Properties🔗

• One equation model based on a modified turbulence viscosity, \(\tilde{\nu}\)

Model equations🔗

\[\Ddt{\rho \tilde{\nu}} = \div \left( \rho D_\tilde{\nu} \tilde{\nu} \right) + \frac{C_{b2}}{\sigma_{\nu_t}} \rho \mag{\grad \tilde{\nu}}^2 + C_{b1} \rho \tilde{S} \tilde{\nu} \left(1 - f_{t2}\right) - \left(C_{w1} f_w - \frac{C_{b1}}{\kappa^2} f_{t2}\right) \rho \frac{\tilde{\nu}^2}{\tilde{d}^2} + S_\tilde{\nu}\]

The \(f_{t2}\) term is not implemented.

The turbulence viscosity is obtained using:

\[\nu_t = \tilde{\nu} f_{v1}\]

where the function \(f_{v1}\) is given by

\[f_{v1} = \frac{\chi^3}{\chi^3 + C_{v1}^3}\]

and

\[\chi = \frac{\tilde{\nu}}{\nu}\]

Default model coefficients🔗

Usage🔗

The model is specified using:

RAS
{
    turbulence      on;
    RASModel        SpalartAllmaras;
}

Further information🔗

Source code:

• Foam::RASModels::SpalartAllmaras

References:

• Standard model: Spalart [69]

Related:

• DES variants, e.g.
• SpalartAllmarasDES