Base class to set log-law type ground-normal inlet boundary conditions for wind velocity and turbulence quantities for homogeneous, two-dimensional, dry-air, equilibrium and neutral atmospheric boundary layer (ABL) modelling. More...

Inheritance diagram for atmBoundaryLayer:

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Public Member Functions
	atmBoundaryLayer (const Time &time, const polyPatch &pp)
	Construct null from time. More...

	atmBoundaryLayer (const Time &time, const polyPatch &pp, const dictionary &dict)
	Construct from the time database and dictionary. More...

	atmBoundaryLayer (const atmBoundaryLayer &abl, const fvPatch &patch, const fvPatchFieldMapper &mapper)
	Construct by mapping given atmBoundaryLayer onto a new patch. More...

	atmBoundaryLayer (const atmBoundaryLayer &)
	Construct as copy. More...

vector	flowDir () const
	Return flow direction. More...

vector	zDir () const
	Return the ground-normal direction. More...

tmp< scalarField >	Ustar (const scalarField &z0) const
	Return friction velocity. More...

void	autoMap (const fvPatchFieldMapper &)
	Map (and resize as needed) from self given a mapping object. More...

void	rmap (const atmBoundaryLayer &, const labelList &)
	Reverse map the given fvPatchField onto this fvPatchField. More...

tmp< vectorField >	U (const vectorField &pCf) const
	Return the velocity distribution for the ATM. More...

tmp< scalarField >	k (const vectorField &pCf) const
	Return the turbulent kinetic energy distribution for the ATM. More...

tmp< scalarField >	epsilon (const vectorField &pCf) const
	Return the turbulent dissipation rate distribution for the ATM. More...

tmp< scalarField >	omega (const vectorField &pCf) const
	Return the specific dissipation rate distribution for the ATM. More...

void	write (Ostream &) const
	Write. More...

Protected Attributes
bool	initABL_

Detailed Description

Base class to set log-law type ground-normal inlet boundary conditions for wind velocity and turbulence quantities for homogeneous, two-dimensional, dry-air, equilibrium and neutral atmospheric boundary layer (ABL) modelling.

The ground-normal profile expressions are due to YGCJ (refer to references below) whereat RH expressions were generalised:

\[ u = \frac{u^*}{\kappa} \ln \left( \frac{z - d + z_0}{z_0} \right) \]

\[ v = w = 0 \]

\[ k = \frac{(u^*)^2}{\sqrt{C_\mu}} \sqrt{C_1 \ln \left( \frac{z - d + z_0}{z_0} \right) + C_2} \]

\[ \epsilon = \frac{(u^*)^3}{\kappa (z - d + z_0)} \sqrt{C_1 \ln \left( \frac{z - d + z_0}{z_0} \right) + C_2} \]

\[ \omega = \frac{u^*}{\kappa \sqrt{C_\mu}} \frac{1}{z - d + z_0} \]

\[ u^* = \frac{u_{ref} \kappa}{\ln\left(\frac{z_{ref} + z_0}{z_0}\right)} \]

where

\( u \)	=	Ground-normal streamwise flow speed profile [m/s]
\( v \)	=	Spanwise flow speed [m/s]
\( w \)	=	Ground-normal flow speed [m/s]
\( k \)	=	Ground-normal turbulent kinetic energy (TKE) profile [m^2/s^2]
\( \epsilon \)	=	Ground-normal TKE dissipation rate profile [m^2/s^3]
\( \omega \)	=	Ground-normal specific dissipation rate profile [m^2/s^3]
\( u^* \)	=	Friction velocity [m/s]
\( \kappa \)	=	von Kármán constant [-]
\( C_\mu \)	=	Empirical model constant [-]
\( z \)	=	Ground-normal coordinate component [m]
\( d \)	=	Ground-normal displacement height [m]
\( z_0 \)	=	Aerodynamic roughness length [m]
\( u_{ref} \)	=	Reference mean streamwise wind speed at \(z_{ref}\) [m/s]
\( z_{ref} \)	=	Reference height being used in \(u^*\) estimations [m]
\( C_1 \)	=	Curve-fitting coefficient for `YGCJ` profiles [-]
\( C_2 \)	=	Curve-fitting coefficient for `YGCJ` profiles [-]

Reference:

        The ground-normal profile expressions (tag:RH):
            Richards, P. J., & Hoxey, R. P. (1993).
            Appropriate boundary conditions for computational wind
            engineering models using the k-ε turbulence model.
            In Computational Wind Engineering 1 (pp. 145-153).
            DOI:10.1016/B978-0-444-81688-7.50018-8

        Modifications to preserve the profiles downstream (tag:HW):
            Hargreaves, D. M., & Wright, N. G. (2007).
            On the use of the k–ε model in commercial CFD software
            to model the neutral atmospheric boundary layer.
            Journal of wind engineering and
            industrial aerodynamics, 95(5), 355-369.
            DOI:10.1016/j.jweia.2006.08.002

        Expression generalisations to allow height
        variation for turbulence quantities (tag:YGCJ):
            Yang, Y., Gu, M., Chen, S., & Jin, X. (2009).
            New inflow boundary conditions for modelling the neutral equilibrium
            atmospheric boundary layer in computational wind engineering.
            J. of Wind Engineering and Industrial Aerodynamics, 97(2), 88-95.
            DOI:10.1016/j.jweia.2008.12.001

        The generalised ground-normal profile expression for omega (tag:YGJ):
            Yang, Y., Gu, M., & Jin, X., (2009).
            New inflow boundary conditions for modelling the
            neutral equilibrium atmospheric boundary layer in SST k-ω model.
            In: The Seventh Asia-Pacific Conference on Wind Engineering,
            November 8-12, Taipei, Taiwan.

        Theoretical remarks (tag:E):
            Emeis, S. (2013).
            Wind Energy Meteorology: Atmospheric
            Physics for Wind Power Generation.
            Springer-Verlag Berlin Heidelberg.
            DOI:10.1007/978-3-642-30523-8

Usage

Example of the entries provided for the inherited boundary conditions:

inlet
{
    // Mandatory and other optional entries
    ...

    // Mandatory (inherited) entries (runtime modifiable)
    flowDir         (1 0 0);
    zDir            (0 0 1);
    Uref            10.0;
    Zref            0.0;
    z0              uniform 0.1;
    d               uniform 0.0;

    // Optional (inherited) entries (unmodifiable)
    kappa           0.41;
    Cmu             0.09;
    initABL         true;
    phi             phi;
    C1              0.0;
    C2              1.0;

    // Conditional mandatory (inherited) entries (runtime modifiable)
    value           uniform 0;    // when initABL=false
}

where the entries mean:

Property	Description	Type	Reqd	Deflt
`flowDir`	Flow direction	Function1<vector>	yes	-
`zDir`	Ground-normal direction	Function1<vector>	yes	-
`Uref`	Reference mean streamwise flow speed being used in \(u^*\) estimations [m/s]	Function1<scalar>	yes	-
`Zref`	Reference height being used in \(u^*\) estimations [m]	Function1<scalar>	yes	-
`z0`	Surface roughness length [m]	PatchFunction1<scalar>	yes	-
`d`	Displacement height [m] - see Notes	PatchFunction1<scalar>	yes	-
`kappa`	von Kármán constant	scalar	no	0.41
`Cmu`	Empirical model constant	scalar	no	0.09
`initABL`	Flag to initialise profiles with the theoretical ABL expressions, otherwise use "value" list	bool	no	true
`value`	ABL profile content when initABL=false	scalarList	conditional	-
`phi`	Name of the flux field	word	no	phi
`C1`	Curve-fitting coefficient `YGCJ` profiles	scalar	no	0.0
`C2`	Curve-fitting coefficient `YGCJ` profiles	scalar	no	1.0

