zeroGradient.H

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/*---------------------------------------------------------------------------*\
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    Copyright (C) 2016-2020 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::functionObjects::zeroGradient
 
Group
    grpFieldFunctionObjects
 
Description
    Creates a volume field with zero-gradient
    boundary conditions from another volume field.
 
    The result can be used, for example, to post-process near-wall
    field values.
 
    Operands:
    \table
      Operand        | Type                | Location
      input          | vol<Type>Field    | $FOAM_CASE/<time>/<inpField>
      output file    | -                   | -
      output field   | vol<Type>Field    | $FOAM_CASE/<time>/<outField>
    \endtable
 
    where \c <Type>=Scalar/Vector/SphericalTensor/SymmTensor/Tensor.
 
Usage
    Minimal example by using \c system/controlDict.functions:
    \verbatim
    zeroGradient1
    {
        // Mandatory entries (unmodifiable)
        type        zeroGradient;
        libs        (fieldFunctionObjects);
 
        // Mandatory entries (runtime modifiable)
        fields      (<field1> ... <fieldN>); \\‍(U "(T|k|epsilon|omega)");
 
        // Optional entries (runtime modifiable)
        result      @@<name>;
 
        // Optional (inherited) entries
        ...
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property     | Description                           | Type | Req'd | Dflt
      type         | Type name: zeroGradient               | word |  yes  | -
      libs         | Library name: fieldFunctionObjects    | word |  yes  | -
      fields       | Name of the operand fields            | wordList | yes | -
      result       | Name of the output field    | word | no | zeroGradient(@@)
    \endtable
 
    The inherited entries are elaborated in:
     - \link functionObject.H \endlink
 
    Usage by the \c postProcess utility is not available.
 
Note
    - A list of fields can contain exact names or regular expressions.
    The token '\@\@' in the result name is replaced by the name of the source
    field. In the special case of a single source field (specified as
    a non-regex), the '\@\@' token checking is suppressed.
    - The function object will skip over fields that would not benefit
    i.e., only processor, empty, zeroGradient, symmetry patches.
    This check should also prevent processing fields multiple times.
 
See also
    - Foam::functionObject
    - Foam::functionObjects::fvMeshFunctionObject
    - ExtendedCodeGuide::functionObjects::field::zeroGradient
 
SourceFiles
    zeroGradient.C
    zeroGradientTemplates.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef functionObjects_zeroGradient_H
#define functionObjects_zeroGradient_H
 
#include "fvMeshFunctionObject.H"
#include "volFieldsFwd.H"
#include "OFstream.H"
#include "wordRes.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                        Class zeroGradient Declaration
\*---------------------------------------------------------------------------*/
 
class zeroGradient
:
    public fvMeshFunctionObject
{
    // Private Data
 
        //- Name of fields to process
        wordRes selectFields_;
 
        //- Formatting for the result fields
        word resultName_;
 
        //- Hashed names of result fields, and their type
        HashTable<word> results_;
 
 
    // Private Member Functions
 
        //- Check that string contains the appropriate substitution token(s)
        static bool checkFormatName(const std::string& str);
 
 
        //- Accept unless field only has constraint patches
        //  (ie, empty/zero-gradient/processor)
        //  This should also avoid fields that were already processed by
        //  zeroGradient.
        template<class Type>
        static bool accept(const GeometricField<Type, fvPatchField, volMesh>&);
 
        //- Apply for the volume field type
        template<class Type>
        int apply(const word& inputName, int& state);
 
        //- Process by trying to apply for various volume field types
        int process(const word& inputName);
 
 
public:
 
    //- Runtime type information
    TypeName("zeroGradient");
 
 
    // Constructors
 
        //- Construct from Time and dictionary
        zeroGradient
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );
 
        //- No copy construct
        zeroGradient(const zeroGradient&) = delete;
 
        //- No copy assignment
        void operator=(const zeroGradient&) = delete;
 
 
    //- Destructor
    virtual ~zeroGradient() = default;
 
 
    // Member Functions
 
        //- Read the zeroGradient specification
        virtual bool read(const dictionary& dict);
 
        //- Calculate the zeroGradient fields
        virtual bool execute();
 
        //- Write the zeroGradient fields
        virtual bool write();
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#ifdef NoRepository
    #include "zeroGradientTemplates.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //