChemical::k.value()*T/mass)
       *(
            rndGen.GaussNormal()*tw1
          + rndGen.GaussNormal()*tw2
          - sqrt(-2.0*log(max(1 - rndGen.scalar01(), VSMALL)))*nw
        );

    U += cloud.boundaryU().boundaryField()[wppIndex][wppLocalFace];

    Ei = cloud.equipartitionInternalEnergy(T, iDof);
}
예제 #2
0
void Foam::MixedDiffuseSpecular<CloudType>::correct
(
    typename CloudType::parcelType& p
)
{
    vector& U = p.U();

    scalar& Ei = p.Ei();

    label typeId = p.typeId();

    const label wppIndex = p.patch();

    const polyPatch& wpp = p.mesh().boundaryMesh()[wppIndex];

    label wppLocalFace = wpp.whichFace(p.face());

    const vector nw = p.normal();

    // Normal velocity magnitude
    scalar U_dot_nw = U & nw;

    CloudType& cloud(this->owner());

    Random& rndGen(cloud.rndGen());

    if (diffuseFraction_ > rndGen.scalar01())
    {
        // Diffuse reflection

        // Wall tangential velocity (flow direction)
        vector Ut = U - U_dot_nw*nw;

        while (mag(Ut) < small)
        {
            // If the incident velocity is parallel to the face normal, no
            // tangential direction can be chosen.  Add a perturbation to the
            // incoming velocity and recalculate.

            U = vector
            (
                U.x()*(0.8 + 0.2*rndGen.scalar01()),
                U.y()*(0.8 + 0.2*rndGen.scalar01()),
                U.z()*(0.8 + 0.2*rndGen.scalar01())
            );

            U_dot_nw = U & nw;

            Ut = U - U_dot_nw*nw;
        }

        // Wall tangential unit vector
        vector tw1 = Ut/mag(Ut);

        // Other tangential unit vector
        vector tw2 = nw^tw1;

        scalar T = cloud.boundaryT().boundaryField()[wppIndex][wppLocalFace];

        scalar mass = cloud.constProps(typeId).mass();

        direction iDof = cloud.constProps(typeId).internalDegreesOfFreedom();

        U =
            sqrt(physicoChemical::k.value()*T/mass)
           *(
                rndGen.scalarNormal()*tw1
              + rndGen.scalarNormal()*tw2
              - sqrt(-2.0*log(max(1 - rndGen.scalar01(), vSmall)))*nw
            );

        U += cloud.boundaryU().boundaryField()[wppIndex][wppLocalFace];

        Ei = cloud.equipartitionInternalEnergy(T, iDof);
    }
    else
    {
        // Specular reflection

        if (U_dot_nw > 0.0)
        {
            U -= 2.0*U_dot_nw*nw;
        }
    }

}