grad.H

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/*---------------------------------------------------------------------------*\
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-------------------------------------------------------------------------------
    Copyright (C) 2012-2016 OpenFOAM Foundation
    Copyright (C) 2019-2020 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::grad
 
Group
    grpFieldFunctionObjects
 
Description
    Computes the gradient of an input field.
 
    The operation is limited to scalar and vector volume or surface fields, and
    the output is a volume vector or tensor field.
 
    Operands:
    \table
      Operand       | Type                              | Location
      input         | {vol,surface}{Scalar,Vector}Field <!--
                --> | $FOAM_CASE/<time>/<inpField>
      output file   | -                                 | -
      output field  | vol{Vector,Tensor}Field           <!--
                --> | $FOAM_CASE/<time>/<outField>
    \endtable
 
Usage
    Minimal example by using \c system/controlDict.functions:
    \verbatim
    grad1
    {
        // Mandatory entries (unmodifiable)
        type            grad;
        libs            (fieldFunctionObjects);
 
        // Mandatory (inherited) entries (runtime modifiable)
        field           <field>;
 
        // Optional (inherited) entries
        ...
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property     | Description                        | Type | Req'd | Dflt
      type         | Type name: grad                    | word |  yes  | -
      libs         | Library name: fieldFunctionObjects | word |  yes  | -
      field        | Name of the operand field          | word |  yes  | -
    \endtable
 
    The inherited entries are elaborated in:
     - \link functionObject.H \endlink
     - \link fieldExpression.H \endlink
 
    Minimal example by using the \c postProcess utility:
    \verbatim
        postProcess -func "grad(<field>)"
    \endverbatim
 
See also
    - Foam::functionObject
    - Foam::functionObjects::fvMeshFunctionObject
    - Foam::functionObjects::fieldExpression
    - ExtendedCodeGuide::functionObjects::field::grad
 
SourceFiles
    grad.C
    gradTemplates.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef functionObjects_grad_H
#define functionObjects_grad_H
 
#include "fieldExpression.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                         Class grad Declaration
\*---------------------------------------------------------------------------*/
 
class grad
:
    public fieldExpression
{
    // Private Member Functions
 
        //- Calculate the magnitude of the field and register the result
        template<class Type>
        bool calcGrad();
 
        //- Calculate the gradient field and return true if successful
        virtual bool calc();
 
 
public:
 
    //- Runtime type information
    TypeName("grad");
 
 
    // Constructors
 
        //- Construct from Time and dictionary
        grad
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );
 
        //- No copy construct
        grad(const grad&) = delete;
 
        //- No copy assignment
        void operator=(const grad&) = delete;
 
 
    //- Destructor
    virtual ~grad() = default;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#ifdef NoRepository
    #include "gradTemplates.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //