void Foam::PairSpringSliderDashpot<CloudType>::evaluatePair
(
    typename CloudType::parcelType& pA,
    typename CloudType::parcelType& pB
) const
{
    vector r_AB = (pA.position() - pB.position());

    scalar dAEff = pA.d();

    if (useEquivalentSize_)
    {
        dAEff *= cbrt(pA.nParticle()*volumeFactor_);
    }

    scalar dBEff = pB.d();

    if (useEquivalentSize_)
    {
        dBEff *= cbrt(pB.nParticle()*volumeFactor_);
    }

    scalar r_AB_mag = mag(r_AB);

    scalar normalOverlapMag = 0.5*(dAEff + dBEff) - r_AB_mag;

    if (normalOverlapMag > 0)
    {
        //Particles in collision

        vector rHat_AB = r_AB/(r_AB_mag + VSMALL);

        vector U_AB = pA.U() - pB.U();

        // Effective radius
        scalar R = 0.5*dAEff*dBEff/(dAEff + dBEff);

        // Effective mass
        scalar M = pA.mass()*pB.mass()/(pA.mass() + pB.mass());

        scalar kN = (4.0/3.0)*sqrt(R)*Estar_;

        scalar etaN = alpha_*sqrt(M*kN)*pow025(normalOverlapMag);

        // Normal force
        vector fN_AB =
            rHat_AB
           *(kN*pow(normalOverlapMag, b_) - etaN*(U_AB & rHat_AB));

        // Cohesion force
        if (cohesion_)
        {
            fN_AB +=
                -cohesionEnergyDensity_
                *overlapArea(dAEff/2.0, dBEff/2.0, r_AB_mag)
                *rHat_AB;
        }

        pA.f() += fN_AB;
        pB.f() += -fN_AB;

        vector USlip_AB =
            U_AB - (U_AB & rHat_AB)*rHat_AB
          + (pA.omega() ^ (dAEff/2*-rHat_AB))
          - (pB.omega() ^ (dBEff/2*rHat_AB));

        scalar deltaT = this->owner().mesh().time().deltaTValue();

        vector& tangentialOverlap_AB =
            pA.collisionRecords().matchPairRecord
            (
                pB.origProc(),
                pB.origId()
            ).collisionData();

        vector& tangentialOverlap_BA =
            pB.collisionRecords().matchPairRecord
            (
                pA.origProc(),
                pA.origId()
            ).collisionData();

        vector deltaTangentialOverlap_AB = USlip_AB*deltaT;

        tangentialOverlap_AB += deltaTangentialOverlap_AB;
        tangentialOverlap_BA += -deltaTangentialOverlap_AB;

        scalar tangentialOverlapMag = mag(tangentialOverlap_AB);

        if (tangentialOverlapMag > VSMALL)
        {
            scalar kT = 8.0*sqrt(R*normalOverlapMag)*Gstar_;

            scalar etaT = etaN;

            // Tangential force
            vector fT_AB;

            if (kT*tangentialOverlapMag > mu_*mag(fN_AB))
            {
                // Tangential force greater than sliding friction,
                // particle slips

                fT_AB = -mu_*mag(fN_AB)*USlip_AB/mag(USlip_AB);

                tangentialOverlap_AB = vector::zero;
                tangentialOverlap_BA = vector::zero;
            }
            else
            {
                fT_AB =
                    -kT*tangentialOverlapMag
                   *tangentialOverlap_AB/tangentialOverlapMag
                  - etaT*USlip_AB;
            }

            pA.f() += fT_AB;
            pB.f() += -fT_AB;

            pA.torque() += (dAEff/2*-rHat_AB) ^ fT_AB;
            pB.torque() += (dBEff/2*rHat_AB) ^ -fT_AB;
        }
    }
}
bool Foam::StandardWallInteraction<CloudType>::correct
(
    typename CloudType::parcelType& p,
    const polyPatch& pp,
    bool& keepParticle,
    const scalar trackFraction,
    const tetIndices& tetIs
)
{
    vector& U = p.U();

    bool& active = p.active();

    if (isA<wallPolyPatch>(pp))
    {
        switch (interactionType_)
        {
            case PatchInteractionModel<CloudType>::itEscape:
            {
                scalar dm = p.mass()*p.nParticle();

                keepParticle = false;
                active = false;
                U = vector::zero;
                nEscape_++;
                massEscape_ += dm;
                break;
            }
            case PatchInteractionModel<CloudType>::itStick:
            {
                keepParticle = true;
                active = false;
                U = vector::zero;
                nStick_++;
                break;
            }
            case PatchInteractionModel<CloudType>::itRebound:
            {
                keepParticle = true;
                active = true;

                vector nw;
                vector Up;

                this->owner().patchData(p, pp, trackFraction, tetIs, nw, Up);

                // Calculate motion relative to patch velocity
                U -= Up;

                scalar Un = U & nw;
                vector Ut = U - Un*nw;

                if (Un > 0)
                {
                    U -= (1.0 + e_)*Un*nw;
                }

                U -= mu_*Ut;

                // Return velocity to global space
                U += Up;

                break;
            }
            default:
            {
                FatalErrorIn
                (
                    "bool StandardWallInteraction<CloudType>::correct"
                    "("
                        "typename CloudType::parcelType&, "
                        "const polyPatch&, "
                        "bool& keepParticle, "
                        "const scalar, "
                        "const tetIndices&"
                    ") const"
                )   << "Unknown interaction type "
                    << this->interactionTypeToWord(interactionType_)
                    << "(" << interactionType_ << ")" << endl
                    << abort(FatalError);
            }
        }

        return true;
    }

    return false;
}
void Foam::WallLocalSpringSliderDashpot<CloudType>::evaluateWall
(
    typename CloudType::parcelType& p,
    const point& site,
    const WallSiteData<vector>& data,
    scalar pREff
) const
{
    // wall patch index
    label wPI = patchMap_[data.patchIndex()];

    // data for this patch
    scalar Estar = Estar_[wPI];
    scalar Gstar = Gstar_[wPI];
    scalar alpha = alpha_[wPI];
    scalar b = b_[wPI];
    scalar mu = mu_[wPI];

    vector r_PW = p.position() - site;

    vector U_PW = p.U() - data.wallData();

    scalar normalOverlapMag = max(pREff - mag(r_PW), 0.0);

    vector rHat_PW = r_PW/(mag(r_PW) + VSMALL);

    scalar kN = (4.0/3.0)*sqrt(pREff)*Estar;

    scalar etaN = alpha*sqrt(p.mass()*kN)*pow025(normalOverlapMag);

    vector fN_PW =
        rHat_PW
       *(kN*pow(normalOverlapMag, b) - etaN*(U_PW & rHat_PW));

    p.f() += fN_PW;

    vector USlip_PW =
        U_PW - (U_PW & rHat_PW)*rHat_PW
      + (p.omega() ^ (pREff*-rHat_PW));

    scalar deltaT = this->owner().mesh().time().deltaTValue();

    vector& tangentialOverlap_PW =
        p.collisionRecords().matchWallRecord(-r_PW, pREff).collisionData();

    tangentialOverlap_PW += USlip_PW*deltaT;

    scalar tangentialOverlapMag = mag(tangentialOverlap_PW);

    if (tangentialOverlapMag > VSMALL)
    {
        scalar kT = 8.0*sqrt(pREff*normalOverlapMag)*Gstar;

        scalar etaT = etaN;

        // Tangential force
        vector fT_PW;

        if (kT*tangentialOverlapMag > mu*mag(fN_PW))
        {
            // Tangential force greater than sliding friction,
            // particle slips

            fT_PW = -mu*mag(fN_PW)*USlip_PW/mag(USlip_PW);

            tangentialOverlap_PW = vector::zero;
        }
        else
        {
            fT_PW =
                -kT*tangentialOverlapMag
               *tangentialOverlap_PW/tangentialOverlapMag
              - etaT*USlip_PW;
        }

        p.f() += fT_PW;

        p.torque() += (pREff*-rHat_PW) ^ fT_PW;
    }
}
Ejemplo n.º 4
0
bool Foam::LocalInteraction<CloudType>::correct
(
    typename CloudType::parcelType& p,
    const polyPatch& pp,
    bool& keepParticle,
    const scalar trackFraction,
    const tetIndices& tetIs
)
{
    label patchI = patchData_.applyToPatch(pp.index());

    if (patchI >= 0)
    {
        vector& U = p.U();
        bool& active = p.active();

        typename PatchInteractionModel<CloudType>::interactionType it =
            this->wordToInteractionType
            (
                patchData_[patchI].interactionTypeName()
            );

        switch (it)
        {
            case PatchInteractionModel<CloudType>::itEscape:
            {
                scalar dm = p.mass()*p.nParticle();

                keepParticle = false;
                active = false;
                U = vector::zero;
                nEscape_[patchI]++;
                massEscape_[patchI] += dm;
                if (writeFields_)
                {
                    label pI = pp.index();
                    label fI = pp.whichFace(p.face());
                    massEscape().boundaryField()[pI][fI] += dm;
                }
                break;
            }
            case PatchInteractionModel<CloudType>::itStick:
            {
                scalar dm = p.mass()*p.nParticle();

                keepParticle = true;
                active = false;
                U = vector::zero;
                nStick_[patchI]++;
                massStick_[patchI] += dm;
                if (writeFields_)
                {
                    label pI = pp.index();
                    label fI = pp.whichFace(p.face());
                    massStick().boundaryField()[pI][fI] += dm;
                }
                break;
            }
            case PatchInteractionModel<CloudType>::itRebound:
            {
                keepParticle = true;
                active = true;

                vector nw;
                vector Up;

                this->owner().patchData(p, pp, trackFraction, tetIs, nw, Up);

                // Calculate motion relative to patch velocity
                U -= Up;

                scalar Un = U & nw;
                vector Ut = U - Un*nw;

                if (Un > 0)
                {
                    U -= (1.0 + patchData_[patchI].e())*Un*nw;
                }

                U -= patchData_[patchI].mu()*Ut;

                // Return velocity to global space
                U += Up;

                break;
            }
            default:
            {
                FatalErrorIn
                (
                    "bool LocalInteraction<CloudType>::correct"
                    "("
                        "typename CloudType::parcelType&, "
                        "const polyPatch&, "
                        "bool&, "
                        "const scalar, "
                        "const tetIndices&"
                    ") const"
                )   << "Unknown interaction type "
                    << patchData_[patchI].interactionTypeName()
                    << "(" << it << ") for patch "
                    << patchData_[patchI].patchName()
                    << ". Valid selections are:" << this->interactionTypeNames_
                    << endl << abort(FatalError);
            }
        }

        return true;
    }

    return false;
}