dalpeMassonCanopySource.H

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/*---------------------------------------------------------------------------*\
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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/>.
 
    Copyright is held by the author.
 
Class
    Foam::fv::dalpeMassonCanopySource
 
Group
    grpFvOptionsSources
 
Author
    David Segersson, Swedish Meteorological and Hydrological Institute, david.segersson@smhi.se
 
Description
    
    Momentum source term is expressed as:
        \f[
            S_u = -\rho C_d \alpha u^2
        \f]
 
    Source term for k is expressed as:
 
        \f[
            S_k = \rho C_d \alpha \left(\beta_p u^3 - \beta_d k u \right)
        \f]
 
    Source term for epsilon is expressed as:
 
        \f[
            S_{\epsilon}=\rho C_d \alpha \frac{\epsilon}{k} \left(C_{\epsilon 4} \beta_p u^3 - C_{\epsilon 5} \beta_d k u \right)
        \f]
 
    where
    \beta_p (1.0), \betad_d (5.03), C_{\epsilon 4} (0.78) and C_{epsilon 5} (0.78) are dimensionless coefficients
    \vartable
        \rho           | density
        u              | magnitude of velocity
        k              | turbulent kinetic energy
        \alpha         | leaf area density [m]
        C_d            | tree canopy drag coefficient
    \endvartable
 
    Use with any variant of the k-\epsilon turbulence model.
 
    Reference:
       Momentum and turbulence source/sink-terms for tree canopy according to
       B. Dalpé and C. Masson. Numerical simulation of wind flow near a forest
       edge. J. of Wind Eng. and Ind. Aerodyn, 2006
 
    
Usage
    Example usage:
    \verbatim
    canopy
    {
        type                       dalpeMassonCanopySource;
        active                     on;              // toggle the option
        writeFields                on;              // write to disk
        readLanduseFromRaster      on;              // read landuse from raster
        readCanopyHeightFromRaster on;              // read canopy height from raster
        sourcePatches              (ground forest); // for which patches to set landuse
        patchLanduse               (0 1);           // landuse code per patch (if not read from raster)
 
        landuse
        {
 
            low_birch                               // name of landuse class
            {
                code 1;                             // code of landuse class
                Cd 0.2;                             // drag coefficient of trees
                LAI 2.15;                           // Leaf Area Index (used if LADmax is not specified)
                LADmax 1.2;                         // Maximum Leaf Area Density [m ^-1]
                z0 0.06;                            // roughness length [m]
                height 7.5;                         // tree canopy height (if not read from raster)
                
                // Vertical profile of Leaf Area Density
                // first value is closest to ground
                // each value represents an equal share of the tree height
                // e.g. for a 4 m tree and 4 values, each value will represent 1 m
                // values are scaled so that the highest will correspond to LADMax                
 
                LADProfile ( 0.05 0.1 0.15 0.35 1.1 0.9 0.5 0.2 0.15 0.05 0.01 );
            };
 
            grass
            {
                code 0;
                Cd 0.2;
                LAI 0;
                z0 0.06;
                height 0;
                LADProfile ( 0.05 0.1 0.15 0.35 1.1 0.9 0.5 0.2 0.15 0.05 0.01 );
            };
 
        };
    }
    \endverbatim
 
SourceFiles
    dalpeMassonCanopySource.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef dalpeMassonCanopySource_H
#define dalpeMassonCanopySource_H
 
#include "fvOption.H"
#include "dimensionedTypes.H"
#include "wallFvPatch.H"
#include "canopySource.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace fv
{
 
/*---------------------------------------------------------------------------*\
                 Class dalpeMassonCanopySource Declaration
\*---------------------------------------------------------------------------*/
 
class dalpeMassonCanopySource
:
    public canopySource
{
private:
 
        // Canopy coefficients
        dimensionedScalar betaP_;
        dimensionedScalar betaD_;
        dimensionedScalar C4_;
        dimensionedScalar C5_;
  
        //- Disallow default bitwise copy construct
        dalpeMassonCanopySource(const dalpeMassonCanopySource&);
 
        //- Disallow default bitwise assignment
        void operator=(const dalpeMassonCanopySource&);
 
 
        //- Source term to momentum equation
        template<class RhoFieldType>
        void addSup
        (
            const RhoFieldType& rho,
            fvMatrix<vector>& eqn,
            const label fieldi
        );
 
        template<class RhoFieldType>
        void addSup
        (
            const RhoFieldType& rho,
            fvMatrix<scalar>& eqn,
            const label fieldi
        );
 
 
        // Private Member Functions
 
  
public:
 
 
    //- Runtime type information
    TypeName("dalpeMassonCanopySource");
 
 
    // Constructors
 
        //- Construct from components
        dalpeMassonCanopySource
        (
            const word& name,
            const word& modelType,
            const dictionary& dict,
            const fvMesh& mesh
        );
 
 
    //- Destructor
    virtual ~dalpeMassonCanopySource()
    {}
 
 
    // Member Functions
        // access
 
       dimensionedScalar betaP() const
        {
            return betaP_;
        }
 
       dimensionedScalar betaD() const
        {
            return betaD_;
        }
 
       dimensionedScalar C4() const
        {
            return C4_;
        }
 
       dimensionedScalar C5() const
        {
            return C5_;
        }
 
        // add source terms to momentum equations
        void addSup
        (
            const volScalarField& rho,
            fvMatrix<vector>& eqn,
            const label fieldi
        );
 
        void addSup
        (
            fvMatrix<vector>& eqn,
            const label fieldi
        );
 
 
        //- Source term to scalar equations (k & epsilon)
        void addSup
        (
            fvMatrix<scalar>& eqn,
            const label fieldi
        );
 
        //- Source term to compressible scalar equation (k & epsilon)
        void addSup
        (
            const volScalarField& rho,
            fvMatrix<scalar>& eqn,
            const label fieldi
        );
 
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace fv
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //