### 12.4.2. Boundary Conditions for SRS

#### 12.4.2.1. Inlet Conditions

Inlet conditions should be selected based on the physics of the flow and applied in a similar manner as RANS computations.

For global models (SAS, DDES/SDES/SBES), use standard (typically steady-state) RANS inlet conditions.

For LES or WMLES, provide synthetic turbulence at the inlet.

#### 12.4.2.2. Outlet Conditions

If possible, outflow or average pressure is better than constant pressure outlets as vortices carry non-constant pressure distributions across the boundary. For certain acoustics calculations, like jet noise, use non-reflecting boundary conditions.

#### 12.4.2.3. Wall Conditions

For all models except LES, use low values of around . The models are formulated in a -insensitive fashion, so larger values of can be tolerated as long as the overall boundary layer resolution is sufficient.

For LES, one would typically have to apply wall functions in order to avoid the large resolution requirements near the wall. The wall resolution in streamwise (), normal () and spanwise () directions are coupled.

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