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:

DES model coefficients:

Initialisation🔗

Usage🔗

The model is specified using:

LES
{
    turbulence      on;
    LESModel        kOmegaSSTDES;
}

Boundary conditions🔗

Inlet

• fixedValue

Outlet

• Constrained outlet

Walls

• wall functions

Further information🔗

Source code:

• Foam::LESModels::kOmegaSSTDES

References:

• Strelets [74]

See also:

• Base k-omega SST model