atmPlantCanopyTurbSource
applies sources on either epsilon
or omega
to incorporate effects of plant canopy for atmospheric boundary layer modelling.atmPlantCanopyTurbSource
can be applied on epsilon
or omega
based RAS turbulence models.atmPlantCanopyTurbSource
inherits the traits of the fvOption, and cellSetOption
.Corrections applied to either of the below, if exist:
epsilon | Turbulent kinetic energy dissipation rate [m2/s3] omega | Specific dissipation rate [1/s]
Required fields:
epsilon/omega | Dissipation rate OR Spec. dissipation rate [m2/s3]/[1/s] plantCd | Plant canopy drag coefficient [-] leafAreaDensity | Leaf area density [1/m]
The model expression for epsilon
:
\[ S_p -= \alpha \rho \left( C_1 - C_2 \right) C_{canopy} \epsilon \]
with ([69], Eq. 42):
\[ C_{canopy} = 12.0 \sqrt{C_\mu} C_d {LAD} |\u_o| \]
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 |
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:
cellSetOption
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