comfort.H

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License
    This file is part of OpenFOAM.
 
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Class
    Foam::functionObjects::comfort
 
Description
    Calculates the thermal comfort quantities predicted mean vote (PMV),
    predicted percentage of dissatisfaction (PPD) and the draught rate (DR)
    based on DIN ISO EN 7730:2005.
 
    The draught rate is defined for velocities between 0 m/s and 0.5 m/s. Values
    larger than 0.5 m/s will be set to 0.5 m/s. Furthermore, the draught rate is
    defined between 20 degC and 26 degC. A temperature limitation is not
    implemented. The draught rate is mainly used for HVAC analysis in rooms.
 
Usage
    \table
        Property      | Description                  | Required  | Default value
        clothing      | The insulation value of the cloth | no   | 0
        metabolicRate | The metabolic rate      | no        | 0.8
        extWork       | The external work        | no        | 0
        Trad          | Radiation temperature | no | 0
        relHumidity   | Relative humidity of the air | no | 0.5
        pSat          | Saturation pressure of water | no | -1
        tolerance     | Residual control for the cloth temperature | no | 1e-4
        maxClothIter  | Maximum number of iterations | no       | 100
        meanVelocity  | Use a constant mean velocity in the whole domain | no |\
        false
    \endtable
 
    \table
        Predicted Mean Vote (PMV)   | evaluation
        + 3                         | hot
        + 2                         | warm
        + 1                         | slightly warm
        + 0                         | neutral
        - 1                         | slightly cool
        - 2                         | cool
        - 3                         | cold
    \endtable
 
    \verbatim
    comfortAnalysis
    {
        type            comfort;
        libs            ("libfieldFunctionObjects.so");
 
        executeControl  writeTime;
        writeControl    writeTime;
    }
    \endverbatim
 
SourceFiles
    comfort.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef comfort_H
#define comfort_H
 
#include "fvMeshFunctionObject.H"
#include "volFields.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                           Class comfort Declaration
\*---------------------------------------------------------------------------*/
 
class comfort
:
    public fvMeshFunctionObject
{
    // Private Data
 
        //- Clothing [-]
        dimensionedScalar clothing_;
 
        //- Metabolic rate [kg/s^3]
        dimensionedScalar metabolicRate_;
 
        //- External work [kg/s^3]
        dimensionedScalar extWork_;
 
        //- Switch set to true if the radiation temperature is provided
        Switch TradSet_;
 
        //- Mean radiation temperature [K]
        dimensionedScalar Trad_;
 
        //- Relative humidity [percentage]
        dimensionedScalar relHumidity_;
 
        //- Saturation pressure of water [Pa]
        dimensionedScalar pSat_;
 
        //- Thermal insulation of clothing [W/m^2/K]
        dimensionedScalar Icl_;
 
        //- Prefactor of cloth area [-]
        dimensionedScalar fcl_;
 
        //- Tolerance criteria for iterative process to find Tcl
        scalar tolerance_;
 
        //- Maximum number of correctors for cloth temperature
        int maxClothIter_;
 
        //- Switch to use volume weighted velocity field for calculation
        Switch meanVelocity_;
 
 
    // Private Member Functions
 
        // Calculate the magnitude of the velocity [m/s]
        tmp<volScalarField> magU() const;
 
        // Calculate the radiation temperature in the domain using a simple
        // approach [K]
        dimensionedScalar Trad() const;
 
        // Calculate the saturation pressure based on 7730:2006
        // Possible options: adding different calculation methods such as
        // the formulation based on Magnus or others [Pa]
        tmp<volScalarField> pSat() const;
 
        // Calculate and return the surface temperature of the cloth [K]
        // and the heat transfer coefficient hc [W/m^2/K]
        tmp<volScalarField> Tcloth
        (
            volScalarField& hc,
            const dimensionedScalar& metabolicRateSI,
            const dimensionedScalar& extWorkSI,
            const volScalarField& TdegC,
            const dimensionedScalar& Trad
        );
 
        // Return true if the cloth temperature iteration has converged
        bool converged(const volScalarField&) const;
 
 
public:
 
    //- Runtime type information
    TypeName("comfort");
 
 
    // Constructors
 
        //- Construct from Time and dictionary
        comfort
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );
 
 
    //- Destructor
    virtual ~comfort();
 
 
    // Member Functions
 
        //- Read the data needed for the comfort calculation
        virtual bool read(const dictionary&);
 
        //- Return the list of fields required
        virtual wordList fields() const;
 
        //- Calculate the predicted mean vote (PMV)
        //  and predicted percentage dissatisfaction (PPD) fields
        virtual bool execute();
 
        //- Write the PPD and PMV fields
        virtual bool write();
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //