Properties🔗
- Two equation model for the turbulence kinetic energy, \(k\), and turbulence specific dissipation rate, \(\omega\).
- Based on the k-omega SST model
Model equations🔗
The turbulence specific dissipation rate equation is given by:
\[\Ddt{\rho \omega} = \div \left( \rho D_\omega \grad \omega \right) + \rho \gamma \frac{G}{\nu} - \frac{2}{3} \rho \gamma \omega \left( \div \u \right) - \rho \beta \omega^2 - \rho \left( F_1 - 1 \right) CD_{k \omega} + S_\omega,\]and the turbulence kinetic energy by:
\[\Ddt{\rho k} = \div \left( \rho D_k \grad k \right) + \min\left( \rho G, \left(c_1 \beta^{*}\right) \rho k \omega \right) - \frac{2}{3} \rho k \left( \div \u \right) - \rho \frac{k^{1.5}}{\tilde{d}} + S_k.\]The length scale, \(\tilde{d}\), is given by:
\[\min \left(C_{DES} \Delta, \frac{\sqrt{k}}{\beta^{*} \omega}\right)\]The turbulence viscosity is obtained using:
\[\nu_t = a_1 \frac{k}{\max (a_1 \omega_, b_1 F_{23} \tensor{S})}\]Default model coefficients🔗
Base model coefficients:
\(\alpha_{k1}\) | \(\alpha_{k2}\) | \(\alpha_{\omega 1}\) | \(\alpha_{\omega 2}\) | \(\beta_1\) | \(\beta_2\) | \(\gamma_1\) | \(\gamma_2\) |
---|---|---|---|---|---|---|---|
0.85 | 1.0 | 0.5 | 0.856 | 0.075 | 0.0828 | 5/9 | 0.44 |
\(\beta^{*}\) | \(a_1\) | \(b_1\) | \(c_1\) |
---|---|---|---|
0.09 | 0.31 | 1.0 | 10.0 |
DES model coefficients:
\(CDESkom\) | \(CDESkeps\) |
---|---|
0.82 | 0.6 |
Initialisation🔗
Usage🔗
The model is specified using:
LES
{
turbulence on;
LESModel kOmegaSSTDES;
}
Boundary conditions🔗
Inlet
Outlet
Walls
- wall functions
Further information🔗
Source code:
References:
- Strelets [74]
See also: