Interior Impedance

Use the condition to specify a specific transfer impedance on an interior boundary. The impedance can be any expression and can, for example, be a function of the frequency (freq). The condition is based on the Ingard-Myers condition, see Ref. 1 and About the Impedance Boundary Condition located in the Theory Background for the Aeroacoustics Branch section. The condition is a so-called low frequency approximation; the viscous boundary layer of the background flow is assumed infinitely thin at the impedance wall.

Interior Impedance (Ingard-Myers)

Enter the value of the Zn (SI unit: Pa·s/m). This can be an analytical expression or data provided through an interpolation function. Click to select the check box, if the impedance is at a boundary with no normal velocity component for the background flow, u0·n = 0. This simplifies the equations that are solved for in the boundary condition.

Constraint Settings

To display this section, click the button (

) and select in the dialog box.

Excluded Edges/Points

To display this section, click the button (

) and select in the dialog box. See Suppressing Constraints on Lower Dimensions for details.


	For systems with a trailing edge on an airfoil or with an edge singularity between a liner and a rigid wall, the exclude edges and points functionality can be used to set up an appropriate Kutta condition. See Suppressing Constraints on Lower Dimensions.