Spalart-Allmaras one-transport-equation linear-eddy-viscosity turbulence closure model for incompressible and compressible external flows. More...

Inheritance diagram for SpalartAllmaras< BasicTurbulenceModel >:

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Collaboration diagram for SpalartAllmaras< BasicTurbulenceModel >:

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Public Types
typedef BasicTurbulenceModel::alphaField	alphaField

typedef BasicTurbulenceModel::rhoField	rhoField

typedef BasicTurbulenceModel::transportModel	transportModel

Public Types inherited from eddyViscosity< RASModel< BasicTurbulenceModel > >
typedef BasicTurbulenceModel::alphaField	alphaField

typedef BasicTurbulenceModel::rhoField	rhoField

typedef BasicTurbulenceModel::transportModel	transportModel

Public Types inherited from linearViscousStress< BasicTurbulenceModel >
typedef BasicTurbulenceModel::alphaField	alphaField

typedef BasicTurbulenceModel::rhoField	rhoField

typedef BasicTurbulenceModel::transportModel	transportModel

Public Member Functions
	TypeName ("SpalartAllmaras")
	Runtime type information. More...

	SpalartAllmaras (const alphaField &alpha, const rhoField &rho, const volVectorField &U, const surfaceScalarField &alphaRhoPhi, const surfaceScalarField &phi, const transportModel &transport, const word &propertiesName=turbulenceModel::propertiesName, const word &type=typeName)
	Construct from components. More...

virtual	~SpalartAllmaras ()=default
	Destructor. More...

virtual bool	read ()
	Re-read model coefficients if they have changed. More...

tmp< volScalarField >	DnuTildaEff () const
	Return the effective diffusivity for nuTilda. More...

virtual tmp< volScalarField >	k () const
	Return the (estimated) turbulent kinetic energy. More...

virtual tmp< volScalarField >	epsilon () const
	Return the (estimated) turbulent kinetic energy dissipation rate. More...

virtual tmp< volScalarField >	omega () const
	Return the (estimated) specific dissipation rate. More...

virtual void	correct ()
	Solve the turbulence equations and correct the turbulent viscosity. More...

Public Member Functions inherited from eddyViscosity< RASModel< BasicTurbulenceModel > >
	eddyViscosity (const word &modelName, const alphaField &alpha, const rhoField &rho, const volVectorField &U, const surfaceScalarField &alphaRhoPhi, const surfaceScalarField &phi, const transportModel &transport, const word &propertiesName)
	Construct from components. More...

virtual	~eddyViscosity ()=default
	Destructor. More...

virtual bool	read ()=0
	Re-read model coefficients if they have changed. More...

virtual tmp< volScalarField >	nut () const
	Return the turbulence viscosity. More...

virtual tmp< scalarField >	nut (const label patchi) const
	Return the turbulence viscosity on patch. More...

virtual tmp< volScalarField >	k () const=0
	Return the turbulence kinetic energy. More...

virtual tmp< volSymmTensorField >	R () const
	Return the Reynolds stress tensor. More...

virtual void	validate ()
	Validate the turbulence fields after construction. More...

virtual void	correct ()=0
	Solve the turbulence equations and correct the turbulence viscosity. More...

Public Member Functions inherited from linearViscousStress< BasicTurbulenceModel >
	linearViscousStress (const word &modelName, const alphaField &alpha, const rhoField &rho, const volVectorField &U, const surfaceScalarField &alphaRhoPhi, const surfaceScalarField &phi, const transportModel &transport, const word &propertiesName)
	Construct from components. More...

virtual	~linearViscousStress ()=default
	Destructor. More...

virtual bool	read ()=0
	Re-read model coefficients if they have changed. More...

virtual tmp< volSymmTensorField >	devRhoReff () const
	Return the effective stress tensor. More...

virtual tmp< volSymmTensorField >	devRhoReff (const volVectorField &U) const
	Return the effective stress tensor based on a given velocity field. More...

virtual tmp< fvVectorMatrix >	divDevRhoReff (volVectorField &U) const
	Return the source term for the momentum equation. More...

virtual tmp< fvVectorMatrix >	divDevRhoReff (const volScalarField &rho, volVectorField &U) const
	Return the source term for the momentum equation. More...

virtual void	correct ()=0
	Solve the turbulence equations and correct the turbulence viscosity. More...

