The old separate incompressible and compressible libraries have been removed. Most of the commonly used RANS and LES models have been upgraded to the new framework but there are a few missing which will be added over the next few days, in particular the realizable k-epsilon model. Some of the less common incompressible RANS models have been introduced into the new library instantiated for incompressible flow only. If they prove to be generally useful they can be templated for compressible and multiphase application. The Spalart-Allmaras DDES and IDDES models have been thoroughly debugged, removing serious errors concerning the use of S rather than Omega. The compressible instances of the models have been augmented by a simple backward-compatible eddyDiffusivity model for thermal transport based on alphat and alphaEff. This will be replaced with a separate run-time selectable thermal transport model framework in a few weeks. For simplicity and ease of maintenance and further development the turbulent transport and wall modeling is based on nut/nuEff rather than mut/muEff for compressible models so that all forms of turbulence models can use the same wall-functions and other BCs. All turbulence model selection made in the constant/turbulenceProperties dictionary with RAS and LES as sub-dictionaries rather than in separate files which added huge complexity for multiphase. All tutorials have been updated so study the changes and update your own cases by comparison with similar cases provided. Sorry for the inconvenience in the break in backward-compatibility but this update to the turbulence modeling is an essential step in the future of OpenFOAM to allow more models to be added and maintained for a wider range of cases and physics. Over the next weeks and months more turbulence models will be added of single and multiphase flow, more additional sub-models and further development and testing of existing models. I hope this brings benefits to all OpenFOAM users. Henry G. Weller
256 lines
7.0 KiB
C++
256 lines
7.0 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) 2011-2015 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::XiModel
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Description
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Base-class for all Xi models used by the b-Xi combustion model.
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See Technical Report SH/RE/01R for details on the PDR modelling.
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Xi is given through an algebraic expression (\link algebraic.H \endlink),
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by solving a transport equation (\link transport.H \endlink) or a
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fixed value (\link fixed.H \endlink).
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See report TR/HGW/10 for details on the Weller two equations model.
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In the algebraic and transport methods \f$\Xi_{eq}\f$ is calculated in
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similar way. In the algebraic approach, \f$\Xi_{eq}\f$ is the value used in
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the \f$ b \f$ transport equation.
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\f$\Xi_{eq}\f$ is calculated as follows:
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\f$\Xi_{eq} = 1 + (1 + 2\Xi_{coeff}(0.5 - \dwea{b}))(\Xi^* - 1)\f$
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where:
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\f$ \dwea{b} \f$ is the regress variable.
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\f$ \Xi_{coeff} \f$ is a model constant.
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\f$ \Xi^* \f$ is the total equilibrium wrinkling combining the effects
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of the flame inestability and turbulence interaction and is given by
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\f[
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\Xi^* = \frac {R}{R - G_\eta - G_{in}}
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\f]
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where:
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\f$ G_\eta \f$ is the generation rate of wrinkling due to turbulence
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interaction.
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\f$ G_{in} = \kappa \rho_{u}/\rho_{b} \f$ is the generation
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rate due to the flame inestability.
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By adding the removal rates of the two effects:
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\f[
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R = G_\eta \frac{\Xi_{\eta_{eq}}}{\Xi_{\eta_{eq}} - 1}
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+ G_{in} \frac{\Xi_{{in}_{eq}}}{\Xi_{{in}_{eq}} - 1}
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\f]
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where:
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\f$ R \f$ is the total removal.
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\f$ G_\eta \f$ is a model constant.
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\f$ \Xi_{\eta_{eq}} \f$ is the flame wrinkling due to turbulence.
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\f$ \Xi_{{in}_{eq}} \f$ is the equilibrium level of the flame wrinkling
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generated by inestability. It is a constant (default 2.5).
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SourceFiles
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XiModel.C
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\*---------------------------------------------------------------------------*/
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#ifndef XiModel_H
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#define XiModel_H
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#include "IOdictionary.H"
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#include "psiuReactionThermo.H"
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#include "turbulentFluidThermoModel.H"
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#include "multivariateSurfaceInterpolationScheme.H"
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#include "fvcDiv.H"
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#include "runTimeSelectionTables.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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namespace Foam
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{
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/*---------------------------------------------------------------------------*\
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Class XiModel Declaration
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\*---------------------------------------------------------------------------*/
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class XiModel
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{
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protected:
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// Protected data
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dictionary XiModelCoeffs_;
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const psiuReactionThermo& thermo_;
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const compressible::RASModel& turbulence_;
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const volScalarField& Su_;
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const volScalarField& rho_;
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const volScalarField& b_;
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const surfaceScalarField& phi_;
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//- Flame wrinking field
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volScalarField Xi_;
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private:
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// Private Member Functions
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//- Disallow copy construct
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XiModel(const XiModel&);
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//- Disallow default bitwise assignment
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void operator=(const XiModel&);
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public:
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//- Runtime type information
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TypeName("XiModel");
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// Declare run-time constructor selection table
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declareRunTimeSelectionTable
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(
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autoPtr,
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XiModel,
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dictionary,
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(
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const dictionary& XiProperties,
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const psiuReactionThermo& thermo,
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const compressible::RASModel& turbulence,
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const volScalarField& Su,
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const volScalarField& rho,
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const volScalarField& b,
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const surfaceScalarField& phi
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),
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(
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XiProperties,
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thermo,
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turbulence,
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Su,
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rho,
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b,
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phi
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)
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);
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// Selectors
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//- Return a reference to the selected Xi model
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static autoPtr<XiModel> New
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(
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const dictionary& XiProperties,
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const psiuReactionThermo& thermo,
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const compressible::RASModel& turbulence,
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const volScalarField& Su,
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const volScalarField& rho,
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const volScalarField& b,
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const surfaceScalarField& phi
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);
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// Constructors
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//- Construct from components
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XiModel
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(
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const dictionary& XiProperties,
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const psiuReactionThermo& thermo,
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const compressible::RASModel& turbulence,
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const volScalarField& Su,
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const volScalarField& rho,
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const volScalarField& b,
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const surfaceScalarField& phi
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);
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//- Destructor
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virtual ~XiModel();
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// Member Functions
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//- Return the flame-wrinking Xi
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virtual const volScalarField& Xi() const
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{
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return Xi_;
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}
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//- Return the flame diffusivity
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virtual tmp<volScalarField> Db() const
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{
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return turbulence_.muEff();
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}
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//- Add Xi to the multivariateSurfaceInterpolationScheme table
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// if required
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virtual void addXi
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(
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multivariateSurfaceInterpolationScheme<scalar>::fieldTable&
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)
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{}
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//- Correct the flame-wrinking Xi
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virtual void correct() = 0;
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//- Correct the flame-wrinking Xi using the given convection scheme
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virtual void correct(const fv::convectionScheme<scalar>&)
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{
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correct();
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}
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//- Update properties from given dictionary
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virtual bool read(const dictionary& XiProperties) = 0;
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//- Write fields related to Xi model
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virtual void writeFields() = 0;
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};
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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} // End namespace Foam
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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#endif
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// ************************************************************************* //
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