Base-class for all Xi models used by the b-Xi combustion model. See Technical Report SH/RE/01R for details on the PDR modelling. More...

Detailed Description

Base-class for all Xi models used by the b-Xi combustion model. See Technical Report SH/RE/01R for details on the PDR modelling.

Xi is given through an algebraic expression (algebraic.H), by solving a transport equation (transport.H) or a fixed value (fixed.H).

See report TR/HGW/10 for details on the Weller two equations model.

In the algebraic and transport methods $\Xi_{eq}$ is calculated in similar way. In the algebraic approach, $\Xi_{eq}$ is the value used in the $ b $ transport equation.

$\Xi_{eq}$ is calculated as follows:

$\Xi_{eq} = 1 + (1 + 2\Xi_{coeff}(0.5 - \dwea{b}))(\Xi^* - 1)$

where:

$\dwea{b}$ is the regress variable.

$\Xi_{coeff}$ is a model constant.

$\Xi^*$ is the total equilibrium wrinkling combining the effects of the flame inestability and turbulence interaction and is given by

$\Xi^* = \frac {R}{R - G_\eta - G_{in}}$

where:

$G_\eta$ is the generation rate of wrinkling due to turbulence interaction.

$G_{in} = \kappa \rho_{u}/\rho_{b}$ is the generation rate due to the flame inestability.

By adding the removal rates of the two effects:

$R = G_\eta \frac{\Xi_{\eta_{eq}}}{\Xi_{\eta_{eq}} - 1} + G_{in} \frac{\Xi_{{in}_{eq}}}{\Xi_{{in}_{eq}} - 1}$

where:

$ R $ is the total removal.

$G_\eta$ is a model constant.

$\Xi_{\eta_{eq}}$ is the flame wrinkling due to turbulence.

$\Xi_{{in}_{eq}}$ is the equilibrium level of the flame wrinkling generated by inestability. It is a constant (default 2.5).

Source files

Definition at line 108 of file XiModel.H.

Inheritance diagram for XiModel:

Collaboration diagram for XiModel:

List of all members.

Public Member Functions
	TypeName ("XiModel")
	Runtime type information.
	declareRunTimeSelectionTable (autoPtr, XiModel, dictionary,(const dictionary &XiProperties, const hhuCombustionThermo &thermo, const compressible::RASModel &turbulence, const volScalarField &Su, const volScalarField &rho, const volScalarField &b, const surfaceScalarField &phi),(XiProperties, thermo, turbulence, Su, rho, b, phi))
	XiModel (const dictionary &XiProperties, const hhuCombustionThermo &thermo, const compressible::RASModel &turbulence, const volScalarField &Su, const volScalarField &rho, const volScalarField &b, const surfaceScalarField &phi)
	Construct from components.
virtual	~XiModel ()
virtual const volScalarField &	Xi () const
	Return the flame-wrinking Xi.
virtual tmp< volScalarField >	Db () const
	Return the flame diffusivity.
virtual void	addXi (multivariateSurfaceInterpolationScheme< scalar >::fieldTable &)
	Add Xi to the multivariateSurfaceInterpolationScheme table.
virtual void	correct ()=0
	Correct the flame-wrinking Xi.
virtual void	correct (const fv::convectionScheme< scalar > &)
	Correct the flame-wrinking Xi using the given convection scheme.
virtual bool	read (const dictionary &XiProperties)=0
	Update properties from given dictionary.
Static Public Member Functions
static autoPtr< XiModel >	New (const dictionary &XiProperties, const hhuCombustionThermo &thermo, const compressible::RASModel &turbulence, const volScalarField &Su, const volScalarField &rho, const volScalarField &b, const surfaceScalarField &phi)
	Return a reference to the selected Xi model.
Protected Attributes
dictionary	XiModelCoeffs_
const hhuCombustionThermo &	thermo_
const compressible::RASModel &	turbulence_
const volScalarField &	Su_
const volScalarField &	rho_
const volScalarField &	b_
const surfaceScalarField &	phi_
volScalarField	Xi_
	Flame wrinking field.

Constructor & Destructor Documentation

XiModel	(	const dictionary &	XiProperties,
		const hhuCombustionThermo &	thermo,
		const compressible::RASModel &	turbulence,
		const volScalarField &	Su,
		const volScalarField &	rho,
		const volScalarField &	b,
		const surfaceScalarField &	phi
	)

Construct from components.

virtual ~XiModel ( ) [virtual]

Member Function Documentation

TypeName ( "XiModel" )

Runtime type information.

declareRunTimeSelectionTable	(	autoPtr	,
		XiModel	,
		dictionary	,
		(const dictionary &XiProperties, const hhuCombustionThermo &thermo, const compressible::RASModel &turbulence, const volScalarField &Su, const volScalarField &rho, const volScalarField &b, const surfaceScalarField &phi)	,
		(XiProperties, thermo, turbulence, Su, rho, b, phi)
	)

static autoPtr<XiModel> New	(	const dictionary &	XiProperties,
		const hhuCombustionThermo &	thermo,
		const compressible::RASModel &	turbulence,
		const volScalarField &	Su,
		const volScalarField &	rho,
		const volScalarField &	b,
		const surfaceScalarField &	phi
	)		`[static]`