## Properties🔗

• The atmPlantCanopyTurbSource applies sources on either epsilon or omega to incorporate effects of plant canopy for atmospheric boundary layer modelling.
• The atmPlantCanopyTurbSource can be applied on epsilon or omega based RAS turbulence models.
• The atmPlantCanopyTurbSource inherits the traits of the fvOption, and cellSetOption.

Corrections applied to either of the below, if exist:

epsilon
Turbulent kinetic energy dissipation rate [m$$^2$$/s$$^3$$]
omega
Specific dissipation rate [1/s]

epsilon/omega
Dissipation rate OR Spec. dissipation rate [m$$^2$$/s$$^3$$]/[1/s]
plantCd
Plant canopy drag coefficient [-]
leafAreaDensity
Leaf area density [1/m]

## Model equations🔗

### Turbulent kinetic energy dissipation rate🔗

The model expression for epsilon:

$S_p -= \alpha \rho \left( C_1 - C_2 \right) C_{canopy} \epsilon$

with (, Eq. 42):

$C_{canopy} = 12.0 \sqrt{C_\mu} C_d {LAD} |\u_o|$

### Specific dissipation rate🔗

The model expression for omega:

$S_p -= \alpha \rho \left( \gamma - \beta \right) C_{canopy} \omega$

Where:

$$S_p$$
Source term without boundary conditions
$$C_1$$
Model constant (epsilon-based models) [-]
$$C_2$$
Model constant (epsilon-based models) [-]
$$C_\mu$$
Empirical model constant [-]
$$\beta$$
Model constant (omega-based models) [-]
$$\gamma$$
Model constant (omega-based models) [-]
$$\epsilon$$
Turbulent kinetic energy dissipation rate (Current iteration) [m2/s3]
$$\omega$$
Specific dissipation rate (Current iteration) [1/s]
$$C_d$$
Plant canopy drag coefficient [-]
$${LAD}$$
Leaf area density [1/m]
$$\u_o$$
Previous-iteration velocity field [m/s]
$$C_{canopy}$$
Plant canopy term
$$\alpha$$
Phase fraction in multiphase computations, otherwise equals to 1
$$\rho$$
Fluid density in compressible computations, otherwise equals to 1

## Usage🔗

Example of the fvOptions specification using constant/fvOptions file:

atmPlantCanopyTurbSource1
{
// Mandatory entries (unmodifiable)
type                  atmPlantCanopyTurbSource;

atmPlantCanopyTurbSourceCoeffs
{
// Mandatory (inherited) entries (unmodifiable)
selectionMode    all;

// Optional entries (unmodifiable)
rho             rho;
}

// Optional (inherited) entries
...
}


where the entries mean:

Property Description Type Required Default
type Type name: atmPlantCanopyTurbSource word yes -
rho Name of density field word no rho

The inherited entries are elaborated in:

## Further information🔗

Tutorials

Source code

History:

• Introduced in version v2006