Use the Impedance node to specify a normal specific impedance
Zn on a boundary. Add this node from the
Mechanical submenu. This feature is useful outside the viscous boundary layer, as this condition mimics the behavior of a corresponding
Pressure Acoustics Model with a normal impedance condition. The boundary condition reads
Select a condition for the Tangential velocity —
Slip (the default) or
No slip. The
No Slip option will apply an additional constraint for the velocity in the tangential direction on the boundary.