fc6b44ee3c
This formulation provides C-grid like pressure-flux staggering on an
unstructured mesh which is hugely beneficial for Euler-Euler multiphase
equations as it allows for all forces to be treated in a consistent
manner on the cell-faces which provides better balance, stability and
accuracy. However, to achieve face-force consistency the momentum
transport terms must be interpolated to the faces reducing accuracy of
this part of the system but this is offset by the increase in accuracy
of the force-balance.
Currently it is not clear if this face-based momentum equation
formulation is preferable for all Euler-Euler simulations so I have
included it on a switch to allow evaluation and comparison with the
previous cell-based formulation. To try the new algorithm simply switch
it on, e.g.:
PIMPLE
{
nOuterCorrectors 3;
nCorrectors 1;
nNonOrthogonalCorrectors 0;
faceMomentum yes;
}
It is proving particularly good for bubbly flows, eliminating the
staggering patterns often seen in the air velocity field with the
previous algorithm, removing other spurious numerical artifacts in the
velocity fields and improving stability and allowing larger time-steps
For particle-gas flows the advantage is noticeable but not nearly as
pronounced as in the bubbly flow cases.
Please test the new algorithm on your cases and provide feedback.
Henry G. Weller
CFD Direct
156 lines
4.6 KiB
C++
156 lines
4.6 KiB
C++
/*---------------------------------------------------------------------------*\
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========= |
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\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
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\\ / O peration |
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\\ / A nd | Copyright (C) 2014-2015 OpenFOAM Foundation
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\\/ M anipulation |
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-------------------------------------------------------------------------------
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License
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This file is part of OpenFOAM.
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OpenFOAM is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
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Class
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Foam::BlendedInterfacialModel
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Description
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SourceFiles
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BlendedInterfacialModel.C
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\*---------------------------------------------------------------------------*/
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#ifndef BlendedInterfacialModel_H
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#define BlendedInterfacialModel_H
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#include "blendingMethod.H"
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#include "phasePair.H"
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#include "orderedPhasePair.H"
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#include "geometricZeroField.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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namespace Foam
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{
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/*---------------------------------------------------------------------------*\
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Class BlendedInterfacialModel Declaration
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\*---------------------------------------------------------------------------*/
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template<class modelType>
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class BlendedInterfacialModel
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{
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// Private data
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//- Unordered phase pair
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const phasePair& pair_;
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//- Ordered phase pair for dispersed phase 1 in continuous phase 2
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const orderedPhasePair& pair1In2_;
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//- Ordered phase pair for dispersed phase 2 in continuous phase 1
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const orderedPhasePair& pair2In1_;
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//- Model for region with no obvious dispersed phase
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autoPtr<modelType> model_;
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//- Model for dispersed phase 1 in continuous phase 2
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autoPtr<modelType> model1In2_;
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//- Model for dispersed phase 2 in continuous phase 1
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autoPtr<modelType> model2In1_;
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//- Blending model
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const blendingMethod& blending_;
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//- If true set coefficients and forces to 0 at fixed-flux BCs
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bool correctFixedFluxBCs_;
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// Private Member Functions
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//- Disallow default bitwise copy construct
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BlendedInterfacialModel(const BlendedInterfacialModel<modelType>&);
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//- Disallow default bitwise assignment
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void operator=(const BlendedInterfacialModel<modelType>&);
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//- Correct coeff/value on fixed flux boundary conditions
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template<class GeometricField>
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void correctFixedFluxBCs(GeometricField& field) const;
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public:
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// Constructors
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//- Construct from the model table, dictionary and pairs
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BlendedInterfacialModel
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(
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const phasePair::dictTable& modelTable,
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const blendingMethod& blending,
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const phasePair& pair,
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const orderedPhasePair& pair1In2,
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const orderedPhasePair& pair2In1,
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const bool correctFixedFluxBCs = true
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);
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//- Destructor
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~BlendedInterfacialModel();
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// Member Functions
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//- Return true if a model is specified for the supplied phase
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bool hasModel(const phaseModel& phase) const;
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//- Return the model for the supplied phase
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const modelType& phaseModel(const phaseModel& phase) const;
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//- Return the blended force coefficient
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tmp<volScalarField> K() const;
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//- Return the face blended force coefficient
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tmp<surfaceScalarField> Kf() const;
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//- Return the blended force
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template<class Type>
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tmp<GeometricField<Type, fvPatchField, volMesh> > F() const;
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//- Return the face blended force
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tmp<surfaceScalarField> Ff() const;
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//- Return the blended diffusivity
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tmp<volScalarField> D() const;
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};
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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} // End namespace Foam
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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#ifdef NoRepository
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#include "BlendedInterfacialModel.C"
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#endif
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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#endif
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// ************************************************************************* //
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