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atmBoundaryLayerInletVelocity

# Properties

• The atmBoundaryLayerInletVelocity boundary condition provides a generalised log-law type ground-normal inlet boundary condition for the streamwise component of wind velocity, i.e. u, for homogeneous, two-dimensional, dry-air, equilibrium and neutral atmospheric boundary layer modelling.
• The atmBoundaryLayerInletVelocity boundary condition inherits the traits of the atmBoundaryLayer, and inletOutlet.

# Model equations

The ground-normal streamwise flow speed profile expression ((, Table 1), (, Eq. 6), (, Eq. 5)):

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

$v = w = 0$

where

 $$u$$ = Ground-normal streamwise flow speed profile [m/s] $$v$$ = Spanwise flow speed [m/s] $$w$$ = Ground-normal flow speed [m/s] $$u^*$$ = Friction velocity [m/s] $$\kappa$$ = von Kármán constant [-] $$z$$ = Ground-normal coordinate component [m] $$d$$ = Ground-normal displacement height [m] $$z_0$$ = Aerodynamic roughness length [m]

# Usage

Example of the boundary condition specification:

inlet
{
// Mandatory entries (unmodifiable)
type            atmBoundaryLayerInletVelocity;

// 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 Required Default
type Type name: atmBoundaryLayerInletVelocity word yes -

The inherited entries are elaborated in:

# Further information

Tutorial:

Source code:

History

• Introduced in version 1.7.0