Note

The RH expressions are special cases of those in YGCJ when C1=0 and C2=1. Both C1 and C2 can be determined by nonlinear fitting of (YGCJ:Eqs. 19-20) with an experimental dataset for k. By default, atmBoundaryLayerInlet boundary conditions compute RH expressions.
z is the ground-normal height relative to the global minimum height of the inlet patch; therefore, the minimum of z is always zero irrespective of the absolute z-coordinate of the computational patch.
The derived ABL expressions automatically satisfy the simplified transport equation for k. Yet the same expressions only satisfy the simplified transport equation for epsilon when the model constants sigmaEpsilon is 1.11 with kappa=0.4 (HW:p. 358).
atmBoundaryLayerInlet boundary conditions inherit inletOutlet traits, so that a given inlet condition can be supplied from all sides of the domain, e.g. a ground-normal cylinder domain having a single inlet/outlet boundary where the changes between inlet and outlet depend on the wind direction and patch normals, so that any change in inflow orientation can be handled with the same mesh.
d is the displacement height, and "is relevant for flows over forests and cities" (E:p. 28). "The displacement height gives the vertical displacement of the entire flow regime over areas which are densely covered with obstacles such as trees or buildings" (E:p. 28).

See also

Source files

Definition at line 393 of file atmBoundaryLayer.H.

Constructor & Destructor Documentation

◆ atmBoundaryLayer() [1/4]

atmBoundaryLayer	(	const Time &	time,
		const polyPatch &	pp
	)

Construct null from time.

Definition at line 38 of file atmBoundaryLayer.C.

◆ atmBoundaryLayer() [2/4]

atmBoundaryLayer	(	const Time &	time,
		const polyPatch &	pp,
		const dictionary &	dict
	)

Construct from the time database and dictionary.

Definition at line 58 of file atmBoundaryLayer.C.

◆ atmBoundaryLayer() [3/4]

atmBoundaryLayer	(	const atmBoundaryLayer &	abl,
		const fvPatch &	patch,
		const fvPatchFieldMapper &	mapper
	)

Construct by mapping given atmBoundaryLayer onto a new patch.

Definition at line 85 of file atmBoundaryLayer.C.

◆ atmBoundaryLayer() [4/4]

atmBoundaryLayer ( const atmBoundaryLayer & abl )

Construct as copy.

Definition at line 108 of file atmBoundaryLayer.C.

Member Function Documentation

◆ flowDir()

vector flowDir ( ) const

Return flow direction.

Definition at line 129 of file atmBoundaryLayer.C.

References Foam::abort(), Foam::FatalError, FatalErrorInFunction, Foam::mag(), and TimeState::timeOutputValue().

Referenced by atmBoundaryLayer::U().

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◆ zDir()

vector zDir ( ) const

Return the ground-normal direction.

Definition at line 147 of file atmBoundaryLayer.C.

References Foam::abort(), Foam::FatalError, FatalErrorInFunction, Foam::mag(), and TimeState::timeOutputValue().

Referenced by atmBoundaryLayer::epsilon(), atmBoundaryLayer::k(), atmBoundaryLayer::omega(), and atmBoundaryLayer::U().

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◆ Ustar()

tmp< scalarField > Ustar ( const scalarField & z0 ) const

Return friction velocity.

Definition at line 165 of file atmBoundaryLayer.C.

References Foam::abort(), Foam::FatalError, FatalErrorInFunction, Foam::log(), and TimeState::timeOutputValue().

Referenced by atmBoundaryLayer::epsilon(), atmBoundaryLayer::k(), atmBoundaryLayer::omega(), and atmBoundaryLayer::U().

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◆ autoMap()

void autoMap ( const fvPatchFieldMapper & mapper )

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

Definition at line 183 of file atmBoundaryLayer.C.

Referenced by atmBoundaryLayerInletKFvPatchScalarField::autoMap(), atmBoundaryLayerInletOmegaFvPatchScalarField::autoMap(), atmBoundaryLayerInletEpsilonFvPatchScalarField::autoMap(), and atmBoundaryLayerInletVelocityFvPatchVectorField::autoMap().

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◆ rmap()

void rmap	(	const atmBoundaryLayer &	abl,
		const labelList &	addr
	)

Reverse map the given fvPatchField onto this fvPatchField.

Definition at line 197 of file atmBoundaryLayer.C.

Referenced by atmBoundaryLayerInletKFvPatchScalarField::rmap(), atmBoundaryLayerInletOmegaFvPatchScalarField::rmap(), atmBoundaryLayerInletEpsilonFvPatchScalarField::rmap(), and atmBoundaryLayerInletVelocityFvPatchVectorField::rmap().

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◆ U()

tmp< vectorField > U ( const vectorField & pCf ) const

Return the velocity distribution for the ATM.

Definition at line 213 of file atmBoundaryLayer.C.

References atmBoundaryLayer::flowDir(), Foam::log(), Foam::max(), TimeState::timeOutputValue(), atmBoundaryLayer::Ustar(), and atmBoundaryLayer::zDir().

Referenced by atmBoundaryLayerInletVelocityFvPatchVectorField::updateCoeffs().

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◆ k()

tmp< scalarField > k ( const vectorField & pCf ) const

Return the turbulent kinetic energy distribution for the ATM.

Definition at line 230 of file atmBoundaryLayer.C.

References Foam::log(), Foam::max(), Foam::sqr(), Foam::sqrt(), TimeState::timeOutputValue(), atmBoundaryLayer::Ustar(), and atmBoundaryLayer::zDir().

Referenced by atmBoundaryLayerInletKFvPatchScalarField::updateCoeffs().

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◆ epsilon()

tmp< scalarField > epsilon ( const vectorField & pCf ) const

Return the turbulent dissipation rate distribution for the ATM.

Definition at line 244 of file atmBoundaryLayer.C.

References Foam::log(), Foam::max(), Foam::pow3(), Foam::sqrt(), TimeState::timeOutputValue(), atmBoundaryLayer::Ustar(), and atmBoundaryLayer::zDir().

Referenced by atmBoundaryLayerInletEpsilonFvPatchScalarField::updateCoeffs().

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◆ omega()

tmp< scalarField > omega ( const vectorField & pCf ) const

Return the specific dissipation rate distribution for the ATM.

Definition at line 258 of file atmBoundaryLayer.C.

References Foam::max(), Foam::sqrt(), TimeState::timeOutputValue(), atmBoundaryLayer::Ustar(), and atmBoundaryLayer::zDir().

Referenced by atmBoundaryLayerInletOmegaFvPatchScalarField::updateCoeffs().

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◆ write()

void write ( Ostream & os ) const

Write.

Definition at line 270 of file atmBoundaryLayer.C.

References atmBoundaryLayer::initABL_, and os().

Referenced by atmBoundaryLayerInletKFvPatchScalarField::write(), atmBoundaryLayerInletOmegaFvPatchScalarField::write(), atmBoundaryLayerInletEpsilonFvPatchScalarField::write(), and atmBoundaryLayerInletVelocityFvPatchVectorField::write().

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Member Data Documentation

◆ initABL_

bool initABL_

protected

Flag to initialise profiles with the theoretical ABL expressions, otherwise initialises by using "value" entry content

Definition at line 401 of file atmBoundaryLayer.H.

Referenced by atmBoundaryLayer::write().

The documentation for this class was generated from the following files:

src/atmosphericModels/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.H
src/atmosphericModels/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ atmBoundaryLayer() [1/4]

◆ atmBoundaryLayer() [2/4]

◆ atmBoundaryLayer() [3/4]

◆ atmBoundaryLayer() [4/4]

Member Function Documentation

◆ flowDir()

◆ zDir()

◆ Ustar()

◆ autoMap()

◆ rmap()

◆ U()

◆ k()

◆ epsilon()

◆ omega()

◆ write()

Member Data Documentation

◆ initABL_