atmAmbientTurbSource
applies sources on k
and either epsilon
or omega
to prevent them droping below a specified ambient value for atmospheric boundary layer modelling.atmAmbientTurbSource
can be applied on epsilon
or omega
based RAS turbulence models.atmAmbientTurbSource
inherits the traits of the fvOption, and cellSetOption
.Corrections applied to:
k | Turbulent kinetic energy [m2/s2]
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:
k | Turbulent kinetic energy [m2/s2] epsilon/omega | Dissipation rate OR Specific dissipation rate [m2/s3]/[1/s]
The model expression for epsilon
(Heuristically derived from ([64], Eq. 4, rhs-term:5)):
\[ S_p = \alpha \rho C_2 \frac{\epsilon_{amb}^2}{k_{amb} \epsilon_o} \epsilon \]
The model expression for omega
([64], Eq. 4, rhs-term:5):
\[ S_p = \alpha \rho C_\mu \beta \frac{\omega^2_{amb}}{\omega_o} \omega \]
The model expression for k
when epsilon
is available (Heuristically derived from ([64], Eq. 3, rhs-term:4)):
\[ S_p = \alpha \rho \frac{\epsilon_{amb}}{k_o} k \]
The model expression for k
when omega
is available ([64], Eq. 3, rhs-term:4):
\[ S_p = \alpha \rho C_\mu \frac{\omega_{amb} k_{amb}}{k_o} k \]
where
\( S_p \) | = | Source term without boundary conditions |
\( \epsilon \) | = | Turbulent kinetic energy dissipation rate (Current iteration) [m2/s3] |
\( \omega \) | = | Specific dissipation rate (Current iteration) [1/s] |
\( k \) | = | Turbulent kinetic energy (Current iteration) [m2/s2] |
\( \epsilon_{amb} \) | = | Ambient epsilon value [m2/s3] |
\( \omega_{amb} \) | = | Ambient omega value [1/s] |
\( k_{amb} \) | = | Ambient k value [m2/s2] |
\( \epsilon_o \) | = | Previous-iteration epsilon [m2/s3] |
\( \omega_o \) | = | Previous-iteration omega [1/s] |
\( k_o \) | = | Previous-iteration k [m2/s2] |
\( C_2 \) | = | Model constant [-] |
\( C_\mu \) | = | Empirical model constant [-] |
\( \beta \) | = | Model constant [-] |
\( \alpha \) | = | 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:
atmAmbientTurbSource1 { // Mandatory entries (unmodifiable) type atmAmbientTurbSource; atmAmbientTurbSourceCoeffs { // Mandatory (inherited) entries (unmodifiable) selectionMode all; // Mandatory entries (unmodifiable) kAmb 0.0; // Optional entries (unmodifiable) rho rho; epsilonAmb 0.0; omegaAmb 0.0; } // Optional (inherited) entries ... }
where the entries mean:
Property | Description | Type | Required | Default |
---|---|---|---|---|
type | Type name: atmAmbientTurbSource | word | yes | - |
kAmb | Ambient value for k | scalar | yes | - |
rho | Name of density field | word | no | rho |
epsilonAmb | Ambient value for epsilon | scalar | no | 0.0 |
omegaAmb | Ambient value for omega | scalar | no | 0.0 |
The inherited entries are elaborated in:
cellSetOption
Tutorials
Source code
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