Turbulence far-field state selection

Turbulence variables at far-field faces follow the mean-flow normal direction: interior values when fluid leaves the domain, freestream turbulence when fluid enters.

\[\text{use interior} \iff v_n \ge 0\]

Supersonic: (v_n) is the interior normal velocity. Subsonic: (v_n) is the Riemann-combined boundary normal velocity (same acoustic practice as the NS far-field).

References

• Characteristic far-field practice; NASA TMR turbulence BC notes.

• See turb_wall_bc.rst and farfield_riemann.rst.

Pure API: TurbFarfieldUsesInterior.