Boundary conditions¶

Contents:

Boundary conditions

Robin boundary conditions apply a heat flux condition to temperature on an external wall.

Two boundary conditions are available in this library: the mould HTC and the water film HTC.

Installation¶

Pre-requisites:

A working installation of OpenFOAM 9.

In the directChillFoam/src/ThermophysicalTransportModels directory, run:

$ wmake libso

Mould heat transfer coefficient¶

class mouldHTCFvPatchScalarField : public mixedFvPatchScalarField, public temperatureCoupledBase¶

This boundary condition applies a heat flux condition to temperature on an external wall in one of three modes:

fixed power: supply \( Q \)
fixed heat flux: supply \( q \)
fixed heat transfer coefficient: supply \( h \) and \( Ta \)

where:

\( Q \)	=	Power [W]
\( q \)	=	Heat flux [W/m^2]
\( h \)	=	Heat transfer coefficient [W/m^2/K]
\( Ta \)	=	Ambient temperature [K]

For heat transfer coefficient mode, optional thin thermal layer resistances can be specified through thicknessLayers and kappaLayers entries.

The thermal conductivity kappa can either be retrieved from various possible sources, as detailed in the class temperatureCoupledBase.

The ambient temperature \( Ta \) is specified as a Foam::Function1 of time but uniform in space.

See also

Foam::temperatureCoupledBase Foam::mixedFvPatchScalarField Foam::waterFilmHTCFvPatchScalarField

Usage

Property	Description	Required	Default value
`mode`	’power’, ‘flux’ or ‘coefficient’	yes
`Q`	Power [W]	for mode ‘power’
`q`	Heat flux [W/m^2]	for mode ‘flux’
`h1`	mould heat transfer coefficient [W/m^2/K]	yes*
`h2`	air gap heat transfer coefficient [W/m^2/K]	yes*
`Ta`	Ambient temperature [K]	for mode ‘coefficient’
`thicknessLayers`	Layer thicknesses [m]	no
`kappaLayers`	Layer thermal conductivities [W/m/K]	no
`relaxation`	Relaxation for the wall temperature	no	1
`emissivity`	Surface emissivity for radiative flux to ambient	no	0
`qr`	Name of the radiative field	no	none
`qrRelaxation`	Relaxation factor for radiative field	no	1

Example of the boundary condition specification:

<patchName>
{
    type            mouldHTC;

    mode            coefficient;

    Ta              constant 300.0;
    h1              uniform 100.0;
    h2              uniform 10.0;
    thicknessLayers (0.1 0.2 0.3 0.4);
    kappaLayers     (1 2 3 4);

    value           $internalField;
}

Source files

Public Types

enum operationMode¶

Operation mode enumeration.

Values:

enumerator fixedPower¶

enumerator fixedHeatFlux¶

enumerator variableHeatTransferCoeff¶

Public Functions

TypeName ("mouldHTC"): Runtime type information.

mouldHTCFvPatchScalarField(const fvPatch&, const DimensionedField<scalar, volMesh>&)¶: Construct from patch and internal field.

mouldHTCFvPatchScalarField(const fvPatch&, const DimensionedField<scalar, volMesh>&, const dictionary&)¶: Construct from patch, internal field and dictionary.

mouldHTCFvPatchScalarField(const mouldHTCFvPatchScalarField&, const fvPatch&, const DimensionedField<scalar, volMesh>&, const fvPatchFieldMapper&)¶

Construct by mapping given.

mouldHTCFvPatchScalarField onto a new patch

mouldHTCFvPatchScalarField(const mouldHTCFvPatchScalarField&) = delete¶: Disallow copy without setting internal field reference.

mouldHTCFvPatchScalarField(const mouldHTCFvPatchScalarField&, const DimensionedField<scalar, volMesh>&)¶: Copy constructor setting internal field reference.

inline virtual tmp<fvPatchScalarField> clone(const DimensionedField<scalar, volMesh> &iF) const¶: Construct and return a clone setting internal field reference.

inline virtual bool fixesValue() const¶: Allow manipulation of the boundary values.

virtual void autoMap(const fvPatchFieldMapper&)¶

Map (and resize as needed) from self given a mapping object.

Used to update fields following mesh topology change

virtual void rmap(const fvPatchScalarField&, const labelList&)¶

Reverse map the given fvPatchField onto this fvPatchField.

Used to reconstruct fields

virtual void updateCoeffs()¶: Update the coefficients associated with the patch field.

void write(Ostream&) const¶: Write.

Water film heat transfer coefficient¶

class waterFilmHTCFvPatchScalarField : public mixedFvPatchScalarField, public temperatureCoupledBase¶