momentum.H

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    Copyright (C) 2018-2021 OpenCFD Ltd.
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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::momentum
 
Group
    grpFieldFunctionObjects
 
Description
    Computes linear/angular momentum, reporting integral values and optionally
    writing the fields.
 
    Operands:
    \table
      Operand       | Type | Location
      input         | -    | -
      output file   | dat  | postProcessing/<FO>/<time>/file
      output field  | -    | -
    \endtable
 
Usage
    Minimal example by using \c system/controlDict.functions:
    \verbatim
    momentumFO
    {
        // Mandatory entries
        type            momentum;
        libs            (fieldFunctionObjects);
 
        // Optional entries
        regionType      <word>;;
        writeMomentum   <bool>;
        writePosition   <bool>;
        writeVelocity   <bool>;
        p               <word>;
        U               <word>;
        rho             <word>;
        rhoRef          <scalar>;
        cylindrical     <bool>;
 
        // Conditional entries
 
            // when 'cylindrical' is 'true'
            origin          (0 0 0);
            e1              (1 0 0);
            e3              (0 0 1);
 
        // Inherited entries
        ...
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property     | Description                        | Type | Reqd  | Deflt
      type         | Type name: momentum                | word |  yes  | -
      libs         | Library name: fieldFunctionObjects | word |  yes  | -
      regionType   | Selection type: all/cellSet/cellZone | word   | no  | all
      writeMomentum | Write (linear, angular) momentum  fields | bool | no | no
      writePosition | Write angular position component fields | bool | no  | no
      writeVelocity | Write angular velocity fields           | bool | no  | no
      p            | Pressure field name                | word | no  | p
      U            | Velocity field name                | word | no  | U
      rho          | Density field name                 | word | no  | rho
      rhoRef       | Reference density (incompressible) | scalar | no  | 1.0
      cylindrical  | Use cylindrical coordinates        | bool | no  | no
      origin  | Origin for cylindrical coordinates   | vector | conditional  | -
      name    | Name of cellSet/cellZone if required | word   | conditional  | -
    \endtable
 
    The inherited entries are elaborated in:
      - \link functionObject.H \endlink
      - \link writeFile.H \endlink
 
Note
  - For incompressible cases, the value of \c rhoRef is used.
  - When specifying the cylindrical coordinate system, the rotation
    can be specified directly with e1/e2/e3 axes, or via a \c rotation
    sub-dictionary
    For example,
    \verbatim
        origin      (0 0 0);
        rotation
        {
            type    cylindrical;
            axis    (0 0 1);
        }
    \endverbatim
 
SourceFiles
    momentum.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef Foam_functionObjects_momentum_H
#define Foam_functionObjects_momentum_H
 
#include "fvMeshFunctionObject.H"
#include "writeFile.H"
#include "cylindricalCS.H"
#include "volFieldsFwd.H"
#include "volRegion.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
// Forward Declarations
class dimensionSet;
 
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                           Class momentum Declaration
\*---------------------------------------------------------------------------*/
 
class momentum
:
    public fvMeshFunctionObject,
    public volRegion,
    public writeFile
{
    // Private Member Functions
 
        //- Remove calculated fields from the registry
        void purgeFields();
 
        //- Calculate the fields and integral values
        void calc();
 
        //- Allocate a new zero geometric field
        template<class GeoField>
        autoPtr<GeoField> newField
        (
            const word& baseName,
            const dimensionSet& dims,
            bool registerObject=true
        ) const;
 
 
protected:
 
    // Protected Data
 
        //- Integral (linear) momentum
        vector sumMomentum_;
 
        //- Integral angular momentum
        vector sumAngularMom_;
 
 
    // Read from dictionary
 
        //- The velocity field name (optional)
        word UName_;
 
        //- The pressure field name (optional)
        //  Only used to determine incompressible/compressible
        word pName_;
 
        //- The density field name (optional)
        word rhoName_;
 
        //- Reference density (for incompressible)
        scalar rhoRef_;
 
        //- Coordinate system for evaluating angular momentum
        coordSystem::cylindrical csys_;
 
        //- Are we using the cylindrical coordinate system?
        bool hasCsys_;
 
        //- Write fields flag
        bool writeMomentum_;
 
        //- Write fields flag
        bool writeVelocity_;
 
        //- Write fields flag
        bool writePosition_;
 
        //- Initialised flag
        bool initialised_;
 
 
    // Protected Member Functions
 
        //- Initialise the fields
        void initialise();
 
        //- Output file header information
        virtual void writeFileHeader(Ostream& os);
 
        //- Write momentum data
        void writeValues(Ostream& os);
 
 
public:
 
    //- Runtime type information
    TypeName("momentum");
 
 
    // Constructors
 
        //- Construct from name, Time and dictionary
        momentum
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict,
            const bool readFields = true
        );
 
        //- Construct from objectRegistry and dictionary
        momentum
        (
            const word& name,
            const objectRegistry& obr,
            const dictionary& dict,
            const bool readFields = true
        );
 
        //- No copy construct
        momentum(const momentum&) = delete;
 
        //- No copy assignment
        void operator=(const momentum&) = delete;
 
 
    //- Destructor
    virtual ~momentum() = default;
 
 
    // Member Functions
 
        //- Read the function-object dictionary
        virtual bool read(const dictionary& dict);
 
        //- Execute the function-object operations
        virtual bool execute();
 
        //- Write the function-object results
        virtual bool write();
 
        //- Update for changes of mesh
        virtual void updateMesh(const mapPolyMesh&);
 
        //- Update for mesh point-motion
        virtual void movePoints(const polyMesh&);
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //