Lambda2.H

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    Copyright (C) 2013-2016 OpenFOAM Foundation
    Copyright (C) 2020-2023 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::Lambda2
 
Group
    grpFieldFunctionObjects
 
Description
    Computes the second largest eigenvalue of the sum of the square of
    the symmetrical and anti-symmetrical parts of the velocity gradient tensor.
 
    Operands:
    \table
      Operand          | Type           | Location
      input            | volVectorField | <time>/inputField
      output file      | -              | -
      output field     | volScalarField | <time>/outputField
    \endtable
 
    References:
    \verbatim
        Governing equation (tag:JH):
            Jeong, J., & Hussain, F. (1995).
            On the identification of a vortex.
            Journal of Fluid Mechanics, 285, 69-94.
            DOI:10.1017/S0022112095000462
    \endverbatim
 
Usage
    Minimal example by using \c system/controlDict.functions:
    \verbatim
    Lambda2FO
    {
        // Mandatory entries
        type            Lambda2;
        libs            (fieldFunctionObjects);
 
        // Inherited entries
        ...
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property     | Description                        | Type | Reqd | Deflt
      type         | Type name: Lambda2                 | word | yes  | -
      libs         | Library name: fieldFunctionObjects | word | yes  | -
    \endtable
 
    The inherited entries are elaborated in:
      - \link fieldExpression.H \endlink
 
SourceFiles
    Lambda2.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef Foam_functionObjects_Lambda2_H
#define Foam_functionObjects_Lambda2_H
 
#include "fieldExpression.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                          Class Lambda2 Declaration
\*---------------------------------------------------------------------------*/
 
class Lambda2
:
    public fieldExpression
{
    // Private Member Functions
 
        //- Calculate the Lambda2 field and return true if successful
        virtual bool calc();
 
 
public:
 
    //- Runtime type information
    TypeName("Lambda2");
 
 
    // Constructors
 
        //- Construct from name, Time and dictionary
        Lambda2
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );
 
        //- No copy construct
        Lambda2(const Lambda2&) = delete;
 
        //- No copy assignment
        void operator=(const Lambda2&) = delete;
 
 
    //- Destructor
    virtual ~Lambda2() = default;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //