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);
}
void Foam::PatchInteractionModel<CloudType>::patchData
(
typename CloudType::parcelType& p,
const polyPatch& pp,
const scalar trackFraction,
const tetIndices& tetIs,
vector& nw,
vector& Up
) const
{
const fvMesh& mesh = this->owner().mesh();
const volVectorField& Ufield =
mesh.objectRegistry::lookupObject<volVectorField>(UName_);
label patchI = pp.index();
label patchFaceI = pp.whichFace(p.face());
vector n = tetIs.faceTri(mesh).normal();
n /= mag(n);
vector U = Ufield.boundaryField()[patchI][patchFaceI];
// Unless the face is rotating, the required normal is n;
nw = n;
if (!mesh.moving())
{
// Only wall patches may have a non-zero wall velocity from
// the velocity field when the mesh is not moving.
if (isA<wallPolyPatch>(pp))
{
Up = U;
}
else
{
Up = vector::zero;
}
}
else
{
vector U00 = Ufield.oldTime().boundaryField()[patchI][patchFaceI];
vector n00 = tetIs.oldFaceTri(mesh).normal();
// Difference in normal over timestep
vector dn = vector::zero;
if (mag(n00) > SMALL)
{
// If the old normal is zero (for example in layer
// addition) then use the current normal, meaning that the
// motion can only be translational, and dn remains zero,
// otherwise, calculate dn:
n00 /= mag(n00);
dn = n - n00;
}
// Total fraction thought the timestep of the motion,
// including stepFraction before the current tracking step
// and the current trackFraction
// i.e.
// let s = stepFraction, t = trackFraction
// Motion of x in time:
// |-----------------|---------|---------|
// x00 x0 xi x
//
// where xi is the correct value of x at the required
// tracking instant.
//
// x0 = x00 + s*(x - x00) = s*x + (1 - s)*x00
//
// i.e. the motion covered by previous tracking portions
// within this timestep, and
//
// xi = x0 + t*(x - x0)
// = t*x + (1 - t)*x0
// = t*x + (1 - t)*(s*x + (1 - s)*x00)
// = (s + t - s*t)*x + (1 - (s + t - s*t))*x00
//
// let m = (s + t - s*t)
//
// xi = m*x + (1 - m)*x00 = x00 + m*(x - x00);
//
// In the same form as before.
scalar m =
p.stepFraction()
+ trackFraction
- (p.stepFraction()*trackFraction);
// When the mesh is moving, the velocity field on wall patches
// will contain the velocity associated with the motion of the
// mesh, in which case it is interpolated in time using m.
// For other patches the face velocity will need to be
// reconstructed from the face centre motion.
const vector& Cf = mesh.faceCentres()[p.face()];
vector Cf00 = mesh.faces()[p.face()].centre(mesh.oldPoints());
if (isA<wallPolyPatch>(pp))
{
Up = U00 + m*(U - U00);
}
else
{
Up = (Cf - Cf00)/this->owner().time().deltaTValue();
}
if (mag(dn) > SMALL)
{
// Rotational motion, nw requires interpolation and a
// rotational velocity around face centre correction to Up
// is required.
nw = n00 + m*dn;
// Cf at tracking instant
vector Cfi = Cf00 + m*(Cf - Cf00);
// Normal vector cross product
vector omega = (n00 ^ n);
scalar magOmega = mag(omega);
// magOmega = sin(angle between unit normals)
// Normalise omega vector by magOmega, then multiply by
// angle/dt to give the correct angular velocity vector.
omega *=
Foam::asin(magOmega)
/(magOmega*this->owner().time().deltaTValue());
// Project position onto face and calculate this position
// relative to the face centre.
vector facePos =
p.position()
- ((p.position() - Cfi) & nw)*nw
- Cfi;
Up += (omega ^ facePos);
}
// No further action is required if the motion is
// translational only, nw and Up have already been set.
}
}
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;
}
}
}
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;
}