Protected Member Functions
tmp< volScalarField >	chi () const

tmp< volScalarField >	fv1 (const volScalarField &chi) const

tmp< volScalarField::Internal >	fv2 (const volScalarField::Internal &chi, const volScalarField::Internal &fv1) const

tmp< volScalarField::Internal >	Stilda () const

tmp< volScalarField::Internal >	fw (const volScalarField::Internal &Stilda) const

virtual void	correctNut ()
	Update nut with the latest available nuTilda. More...

virtual void	correctNut ()=0

Protected Attributes
dimensionedScalar	sigmaNut_

dimensionedScalar	kappa_

dimensionedScalar	Cb1_

dimensionedScalar	Cb2_

dimensionedScalar	Cw1_

dimensionedScalar	Cw2_

dimensionedScalar	Cw3_

dimensionedScalar	Cv1_

dimensionedScalar	Cs_

volScalarField	nuTilda_
	Modified kinematic viscosity [m2/s]. More...

const volScalarField::Internal &	y_
	Wall distance. More...

Protected Attributes inherited from eddyViscosity< RASModel< BasicTurbulenceModel > >
volScalarField	nut_

Detailed Description

template<class BasicTurbulenceModel>
class Foam::RASModels::SpalartAllmaras< BasicTurbulenceModel >

Spalart-Allmaras one-transport-equation linear-eddy-viscosity turbulence closure model for incompressible and compressible external flows.

Required fields

    nuTilda   | Modified kinematic viscosity [m2/s]

References:

    Standard model:
        Spalart, P.R., & Allmaras, S.R. (1994).
        A one-equation turbulence model for aerodynamic flows.
        La Recherche Aerospatiale, 1, 5-21.

    Standard model without trip and ft2 terms (tag:R):
        Rumsey, C. (2020).
        The Spalart-Allmaras Turbulence Model.
        Spalart-Allmaras One-Equation Model without ft2 Term (SA-noft2).
        https://turbmodels.larc.nasa.gov/spalart.html#sanoft2
        (Retrieved:12-01-2021).

    Estimation expression for k and epsilon (tag:B), Eq. 4.50:
        Bourgoin, A. (2019).
        Bathymetry induced turbulence modelling the
        Alderney Race site: regional approach with TELEMAC-LES.
        Normandie Université.

    Estimation expressions for omega (tag:P):
        Pope, S. B. (2000).
        Turbulent flows.
        Cambridge, UK: Cambridge Univ. Press
        DOI:10.1017/CBO9780511840531

Usage

Example by using constant/turbulenceProperties:

RAS
{
    // Mandatory entries (unmodifiable)
    RASModel        SpalartAllmaras;

    // Optional entries (runtime modifiable)
    turbulence      on;
    printCoeffs     on;

    SpalartAllmarasCoeffs
    {
        sigmaNut    0.66666;
        kappa       0.41;
        Cb1         0.1355;
        Cb2         0.622;
        Cw2         0.3;
        Cw3         2.0;
        Cv1         7.1;
        Cs          0.3;
    }
}

Note

The model is implemented without the trip-term since the model has almost always been used in fully turbulent applications rather than those where laminar-turbulent transition occurs.
It has been argued that the ft2 term is not needed in the absence of the trip-term, hence ft2 term is also not implementated.
The Stilda generation term should never be allowed to be zero or negative to avoid potential numerical issues and unphysical results for complex flows. To this end, a limiter proposed by Spalart (R:Note-1(b)) is applied onto Stilda where Stilda is clipped at Cs*Omega with the default value of Cs=0.3.
The model does not produce k, epsilon or omega. Nevertheless, these quantities can be estimated by using an approximate expressions for turbulent kinetic energy and dissipation rate reported in (B:Eq. 4.50).

Source files

Definition at line 132 of file SpalartAllmaras.H.

Member Typedef Documentation

◆ alphaField

typedef BasicTurbulenceModel::alphaField alphaField

Definition at line 199 of file SpalartAllmaras.H.

◆ rhoField

typedef BasicTurbulenceModel::rhoField rhoField

Definition at line 200 of file SpalartAllmaras.H.

◆ transportModel

typedef BasicTurbulenceModel::transportModel transportModel

Definition at line 201 of file SpalartAllmaras.H.

Constructor & Destructor Documentation

◆ SpalartAllmaras()

SpalartAllmaras	(	const alphaField &	alpha,
		const rhoField &	rho,
		const volVectorField &	U,
		const surfaceScalarField &	alphaRhoPhi,
		const surfaceScalarField &	phi,
		const transportModel &	transport,
		const word &	propertiesName = `turbulenceModel::propertiesName`,
		const word &	type = `typeName`
	)