For slip walls, the face value of velocity is computed by extrapolating the parallel component of velocity in the adjacent cell using reconstruction gradients.
For no-slip walls the tangential velocity is explicitly set either to zero (for the case of no wall motion) or to a specified value.
The boundary face static pressure is extrapolated from the adjacent cell using reconstruction gradients.
For inviscid flow, the face value of temperature is extrapolated from the adjacent cell using reconstruction gradients.
For viscous flows, either the temperature or the heat flux is specified. If the heat flux is specified, the wall boundary temperature is computed from the appropriate laminar or turbulent heat flux relationship.