Spalart-Allmaras

Properties

\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}

$\sigma_{\nu_t}$	$C_{b1}$	$C_{b2}$	$C_{w1}$	$C_{w2}$	$C_{w3}$
2/3	0.1355	0.622	$\frac{C_{b1}}{\kappa^2} + \frac{1 + C_{b2}}{\sigma_{\nu_t}}$	0.3	2

$C_{v1}$	$C_{s}$
7.1	0.3

The model is specified using:

RAS
{
    turbulence      on;
    RASModel        SpalartAllmaras;
}

Source code:

References: