From 09188eb8c62278b55d94bdefffa6c80c7eba7824 Mon Sep 17 00:00:00 2001
From: graham <g.macpherson@opencfd.co.uk>
Date: Tue, 18 May 2010 15:54:31 +0100
Subject: [PATCH] ENH: Adding volumeFraction to allow PairCollision models to
take account of nParticles to expand the effective parcel size for collision.
---
.../PairCollision/PairCollision.C | 2 +-
.../PairModel/PairModel/PairModel.H | 2 +-
.../PairSpringSliderDashpot.C | 25 ++++++++-----
.../PairSpringSliderDashpot.H | 24 +++++++++++++
.../WallModel/WallModel/WallModel.H | 5 ++-
.../WallSpringSliderDashpot.C | 36 +++++++++++++------
.../WallSpringSliderDashpot.H | 28 +++++++++++++++
.../InjectionModel/InjectionModel.C | 10 +++---
.../InjectionModel/InjectionModel.H | 4 +--
9 files changed, 107 insertions(+), 29 deletions(-)
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
index 27e8886cdd0..e1e1587c95d 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
@@ -213,7 +213,7 @@ void Foam::PairCollision<CloudType>::wallInteraction()
const point& pos = p.position();
- scalar r = p.d()/2;
+ scalar r = wallModel_->pREff(p);
// real wallFace interactions
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairModel/PairModel.H b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairModel/PairModel.H
index 1b6d1e56be4..b5b36fdb68b 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairModel/PairModel.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairModel/PairModel.H
@@ -54,7 +54,7 @@ class PairModel
{
// Private data
- //- The cloud dictionary
+ //- The CollisionModel dictionary
const dictionary& dict_;
//- Reference to the owner cloud class
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.C b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.C
index 752120d0bef..6c10eff509f 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.C
@@ -45,13 +45,15 @@ void Foam::PairSpringSliderDashpot<CloudType>::findMinMaxProperties
// Finding minimum diameter to avoid excessive arithmetic
- RMin = min(p.d(), RMin);
+ scalar dEff = p.d()*cbrt(p.nParticle()*volumeFactor_);
+
+ RMin = min(dEff, RMin);
rhoMax = max(p.rho(), rhoMax);
UMagMax = max
(
- mag(p.U()) + mag(p.omega())*p.d()/2,
+ mag(p.U()) + mag(p.omega())*dEff/2,
UMagMax
);
}
@@ -91,7 +93,8 @@ Foam::PairSpringSliderDashpot<CloudType>::PairSpringSliderDashpot
(
this->coeffDict().lookup("collisionResolutionSteps")
)
- )
+ ),
+ volumeFactor_(this->dict().lookupOrDefault("volumeFactor", 1.0))
{
scalar nu = this->owner().constProps().poissonsRatio();
@@ -155,7 +158,11 @@ void Foam::PairSpringSliderDashpot<CloudType>::evaluatePair
{
vector r_AB = (pA.position() - pB.position());
- scalar normalOverlapMag = 0.5*(pA.d() + pB.d()) - mag(r_AB);
+ scalar dAEff = pA.d()*cbrt(pA.nParticle()*volumeFactor_);
+
+ scalar dBEff = pB.d()*cbrt(pB.nParticle()*volumeFactor_);
+
+ scalar normalOverlapMag = 0.5*(dAEff + dBEff) - mag(r_AB);
if (normalOverlapMag > 0)
{
@@ -166,7 +173,7 @@ void Foam::PairSpringSliderDashpot<CloudType>::evaluatePair
vector U_AB = pA.U() - pB.U();
// Effective radius
- scalar R = 0.5*pA.d()*pB.d()/(pA.d() + pB.d());
+ scalar R = 0.5*dAEff*dBEff/(dAEff + dBEff);
// Effective mass
scalar M = pA.mass()*pB.mass()/(pA.mass() + pB.mass());
@@ -185,8 +192,8 @@ void Foam::PairSpringSliderDashpot<CloudType>::evaluatePair
vector USlip_AB =
U_AB - (U_AB & rHat_AB)*rHat_AB
- + (pA.omega() ^ (pA.d()/2*-rHat_AB))
- - (pB.omega() ^ (pB.d()/2*rHat_AB));
+ + (pA.omega() ^ (dAEff/2*-rHat_AB))
+ - (pB.omega() ^ (dBEff/2*rHat_AB));
scalar deltaT = this->owner().mesh().time().deltaTValue();
@@ -241,8 +248,8 @@ void Foam::PairSpringSliderDashpot<CloudType>::evaluatePair
pA.f() += fT_AB;
pB.f() += -fT_AB;
- pA.torque() += (pA.d()/2*-rHat_AB) ^ fT_AB;
- pB.torque() += (pB.d()/2*rHat_AB) ^ -fT_AB;
+ pA.torque() += (dAEff/2*-rHat_AB) ^ fT_AB;
+ pB.torque() += (dBEff/2*rHat_AB) ^ -fT_AB;
}
}
}
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.H b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.H
index 819e9a835bf..18b30753373 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairModel/PairSpringSliderDashpot/PairSpringSliderDashpot.H
@@ -74,6 +74,24 @@ class PairSpringSliderDashpot
// harmonic approximation of the collision period
scalar collisionResolutionSteps_;
+ //- Volume factor for determining the equivalent size of a
+ // parcel where nParticles is not 1. The equivalent size of
+ // the parcel is
+ // parcelEquivVolume = volumeFactor*nParticles*p.volume()
+ // so
+ // parcelEquivD = cbrt(volumeFactor*nParticles)*p.d()
+ // + When volumeFactor = 1, the particles are compressed
+ // together so that the equivalent volume of the parcel is
+ // the sum of the constituent particles
+ // + When volumeFactor = 3*sqrt(2)/pi, the particles are
+ // close packed, but uncompressed.
+ // + When volumeFactor > 3*sqrt(2)/pi, the particles loosely
+ // grouped.
+ // 3*sqrt(2)/pi = 1.350474 is the volume factor for close
+ // packing, i.e pi/(3*sqrt(2)) is the maximum close packing
+ // factor
+ scalar volumeFactor_;
+
// Private Member Functions
@@ -104,6 +122,12 @@ public:
// Member Functions
+ //- Return the volumeFactor
+ inline scalar volumeFactor() const
+ {
+ return volumeFactor_;
+ }
+
//- Whether the PairModel has a timestep limit that will
// require subCycling
virtual bool controlsTimestep() const;
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallModel/WallModel.H b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallModel/WallModel.H
index 1c4e29a0598..31fde4e2991 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallModel/WallModel.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallModel/WallModel.H
@@ -54,7 +54,7 @@ class WallModel
{
// Private data
- //- The cloud dictionary
+ //- The CollisionModel dictionary
const dictionary& dict_;
//- Reference to the owner cloud class
@@ -120,6 +120,9 @@ public:
// Member Functions
+ //- Return the effective radius for a particle for the model
+ virtual scalar pREff(const typename CloudType::parcelType& p) const = 0;
+
//- Whether the WallModel has a timestep limit that will
// require subCycling
virtual bool controlsTimestep() const = 0;
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.C b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.C
index 3b425d5e129..60c4218a750 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.C
@@ -44,13 +44,16 @@ void Foam::WallSpringSliderDashpot<CloudType>::findMinMaxProperties
const typename CloudType::parcelType& p = iter();
// Finding minimum diameter to avoid excessive arithmetic
- rMin = min(p.d(), rMin);
+
+ scalar dEff = p.d()*cbrt(p.nParticle()*volumeFactor_);
+
+ rMin = min(dEff, rMin);
rhoMax = max(p.rho(), rhoMax);
UMagMax = max
(
- mag(p.U()) + mag(p.omega())*p.d()/2,
+ mag(p.U()) + mag(p.omega())*dEff/2,
UMagMax
);
}
@@ -69,18 +72,17 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
const WallSiteData<vector>& data,
scalar pNu,
scalar pE,
+ scalar pREff,
scalar Estar,
scalar kN,
scalar Gstar
) const
{
- scalar pR = p.d()/2;
-
vector r_PW = p.position() - site;
vector U_PW = p.U() - data.wallData();
- scalar normalOverlapMag = pR - mag(r_PW);
+ scalar normalOverlapMag = pREff - mag(r_PW);
vector rHat_PW = r_PW/(mag(r_PW) + VSMALL);
@@ -94,7 +96,7 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
vector USlip_PW =
U_PW - (U_PW & rHat_PW)*rHat_PW
- + (p.omega() ^ (pR*-rHat_PW));
+ + (p.omega() ^ (pREff*-rHat_PW));
scalar deltaT = this->owner().mesh().time().deltaTValue();
@@ -108,7 +110,7 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
if (tangentialOverlapMag > VSMALL)
{
- scalar kT = 8.0*sqrt(pR*normalOverlapMag)*Gstar;
+ scalar kT = 8.0*sqrt(pREff*normalOverlapMag)*Gstar;
scalar etaT = etaN;
@@ -134,7 +136,7 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
p.f() += fT_PW;
- p.torque() += (pR*-rHat_PW) ^ fT_PW;
+ p.torque() += (pREff*-rHat_PW) ^ fT_PW;
}
}
@@ -160,7 +162,8 @@ Foam::WallSpringSliderDashpot<CloudType>::WallSpringSliderDashpot
(
this->coeffDict().lookup("collisionResolutionSteps")
)
- )
+ ),
+ volumeFactor_(this->dict().lookupOrDefault("volumeFactor", 1.0))
{}
@@ -173,6 +176,15 @@ Foam::WallSpringSliderDashpot<CloudType>::~WallSpringSliderDashpot()
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
+template<class CloudType>
+Foam::scalar Foam::WallSpringSliderDashpot<CloudType>::pREff
+(
+ const typename CloudType::parcelType& p
+) const
+{
+ return p.d()/2*cbrt(p.nParticle()*volumeFactor_);
+}
+
template<class CloudType>
bool Foam::WallSpringSliderDashpot<CloudType>::controlsTimestep() const
{
@@ -225,9 +237,11 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
scalar pE = this->owner().constProps().youngsModulus();
+ scalar pREff = this->pREff(p);
+
scalar Estar = 1/((1 - sqr(pNu))/pE + (1 - sqr(nu_))/E_);
- scalar kN = (4.0/3.0)*sqrt(p.d()/2)*Estar;
+ scalar kN = (4.0/3.0)*sqrt(pREff)*Estar;
scalar GStar = 1/(2*((2 + pNu - sqr(pNu))/pE + (2 + nu_ - sqr(nu_))/E_));
@@ -240,6 +254,7 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
flatSiteData[siteI],
pNu,
pE,
+ pREff,
Estar,
kN,
GStar
@@ -257,6 +272,7 @@ void Foam::WallSpringSliderDashpot<CloudType>::evaluateWall
sharpSiteData[siteI],
pNu,
pE,
+ pREff,
Estar,
kN,
GStar
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.H b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.H
index 452b4ced187..2aefa7d7e7d 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/WallModel/WallSpringSliderDashpot/WallSpringSliderDashpot.H
@@ -69,6 +69,24 @@ class WallSpringSliderDashpot
// harmonic approximation of the collision period
scalar collisionResolutionSteps_;
+ //- Volume factor for determining the equivalent size of a
+ // parcel where nParticles is not 1. The equivalent size of
+ // the parcel is
+ // parcelEquivVolume = volumeFactor*nParticles*p.volume()
+ // so
+ // parcelEquivD = cbrt(volumeFactor*nParticles)*p.d()
+ // + When volumeFactor = 1, the particles are compressed
+ // together so that the equivalent volume of the parcel is
+ // the sum of the constituent particles
+ // + When volumeFactor = 3*sqrt(2)/pi, the particles are
+ // close packed, but uncompressed.
+ // + When volumeFactor > 3*sqrt(2)/pi, the particles loosely
+ // grouped.
+ // 3*sqrt(2)/pi = 1.350474 is the volume factor for close
+ // packing, i.e pi/(3*sqrt(2)) is the maximum close packing
+ // factor
+ scalar volumeFactor_;
+
// Private Member Functions
@@ -89,6 +107,7 @@ class WallSpringSliderDashpot
const WallSiteData<vector>& data,
scalar pNu,
scalar pE,
+ scalar pREff,
scalar Estar,
scalar kN,
scalar Gstar
@@ -113,6 +132,15 @@ public:
// Member Functions
+ //- Return the volumeFactor
+ inline scalar volumeFactor() const
+ {
+ return volumeFactor_;
+ }
+
+ //- Return the effective radius for a particle for the model
+ virtual scalar pREff(const typename CloudType::parcelType& p) const;
+
//- Whether the WallModel has a timestep limit that will
// require subCycling
virtual bool controlsTimestep() const;
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.C b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.C
index a232a5f0609..243b0ab3716 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.C
@@ -217,7 +217,7 @@ Foam::scalar Foam::InjectionModel<CloudType>::setNumberOfParticles
}
case pbFixed:
{
- nP = nParticlesFixed_;
+ nP = nParticleFixed_;
break;
}
default:
@@ -290,7 +290,7 @@ Foam::InjectionModel<CloudType>::InjectionModel(CloudType& owner)
nInjections_(0),
parcelsAddedTotal_(0),
parcelBasis_(pbNumber),
- nParticlesFixed_(0.0),
+ nParticleFixed_(0.0),
time0_(0.0),
timeStep0_(0.0)
{
@@ -316,7 +316,7 @@ Foam::InjectionModel<CloudType>::InjectionModel
nInjections_(0),
parcelsAddedTotal_(0),
parcelBasis_(pbNumber),
- nParticlesFixed_(0.0),
+ nParticleFixed_(0.0),
time0_(owner.db().time().value()),
timeStep0_(0.0)
{
@@ -340,11 +340,11 @@ Foam::InjectionModel<CloudType>::InjectionModel
{
parcelBasis_ = pbFixed;
- Info<< " Choosing nParticles to be a fixed value, massTotal "
+ Info<< " Choosing nParticle to be a fixed value, massTotal "
<< "variable now does not determine anything."
<< endl;
- nParticlesFixed_ = readScalar(coeffDict_.lookup("nParticles"));
+ nParticleFixed_ = readScalar(coeffDict_.lookup("nParticle"));
}
else
{
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.H b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.H
index c6fb6e424bc..4c5d9680488 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModel.H
@@ -138,9 +138,9 @@ protected:
//- Parcel basis enumeration
parcelBasis parcelBasis_;
- //- nParticles to assign to parcels when the 'fixed' basis
+ //- nParticle to assign to parcels when the 'fixed' basis
// is selected
- scalar nParticlesFixed_;
+ scalar nParticleFixed_;
//- Continuous phase time at start of injection time step [s]
scalar time0_;
--
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