The Interior Impedance and
Pair Impedance nodes add an impedance boundary condition on interior boundaries or boundaries between the parts of pairs. Add the
Interior Impedance node from the
Interior Conditions submenu. This condition is a generalization of the sound-hard and sound-soft boundary conditions. The condition corresponds to a transfer impedance condition, relating the pressure drop across the boundary
to the velocity at the boundary. In the frequency domain, it imposes the following equations:
Zi is the transfer impedance, which from a physical point, is the ratio between pressure drop and normal particle velocity.
Enter the value of the Impedance Zi (SI unit: Pa·s/m). The default is 0 Pa·s/m.